feat: json2go (#130)

* feat(json2go): implement

* feat(json2go): support manual input

* chore(readme): add json2go

* chore(docs): add docs

.github/workflows/tests.yml

@@ -15,6 +15,13 @@ jobs:
         version:
           - stable
           - nightly
+          - v0.10.0
+          - v0.10.4
+          - v0.11.0
+          - v0.11.1
+          - v0.11.2
+          - v0.11.3
+          - v0.11.4
     runs-on: ${{ matrix.os }}
     steps:
       - name: Install Task
@@ -47,14 +54,9 @@ jobs:
           key: ${{ runner.os }}-tests-${{ hashFiles('${{ github.workspace }}/.tests') }}
 
       - name: Install Go bins
-        run: |
+        run: task install-deps
-          # TODO: install with :GoInstallDeps
-          go install github.com/fatih/gomodifytags@latest
-          go install github.com/josharian/impl@latest
-          go install github.com/cweill/gotests/...@latest
-          go install github.com/koron/iferr@latest
 
       - name: Run Tests
         run: |
           nvim --version
-          task tests
+          task test

CONTRIBUTING.md

@@ -1,17 +1,14 @@
 # Contributing to `gopher.nvim`
-
 Thank you for taking the time to submit some code to gopher.nvim. It means a lot!
 
 ### Task running
-
 In this codebase for running tasks is used [Taskfile](https://taskfile.dev).
 You can install it with:
 ```bash
 go install github.com/go-task/task/v3/cmd/task@latest
 ```
 
-### Styling and formatting
+### Formatting and linting
-
 Code is formatted by [stylua](https://github.com/JohnnyMorganz/StyLua) and linted using [selene](https://github.com/Kampfkarren/selene).
 You can install these with:
 
@@ -22,30 +19,31 @@ sudo pacman -S selene stylua
 
 For formatting use this following commands, or setup your editor to integrate with selene/stylua:
 ```bash
-task stylua
+task format
-task lint # lintering and format chewing
+task lint
 ```
 
 ### Documentation
+Here we're using [mini.doc](https://github.com/echasnovski/mini.nvim/blob/main/readmes/mini-doc.md)
+for generating vimhelp files based on [LuaCats](https://luals.github.io/wiki/annotations/) annotations in comments.
 
-Here we are using [mini.doc](https://github.com/echasnovski/mini.nvim/blob/main/readmes/mini-doc.md)
+For demo gifs in [readme](./README.md) we're using [vhs](https://github.com/charmbracelet/vhs).
-for generating help files based on EmmyLua-like annotations in comments
+All files related to demos live in [/vhs](./vhs) dir.
 
 You can generate docs with:
 ```bash
-task docgen
+task docgen       # generates vimhelp
+task vhs:generate # generates demo gifs
 ```
 
 ### Commit messages
-
 We use [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/), please follow it.
 
 ### Testing
-
 For testing this plugins uses [mini.test](https://github.com/echasnovski/mini.nvim/blob/main/readmes/mini-test.md).
 All tests live in [/spec](./spec) dir.
 
 You can run tests with:
 ```bash
-task tests
+task test
 ```

README.md

@@ -4,79 +4,49 @@
 
 Minimalistic plugin for Go development in Neovim written in Lua.
 
-It's **NOT** an LSP tool, the main goal of this plugin is to add go tooling support in Neovim.
+It's **NOT** an LSP tool, the goal of this plugin is to add go tooling support in Neovim.
 
-> If you want to use new and maybe undocumented, and unstable features you might use [develop](https://github.com/olexsmir/gopher.nvim/tree/develop) branch.
+> All development of new and maybe undocumented, and unstable features is happening on [develop](https://github.com/olexsmir/gopher.nvim/tree/develop) branch.
+
+## Table of content
+* [How to install](#install-using-lazynvim)
+* [Features](#features)
+* [Configuration](#configuration)
+* [Troubleshooting](#troubleshooting)
+* [Contributing](#contributing)
 
 ## Install (using [lazy.nvim](https://github.com/folke/lazy.nvim))
 
 Requirements:
 
 - **Neovim 0.10** or later
-- Treesitter `go` parser(`:TSInstall go` if you use [nvim-treesitter](https://github.com/nvim-treesitter/nvim-treesitter))
+- Treesitter parser for `go`(`:TSInstall go` if you use [nvim-treesitter](https://github.com/nvim-treesitter/nvim-treesitter))
-- [Go](https://github.com/golang/go) installed (tested on 1.23)
+- [Go](https://github.com/golang/go) installed
+
+> [!IMPORTANT]
+> If you prefer using other forges, this repository is also mirrored at:
+> - [tangled.org](https://tangled.org): [`https://tangled.org/olexsmir.xyz/gopher.nvim`](https://tangled.org/olexsmir.xyz/gopher.nvim)
+> - [codeberg.org](https://codeberg.org): [`https://codeberg.org/olexsmir/gopher.nvim`](https://codeberg.org/olexsmir/gopher.nvim)
 
 ```lua
+-- NOTE: this plugin is already lazy-loaded and adds only about 1ms
+-- of load time to your config
 {
   "olexsmir/gopher.nvim",
   ft = "go",
   -- branch = "develop"
-  -- (optional) will update plugin's deps on every update
+  -- (optional) updates the plugin's dependencies on each update
   build = function()
     vim.cmd.GoInstallDeps()
   end,
+  ---@module "gopher"
   ---@type gopher.Config
   opts = {},
 }
 ```
 
-## Configuration
-
-> [!IMPORTANT]
->
-> If you need more info look `:h gopher.nvim`
-
-**Take a look at default options (might be a bit outdated, look `:h gopher.nvim-config`)**
-
-```lua
-require("gopher").setup {
-  -- log level, you might consider using DEBUG or TRACE for debugging the plugin
-  log_level = vim.log.levels.INFO,
-
-  -- timeout for running internal commands
-  timeout = 2000,
-
-  commands = {
-    go = "go",
-    gomodifytags = "gomodifytags",
-    gotests = "gotests",
-    impl = "impl",
-    iferr = "iferr",
-  },
-  gotests = {
-    -- gotests doesn't have template named "default" so this plugin uses "default" to set the default template
-    template = "default",
-    -- path to a directory containing custom test code templates
-    template_dir = nil,
-    -- switch table tests from using slice to map (with test name for the key)
-    named = false,
-  },
-  gotag = {
-    transform = "snakecase",
-    -- default tags to add to struct fields
-    default_tag = "json",
-  },
-  iferr = {
-    -- choose a custom error message
-    message = nil,
-  },
-}
-```
-
 ## Features
 
-<!-- markdownlint-disable -->
-
 <details>
   <summary>
     <b>Install plugin's go deps</b>
@@ -92,6 +62,7 @@ require("gopher").setup {
   - [impl](https://github.com/josharian/impl)
   - [gotests](https://github.com/cweill/gotests)
   - [iferr](https://github.com/koron/iferr)
+  - [json2go](https://github.com/olexsmir/json2go)
 </details>
 
 <details>
@@ -99,12 +70,17 @@ require("gopher").setup {
     <b>Add and remove tags for structs via <a href="https://github.com/fatih/gomodifytags">gomodifytags</a></b>
   </summary>
 
+  ![Add tags demo](./vhs/tags.gif)
+
   By default `json` tag will be added/removed, if not set:
 
   ```vim
   " add json tag
   :GoTagAdd json
 
+  " add json tag with omitempty option
+  :GoTagAdd json=omitempty
+
   " remove yaml tag
   :GoTagRm yaml
   ```
@@ -176,6 +152,8 @@ require("gopher").setup {
     <b>Interface implementation via <a href="https://github.com/josharian/impl">impl<a></b>
   </summary>
 
+  ![Auto interface implementation demo](./vhs/impl.gif)
+
   Syntax of the command:
   ```vim
   :GoImpl [receiver] [interface]
@@ -199,6 +177,8 @@ require("gopher").setup {
     <b>Generate boilerplate for doc comments</b>
   </summary>
 
+  ![Generate comments](./vhs/comment.gif)
+
   First set a cursor on **public** package/function/interface/struct and execute:
 
   ```vim
@@ -206,12 +186,32 @@ require("gopher").setup {
   ```
 </details>
 
+<details>
+  <summary>
+    <b>Convert json to Go types</b>
+  </summary>
+
+  ![Convert JSON to Go types](./vhs/json2go.gif)
+
+  `:GoJson` opens a temporary buffer where you can paste or write JSON.
+  Saving the buffer (`:w` or `:wq`) automatically closes it and inserts the generated Go struct into the original buffer at the cursor position.
+
+  Alternatively, you can pass JSON directly as an argument:
+  ```vim
+  :GoJson {"name": "Alice", "age": 30}
+  ```
+
+  Additionally, `gopher.json2go` provides lua api, see `:h gopher.nvim-json2go` for details.
+</details>
+
 
 <details>
   <summary>
     <b>Generate <code>if err != nil {</code> via <a href="https://github.com/koron/iferr">iferr</a></b>
   </summary>
 
+  ![Generate if err != nil {](./vhs/iferr.gif)
+
   Set the cursor on the line with `err` and execute
 
   ```vim
@@ -219,11 +219,78 @@ require("gopher").setup {
   ```
 </details>
 
+## Configuration
+
+> [!IMPORTANT]
+>
+> If you need more info look `:h gopher.nvim`
+
+**Take a look at default options (might be a bit outdated, look `:h gopher.nvim-config`)**
+
+```lua
+require("gopher").setup {
+  -- log level, you might consider using DEBUG or TRACE for debugging the plugin
+  log_level = vim.log.levels.INFO,
+
+  -- timeout for running internal commands
+  timeout = 2000,
+
+  -- timeout for running installer commands(e.g :GoDepsInstall, :GoDepsInstallSync)
+  installer_timeout = 999999,
+
+  -- user specified paths to binaries
+  commands = {
+    go = "go",
+    gomodifytags = "gomodifytags",
+    gotests = "gotests",
+    impl = "impl",
+    iferr = "iferr",
+  },
+  gotests = {
+    -- a default template that gotess will use.
+    -- gotets doesn't have template named `default`, we use it to represent absence of the provided template.
+    template = "default",
+
+    -- path to a directory containing custom test code templates
+    template_dir = nil,
+
+    -- use named tests(map with test name as key) in table tests(slice of structs by default)
+    named = false,
+  },
+  gotag = {
+    transform = "snakecase",
+
+    -- default tags to add to struct fields
+    default_tag = "json",
+
+    -- default tag option added struct fields, set to nil to disable
+    -- e.g: `option = "json=omitempty,xml=omitempty`
+    option = nil,
+  },
+  iferr = {
+    -- choose a custom error message, nil to use default
+    -- e.g: `message = 'fmt.Errorf("failed to %w", err)'`
+    message = nil,
+  },
+  json2go = {
+    -- command used to open interactive input.
+    -- e.g: `split`, `botright split`, `tabnew`
+    interactive_cmd = "vsplit",
+
+    -- name of autogenerated struct
+    -- e.g: "MySuperCoolName"
+    type_name = nil,
+  },
+}
+```
+
+## Troubleshooting
+The most common issue with the plugin is missing dependencies.
+Run `:checkhealth gopher` to verify that the plugin is installed correctly.
+If any binaries are missing, install them using `:GoInstallDeps`.
+
+If the issue persists, feel free to [open a new issue](https://github.com/olexsmir/gopher.nvim/issues/new).
+
 ## Contributing
 
 PRs are always welcome. See [CONTRIBUTING.md](./CONTRIBUTING.md)
-
-## Thanks
-
-- [go.nvim](https://github.com/ray-x/go.nvim)
-- [iferr](https://github.com/koron/iferr)

Taskfile.yml

@@ -1,28 +1,28 @@
 version: "3"
+
+includes:
+  vhs:
+    taskfile: ./vhs/Taskfile.yml
+    dir: ./vhs
+
 tasks:
   lint:
-    desc: runs all linters
-    cmds:
-      - task: selene
-      - stylua --check .
-
-  selene:
-    desc: runs lua linter(selene)
     cmds:
       - selene .
+      - stylua --check .
 
-  stylua:
+  format:
-    desc: runs lua formatter
+    cmd: stylua .
-    cmds:
-      - stylua .
 
-  tests:
+  test:
-    desc: run all tests
     cmds:
       - |
         nvim --clean --headless \
              -u ./scripts/minimal_init.lua \
-             -c "lua MiniTest.run()"
+             -c "lua MiniTest.run()" \
+             -c ":qa!"
+  nvim:
+    cmd: nvim --clean -u "./scripts/minimal_init.lua" {{ .CLI_ARGS }}
 
   docgen:
     desc: generate vimhelp
@@ -32,3 +32,11 @@ tasks:
              -u "./scripts/minimal_init.lua" \
              -c "luafile ./scripts/docgen.lua" \
              -c ":qa!"
+
+  install-deps:
+    desc: installs go bin (used in CI)
+    cmds:
+      - |
+        nvim --clean --headless \
+             -u "./scripts/minimal_init.lua" \
+             +GoInstallDepsSync +qa

doc/gopher.nvim.txt

@@ -13,6 +13,7 @@ Table of Contents
   Config ................................................ |gopher.nvim-config|
   Commands ............................................ |gopher.nvim-commands|
   Modify struct tags ............................... |gopher.nvim-struct-tags|
+  json2go .............................................. |gopher.nvim-json2go|
   Auto implementation of interface methods ................ |gopher.nvim-impl|
   Generating unit tests boilerplate .................... |gopher.nvim-gotests|
   Iferr .................................................. |gopher.nvim-iferr|
@@ -36,11 +37,11 @@ Parameters ~
 ------------------------------------------------------------------------------
                                                       *gopher.nvim-dependencies*
                              `gopher.install_deps`
-Gopher.nvim implements most of its features using third-party tools.
+
-To install these tools, you can run `:GoInstallDeps` command
+Gopher.nvim implements most of its features using third-party tools. To
-or call `require("gopher").install_deps()` if you want to use lua api.
+install plugin's dependencies, you can run:
-By default dependencies will be installed asynchronously,
+`:GoInstallDeps` or `:GoInstallDepsSync`
-to install them synchronously pass `{sync = true}` as an argument.
+or use `require("gopher").install_deps()` if you prefer lua api.
 
 
 ==============================================================================
@@ -57,7 +58,8 @@ to install them synchronously pass `{sync = true}` as an argument.
     ---@type number
     timeout = 2000,
 
-    --- timeout for running installer commands(e.g :GoDepsInstall, :GoDepsInstallSync)
+    -- timeout for running installer commands(e.g :GoDepsInstall, :GoDepsInstallSync)
+    ---@type number
     installer_timeout = 999999,
 
     -- user specified paths to binaries
@@ -68,15 +70,19 @@ to install them synchronously pass `{sync = true}` as an argument.
       gotests = "gotests",
       impl = "impl",
       iferr = "iferr",
+      json2go = "json2go",
     },
     ---@class gopher.ConfigGotests
     gotests = {
-      -- gotests doesn't have template named "default" so this plugin uses "default" to set the default template
+      -- a default template that gotess will use.
+      -- gotets doesn't have template named `default`, we use it to represent absence of the provided template.
       template = "default",
+
       -- path to a directory containing custom test code templates
       ---@type string|nil
       template_dir = nil,
-      -- switch table tests from using slice to map (with test name for the key)
+
+      -- use named tests(map with test name as key) in table tests(slice of structs by default)
       named = false,
     },
     ---@class gopher.ConfigGoTag
@@ -86,16 +92,36 @@ to install them synchronously pass `{sync = true}` as an argument.
 
       -- default tags to add to struct fields
       default_tag = "json",
+
+      -- default tag option added struct fields, set to nil to disable
+      -- e.g: `option = "json=omitempty,xml=omitempty`
+      ---@type string|nil
+      option = nil,
     },
+    ---@class gopher.ConfigIfErr
     iferr = {
-      -- choose a custom error message
+      -- choose a custom error message, nil to use default
+      -- e.g: `message = 'fmt.Errorf("failed to %w", err)'`
       ---@type string|nil
       message = nil,
     },
+    ---@class gopher.ConfigJson2Go
+    json2go = {
+      -- command used to open interactive input.
+      -- e.g: `split`, `botright split`, `tabnew`
+      interactive_cmd = "vsplit",
+
+      -- name of autogenerated struct, if nil none, will the default one of json2go.
+      -- e.g: "MySuperCoolName"
+      ---@type string|nil
+      type_name = nil,
+    },
   }
 <
 Class ~
 {gopher.Config}
+Fields ~
+{setup} `(fun(user_config?: gopher.Config))`
 
 
 ==============================================================================
@@ -110,16 +136,21 @@ you can set `vim.g.gopher_register_commands` to `false`, before loading the plug
 ------------------------------------------------------------------------------
                                                        *gopher.nvim-struct-tags*
 
-`struct_tags` is utilizing the `gomodifytags` tool to add or remove tags to struct fields.
+`struct_tags` is utilizing the `gomodifytags` tool to add or remove tags to
+struct fields.
 
 Usage ~
 
-How to add/remove tags to struct fields:
+How to add/remove/clear tags to struct fields:
 1. Place cursor on the struct
 2. Run `:GoTagAdd json` to add json tags to struct fields
 3. Run `:GoTagRm json` to remove json tags to struct fields
+4. Run `:GoTagClear` to clear all tags from struct fields
+
+If you want to add/remove tag with options, you can use `json=omitempty`
+(where json is tag, and omitempty is its option).
+Example: `:GoTagAdd xml json=omitempty`
 
-To clear all tags from struct run: `:GoTagClear`
 
 NOTE: if you dont specify the tag it will use `json` as default
 
@@ -140,6 +171,42 @@ Example:
    }
 <
 
+==============================================================================
+------------------------------------------------------------------------------
+                                                           *gopher.nvim-json2go*
+
+Convert json to go type annotations.
+
+Usage ~
+
+`:GoJson` opens a temporary buffer where you can paste or write JSON.
+Saving the buffer (`:w` or `:wq`) automatically closes it and inserts the
+generated Go struct into the original buffer at the cursor position.
+
+Alternatively, you can pass JSON directly as an argument:
+>vim
+   :GoJson {"name": "Alice", "age": 30}
+<
+------------------------------------------------------------------------------
+                                                           *json2go.transform()*
+                        `json2go.transform`({json_str})
+
+Parameters ~
+{json_str} `(string)` Json string that is going to be converted to go type.
+Return ~
+`(string)` `(optional)` Go type, or nil if failed.
+
+------------------------------------------------------------------------------
+                                                             *json2go.json2go()*
+                         `json2go.json2go`({json_str})
+Converts json string to go type, and puts result under the cursor. If
+[json_str] is nil, will open an interactive prompt (with cmd set in
+config).
+
+Parameters ~
+{json_str} `(optional)` `(string)`
+
+
 ==============================================================================
 ------------------------------------------------------------------------------
                                                               *gopher.nvim-impl*
@@ -147,6 +214,7 @@ Example:
 Integration of `impl` tool to generate method stubs for interfaces.
 
 Usage ~
+
 1. Automatically implement an interface for a struct:
  - Place your cursor on the struct where you want to implement the interface.
  - Run `:GoImpl io.Reader`
@@ -193,8 +261,9 @@ Usage ~
 - Generate unit tests *only* for *exported(public)* functions/methods:
  - run `:GoTestsExp`
 
-You can also specify the template to use for generating the tests. See |gopher.nvim-config|
+You can also specify the template to use for generating the tests.
-More details about templates can be found at: https://github.com/cweill/gotests
+See |gopher.nvim-config|.
+More details about templates: https://github.com/cweill/gotests
 
 If you prefer named tests, you can enable them in |gopher.nvim-config|.
 
@@ -217,7 +286,9 @@ Execute `:GoIfErr` near any `err` variable to insert the check
 This module provides a way to generate comments for Go code.
 
 Usage ~
-Set cursor on line with function/method/struct/etc and run `:GoCmt` to generate a comment.
+
+Set cursor on line with function/method/struct/etc and
+run `:GoCmt` to generate a comment.
 
 
  vim:tw=78:ts=8:noet:ft=help:norl:

lua/gopher/_utils/gocmd.lua

@@ -1,51 +0,0 @@
-local r = require "gopher._utils.runner"
-local c = require("gopher.config").commands
-local u = require "gopher._utils"
-local gocmd = {}
-
----@param args string[]
----@return string[]
-local function if_get(args)
-  for i, arg in ipairs(args) do
-    local m = string.match(arg, "^https://(.*)$") or string.match(arg, "^http://(.*)$") or arg
-    table.remove(args, i)
-    table.insert(args, i, m)
-  end
-  return args
-end
-
----@param args unknown[]
----@return string[]
-local function if_generate(args)
-  if #args == 1 and args[1] == "%" then
-    args[1] = vim.fn.expand "%"
-  end
-  return args
-end
-
----@param subcmd string
----@param args string[]
----@return string
-function gocmd.run(subcmd, args)
-  if #args == 0 and subcmd ~= "generate" then
-    error "please provide any arguments"
-  end
-
-  if subcmd == "get" then
-    args = if_get(args)
-  end
-
-  if subcmd == "generate" then
-    args = if_generate(args)
-  end
-
-  local rs = r.sync { c.go, subcmd, unpack(args) }
-  if rs.code ~= 0 then
-    error("go " .. subcmd .. " failed: " .. rs.stderr)
-  end
-
-  u.notify(c.go .. " " .. subcmd .. " ran successful")
-  return rs.stdout
-end
-
-return gocmd

lua/gopher/_utils/init.lua

@@ -3,7 +3,7 @@ local log = require "gopher._utils.log"
 local utils = {}
 
 ---@param msg string
----@param lvl? number by default `vim.log.levels.INFO`
+---@param lvl? integer by default `vim.log.levels.INFO`
 function utils.notify(msg, lvl)
   lvl = lvl or vim.log.levels.INFO
   vim.notify(msg, lvl, {
@@ -38,4 +38,35 @@ function utils.trimend(s)
   return r
 end
 
+-- Since indentation can be spaces or tabs, that's my hack around it
+---@param line string
+---@param indent integer
+---@return string
+function utils.indent(line, indent)
+  local char = string.sub(line, 1, 1)
+  if char ~= " " and char ~= "\t" then
+    char = " "
+  end
+  return string.rep(char, indent)
+end
+
+---@generic T
+---@param tbl T[]
+---@return T[]
+function utils.list_unique(tbl)
+  if vim.fn.has "nvim-0.12" == 1 then
+    return vim.list.unique(tbl)
+  end
+
+  for i = #tbl, 1, -1 do
+    for j = 1, i - 1 do
+      if tbl[i] == tbl[j] then
+        table.remove(tbl, i)
+        break
+      end
+    end
+  end
+  return tbl
+end
+
 return utils

lua/gopher/_utils/log.lua

@@ -3,7 +3,7 @@
 -- for the code i have stolen(or have inspected by idk)
 local c = require "gopher.config"
 
----@class Gopher.Logger
+---@class gopher.Logger
 ---@field get_outfile fun():string
 ---@field trace fun(...)
 ---@field fmt_trace fun(...)
@@ -44,7 +44,7 @@ local config = {
   float_precision = 0.01,
 }
 
----@type Gopher.Logger
+---@type gopher.Logger
 ---@diagnostic disable-next-line: missing-fields
 local log = {}
 

lua/gopher/_utils/ts.lua

@@ -11,9 +11,13 @@ local queries = {
        right: (expression_list (composite_literal
                                  type: (struct_type))))]
   ]],
+  struct_field = [[
+    (field_declaration name: (field_identifier) @_name)
+  ]],
   func = [[
     [(function_declaration name: (identifier)       @_name)
-     (method_declaration   name: (field_identifier) @_name)]
+     (method_declaration   name: (field_identifier) @_name)
+     (method_elem          name: (field_identifier) @_name)]
   ]],
   package = [[
     (package_identifier) @_name
@@ -23,12 +27,17 @@ local queries = {
       name: (type_identifier) @_name
       type: (interface_type))
   ]],
+  var = [[
+    [(var_declaration (var_spec name: (identifier) @_name))
+     (short_var_declaration
+       left: (expression_list (identifier) @_name @_var))]
+  ]],
 }
 
 ---@param parent_type string[]
 ---@param node TSNode
 ---@return TSNode?
-local function get_parrent_node(parent_type, node)
+local function get_parent_node(parent_type, node)
   ---@type TSNode?
   local current = node
   while current do
@@ -64,10 +73,11 @@ local function get_captures(query, node, bufnr)
 end
 
 ---@class gopher.TsResult
----@field name string
+---@field name string Name of the struct, function, etc
----@field start_line integer
+---@field start integer Line number where the declaration starts
----@field end_line integer
+---@field end_ integer Line number where the declaration ends
----@field is_varstruct boolean
+---@field indent integer Number of spaces/tabs in the current cursor line
+---@field is_varstruct boolean Is struct declared as `var S struct{}` or `s := struct{}{}`
 
 ---@param bufnr integer
 ---@param parent_type string[]
@@ -78,25 +88,24 @@ local function do_stuff(bufnr, parent_type, query)
     error "No treesitter parser found for go"
   end
 
-  local node = vim.treesitter.get_node {
+  local node = vim.treesitter.get_node { bufnr = bufnr }
-    bufnr = bufnr,
-  }
   if not node then
-    error "No nodes found under cursor"
+    error "No nodes found under the cursor"
   end
 
-  local parent_node = get_parrent_node(parent_type, node)
+  local parent_node = get_parent_node(parent_type, node)
   if not parent_node then
-    error "No parent node found under cursor"
+    error "No parent node found under the cursor"
   end
 
   local q = vim.treesitter.query.parse("go", query)
   local res = get_captures(q, parent_node, bufnr)
   assert(res.name ~= nil, "No capture name found")
 
-  local start_row, _, end_row, _ = parent_node:range()
+  local start_row, start_col, end_row, _ = parent_node:range()
-  res["start_line"] = start_row + 1
+  res["indent"] = start_col
-  res["end_line"] = end_row + 1
+  res["start"] = start_row + 1
+  res["end_"] = end_row + 1
 
   return res
 end
@@ -104,11 +113,12 @@ end
 ---@param bufnr integer
 function ts.get_struct_under_cursor(bufnr)
   --- should be both type_spec and type_declaration
-  --- because in cases like `type ( T struct{}, U strict{} )`
+  --- because in cases like `type ( T struct{}, U struct{} )`
-  --- i will be choosing always last struct in the list
   ---
   --- var_declaration is for cases like `var x struct{}`
   --- short_var_declaration is for cases like `x := struct{}{}`
+  ---
+  --- it always chooses last struct type in the list
   return do_stuff(bufnr, {
     "type_spec",
     "type_declaration",
@@ -117,10 +127,19 @@ function ts.get_struct_under_cursor(bufnr)
   }, queries.struct)
 end
 
+---@param bufnr integer
+function ts.get_struct_field_under_cursor(bufnr)
+  return do_stuff(bufnr, { "field_declaration" }, queries.struct_field)
+end
+
 ---@param bufnr integer
 function ts.get_func_under_cursor(bufnr)
   --- since this handles both and funcs and methods we should check for both parent nodes
-  return do_stuff(bufnr, { "function_declaration", "method_declaration" }, queries.func)
+  return do_stuff(bufnr, {
+    "method_elem",
+    "function_declaration",
+    "method_declaration",
+  }, queries.func)
 end
 
 ---@param bufnr integer
@@ -133,4 +152,9 @@ function ts.get_interface_under_cursor(bufnr)
   return do_stuff(bufnr, { "type_declaration" }, queries.interface)
 end
 
+---@param bufnr integer
+function ts.get_variable_under_cursor(bufnr)
+  return do_stuff(bufnr, { "var_declaration", "short_var_declaration" }, queries.var)
+end
+
 return ts

lua/gopher/comment.lua

@@ -3,36 +3,46 @@
 ---@text
 --- This module provides a way to generate comments for Go code.
 ---
----@usage Set cursor on line with function/method/struct/etc and run `:GoCmt` to generate a comment.
+---@usage
+--- Set cursor on line with function/method/struct/etc and
+--- run `:GoCmt` to generate a comment.
 
 local ts = require "gopher._utils.ts"
 local log = require "gopher._utils.log"
+local u = require "gopher._utils"
 local comment = {}
 
----@param name string
+--- NOTE: The order of functions executed inside this function is IMPORTANT.
+--- This function is extremely fragile; run tests after making any changes.
+---
+---@param bufnr integer
+---@param line string
 ---@return string
 ---@dochide
-local function template(name)
+local function generate(bufnr, line)
-  return "// " .. name .. " "
+  local sf_ok, sf_res = pcall(ts.get_struct_field_under_cursor, bufnr)
+  if sf_ok then
+    return u.indent(line, sf_res.indent) .. "// " .. sf_res.name .. " "
   end
 
----@param bufnr integer
----@return string
----@dochide
-local function generate(bufnr)
   local s_ok, s_res = pcall(ts.get_struct_under_cursor, bufnr)
   if s_ok then
-    return template(s_res.name)
+    return u.indent(line, s_res.indent) .. "// " .. s_res.name .. " "
+  end
+
+  local v_ok, v_res = pcall(ts.get_variable_under_cursor, bufnr)
+  if v_ok then
+    return u.indent(line, v_res.indent) .. "// " .. v_res.name .. " "
   end
 
   local f_ok, f_res = pcall(ts.get_func_under_cursor, bufnr)
   if f_ok then
-    return template(f_res.name)
+    return u.indent(line, f_res.indent) .. "// " .. f_res.name .. " "
   end
 
   local i_ok, i_res = pcall(ts.get_interface_under_cursor, bufnr)
   if i_ok then
-    return template(i_res.name)
+    return u.indent(line, i_res.indent) .. "// " .. i_res.name .. " "
   end
 
   local p_ok, p_res = pcall(ts.get_package_under_cursor, bufnr)
@@ -45,12 +55,16 @@ end
 
 function comment.comment()
   local bufnr = vim.api.nvim_get_current_buf()
-  local cmt = generate(bufnr)
+  local lnum = vim.fn.getcurpos()[2]
-  log.debug("generated comment: " .. cmt)
+  local line = vim.fn.getline(lnum)
+  local cmt = generate(bufnr, line)
+  log.debug("generated comment:", {
+    comment = cmt,
+    line = line,
+  })
 
-  local pos = vim.fn.getcurpos()[2]
+  vim.fn.append(lnum - 1, cmt)
-  vim.fn.append(pos - 1, cmt)
+  vim.fn.setpos(".", { bufnr, lnum, #cmt })
-  vim.fn.setpos(".", { 0, pos, #cmt })
   vim.cmd "startinsert!"
 end
 

lua/gopher/config.lua

@@ -1,3 +1,6 @@
+---@type gopher.Config
+---@dochide
+---@diagnostic disable-next-line: missing-fields .setup() gets injected later
 local config = {}
 
 ---@tag gopher.nvim-config.ConfigGoTagTransform
@@ -16,6 +19,7 @@ local config = {}
 ---@tag gopher.nvim-config
 ---@eval return MiniDoc.afterlines_to_code(MiniDoc.current.eval_section)
 ---@class gopher.Config
+---@field setup fun(user_config?: gopher.Config)
 local default_config = {
   -- log level, you might consider using DEBUG or TRACE for debugging the plugin
   ---@type number
@@ -25,7 +29,8 @@ local default_config = {
   ---@type number
   timeout = 2000,
 
-  --- timeout for running installer commands(e.g :GoDepsInstall, :GoDepsInstallSync)
+  -- timeout for running installer commands(e.g :GoDepsInstall, :GoDepsInstallSync)
+  ---@type number
   installer_timeout = 999999,
 
   -- user specified paths to binaries
@@ -36,15 +41,19 @@ local default_config = {
     gotests = "gotests",
     impl = "impl",
     iferr = "iferr",
+    json2go = "json2go",
   },
   ---@class gopher.ConfigGotests
   gotests = {
-    -- gotests doesn't have template named "default" so this plugin uses "default" to set the default template
+    -- a default template that gotess will use.
+    -- gotets doesn't have template named `default`, we use it to represent absence of the provided template.
     template = "default",
+
     -- path to a directory containing custom test code templates
     ---@type string|nil
     template_dir = nil,
-    -- switch table tests from using slice to map (with test name for the key)
+
+    -- use named tests(map with test name as key) in table tests(slice of structs by default)
     named = false,
   },
   ---@class gopher.ConfigGoTag
@@ -54,12 +63,30 @@ local default_config = {
 
     -- default tags to add to struct fields
     default_tag = "json",
+
+    -- default tag option added struct fields, set to nil to disable
+    -- e.g: `option = "json=omitempty,xml=omitempty`
+    ---@type string|nil
+    option = nil,
   },
+  ---@class gopher.ConfigIfErr
   iferr = {
-    -- choose a custom error message
+    -- choose a custom error message, nil to use default
+    -- e.g: `message = 'fmt.Errorf("failed to %w", err)'`
     ---@type string|nil
     message = nil,
   },
+  ---@class gopher.ConfigJson2Go
+  json2go = {
+    -- command used to open interactive input.
+    -- e.g: `split`, `botright split`, `tabnew`
+    interactive_cmd = "vsplit",
+
+    -- name of autogenerated struct, if nil none, will the default one of json2go.
+    -- e.g: "MySuperCoolName"
+    ---@type string|nil
+    type_name = nil,
+  },
 }
 --minidoc_afterlines_end
 
@@ -77,30 +104,32 @@ _config.___plugin_name = "gopher.nvim" ---@diagnostic disable-line: inject-field
 ---@param user_config? gopher.Config
 ---@dochide
 function config.setup(user_config)
-  vim.validate { user_config = { user_config, "table", true } }
+  vim.validate("user_config", user_config, "table", true)
 
   _config = vim.tbl_deep_extend("force", vim.deepcopy(default_config), user_config or {})
 
-  vim.validate {
+  vim.validate("log_level", _config.log_level, "number")
-    log_level = { _config.log_level, "number" },
+  vim.validate("timeout", _config.timeout, "number")
-    timeout = { _config.timeout, "number" },
+  vim.validate("installer_timeout", _config.timeout, "number")
-    installer_timeout = { _config.installer_timeout, "number" },
+  vim.validate("commands", _config.commands, "table")
-    ["commands"] = { _config.commands, "table" },
+  vim.validate("commands.go", _config.commands.go, "string")
-    ["commands.go"] = { _config.commands.go, "string" },
+  vim.validate("commands.gomodifytags", _config.commands.gomodifytags, "string")
-    ["commands.gomodifytags"] = { _config.commands.gomodifytags, "string" },
+  vim.validate("commands.gotests", _config.commands.gotests, "string")
-    ["commands.gotests"] = { _config.commands.gotests, "string" },
+  vim.validate("commands.impl", _config.commands.impl, "string")
-    ["commands.impl"] = { _config.commands.impl, "string" },
+  vim.validate("commands.iferr", _config.commands.iferr, "string")
-    ["commands.iferr"] = { _config.commands.iferr, "string" },
+  vim.validate("commands.json2go", _config.commands.json2go, "string")
-    ["gotests"] = { _config.gotests, "table" },
+  vim.validate("gotests", _config.gotests, "table")
-    ["gotests.template"] = { _config.gotests.template, "string" },
+  vim.validate("gotests.template", _config.gotests.template, "string")
-    ["gotests.template_dir"] = { _config.gotests.template, "string", true },
+  vim.validate("gotests.template_dir", _config.gotests.template_dir, { "string", "nil" })
-    ["gotests.named"] = { _config.gotests.named, "boolean" },
+  vim.validate("gotests.named", _config.gotests.named, "boolean")
-    ["gotag"] = { _config.gotag, "table" },
+  vim.validate("gotag", _config.gotag, "table")
-    ["gotag.transform"] = { _config.gotag.transform, "string" },
+  vim.validate("gotag.transform", _config.gotag.transform, "string")
-    ["gotag.default_tag"] = { _config.gotag.default_tag, "string" },
+  vim.validate("gotag.default_tag", _config.gotag.default_tag, "string")
-    ["iferr"] = { _config.iferr, "table" },
+  vim.validate("gotag.option", _config.gotag.option, { "string", "nil" })
-    ["iferr.message"] = { _config.iferr.message, "string", true },
+  vim.validate("iferr", _config.iferr, "table")
-  }
+  vim.validate("iferr.message", _config.iferr.message, { "string", "nil" })
+  vim.validate("json2go.installer_timeout", _config.json2go.interactive_cmd, "string")
+  vim.validate("json2go.type_name", _config.json2go.type_name, { "string", "nil" })
 end
 
 setmetatable(config, {
@@ -110,5 +139,4 @@ setmetatable(config, {
 })
 
 ---@dochide
----@return gopher.Config
 return config

lua/gopher/go.lua

@@ -0,0 +1,56 @@
+local c = require "gopher.config"
+local u = require "gopher._utils"
+local r = require "gopher._utils.runner"
+local go = {}
+
+local function run(subcmd, args)
+  local rs = r.sync { c.commands.go, subcmd, unpack(args) }
+  if rs.code ~= 0 then
+    error("go " .. subcmd .. " failed: " .. rs.stderr)
+  end
+
+  u.notify(c.commands.go .. " " .. subcmd .. " ran successful")
+  return rs.stdout
+end
+
+---@param args string[]
+function go.get(args)
+  for i, arg in ipairs(args) do
+    local m = string.match(arg, "^https://(.*)$") or string.match(arg, "^http://(.*)$") or arg
+    table.remove(args, i)
+    table.insert(args, i, m)
+  end
+
+  run("get", args)
+end
+
+---@param args string[]
+function go.mod(args)
+  run("mod", args)
+end
+
+---@param args string[]
+function go.work(args)
+  -- TODO: use `gopls.tidy`
+
+  run("work", args)
+end
+
+---Executes `go generate`
+---If only argument is `%` it's going to be equivalent to `go generate <path to current file>`
+---@param args string[]
+function go.generate(args)
+  -- TODO: use `gopls.generate`
+
+  if #args == 0 then
+    error "please provide arguments"
+  end
+
+  if #args == 1 and args[1] == "%" then
+    args[1] = vim.fn.expand "%"
+  end
+
+  run("generate", args)
+end
+
+return go

lua/gopher/gotests.lua

@@ -12,8 +12,9 @@
 --- - Generate unit tests *only* for *exported(public)* functions/methods:
 ---  - run `:GoTestsExp`
 ---
---- You can also specify the template to use for generating the tests. See |gopher.nvim-config|
+--- You can also specify the template to use for generating the tests.
---- More details about templates can be found at: https://github.com/cweill/gotests
+--- See |gopher.nvim-config|.
+--- More details about templates: https://github.com/cweill/gotests
 ---
 --- If you prefer named tests, you can enable them in |gopher.nvim-config|.
 

lua/gopher/health.lua

@@ -1,62 +1,58 @@
+local c = require("gopher.config").commands
 local health = {}
-local cmd = require("gopher.config").commands
 
 local deps = {
+  vim_version = "nvim-0.10",
   bin = {
     {
-      bin = cmd.go,
+      bin = c.go,
       msg = "required for `:GoGet`, `:GoMod`, `:GoGenerate`, `:GoWork`, `:GoInstallDeps`, `:GoInstallDepsSync`",
-      optional = false,
-    },
-    { bin = cmd.gomodifytags, msg = "required for `:GoTagAdd`, `:GoTagRm`", optional = true },
-    { bin = cmd.impl, msg = "required for `:GoImpl`", optional = true },
-    { bin = cmd.iferr, msg = "required for `:GoIfErr`", optional = true },
-    {
-      bin = cmd.gotests,
-      msg = "required for `:GoTestAdd`, `:GoTestsAll`, `:GoTestsExp`",
-      optional = true,
     },
+    { bin = c.gomodifytags, msg = "required for `:GoTagAdd`, `:GoTagRm`" },
+    { bin = c.impl, msg = "required for `:GoImpl`" },
+    { bin = c.iferr, msg = "required for `:GoIfErr`" },
+    { bin = c.gotests, msg = "required for `:GoTestAdd`, `:GoTestsAll`, `:GoTestsExp`" },
   },
   treesitter = {
     { parser = "go", msg = "required for most of the parts of `gopher.nvim`" },
   },
 }
 
----@param bin string
+---@param bin {bin:string, msg:string, optional:boolean}
----@return boolean
+local function check_binary(bin)
-local function is_binary_found(bin)
+  if vim.fn.executable(bin.bin) == 1 then
-  return vim.fn.executable(bin) == 1
+    vim.health.ok(bin.bin .. " is found oh PATH: `" .. vim.fn.exepath(bin.bin) .. "`")
+  else
+    vim.health.error(bin.bin .. " not found on PATH, " .. bin.msg)
+  end
 end
 
----@param ft string
+---@param ts {parser:string, msg:string}
----@return boolean
+local function check_treesitter(ts)
-local function is_treesitter_parser_available(ft)
+  local ok, parser = pcall(vim.treesitter.get_parser, 0, ts.parser)
-  local ok, parser = pcall(vim.treesitter.get_parser, 0, ft)
+  if ok and parser ~= nil then
-  return ok and parser ~= nil
+    vim.health.ok("`" .. ts.parser .. "` parser is installed")
+  else
+    vim.health.error("`" .. ts.parser .. "` parser not found")
+  end
 end
 
 function health.check()
-  vim.health.start "required binaries"
+  vim.health.start "Neovim version"
-  vim.health.info "all those binaries can be installed by `:GoInstallDeps`"
+  if vim.fn.has(deps.vim_version) == 1 then
-  for _, bin in ipairs(deps.bin) do
+    vim.health.ok "Neovim version is compatible"
-    if is_binary_found(bin.bin) then
-      vim.health.ok(bin.bin .. " installed")
   else
-      if bin.optional then
+    vim.health.error(deps.vim_version .. " or newer is required")
-        vim.health.warn(bin.bin .. " not found, " .. bin.msg)
-      else
-        vim.health.error(bin.bin .. " not found, " .. bin.msg)
-      end
-    end
   end
 
-  vim.health.start "required treesitter parsers"
+  vim.health.start "Required binaries (those can be installed with `:GoInstallDeps`)"
-  for _, parser in ipairs(deps.treesitter) do
+  for _, bin in ipairs(deps.bin) do
-    if is_treesitter_parser_available(parser.parser) then
+    check_binary(bin)
-      vim.health.ok(parser.parser .. " parser installed")
-    else
-      vim.health.error(parser.parser .. " parser not found, " .. parser.msg)
   end
+
+  vim.health.start "Treesitter"
+  for _, parser in ipairs(deps.treesitter) do
+    check_treesitter(parser)
   end
 end
 

lua/gopher/iferr.lua

@@ -42,7 +42,7 @@ function iferr.iferr()
 
   vim.fn.append(pos, u.remove_empty_lines(vim.split(rs.stdout, "\n")))
   vim.cmd [[silent normal! j=2j]]
-  vim.fn.setpos(".", pos)
+  vim.fn.setpos(".", pos --[[@as integer[] ]])
 end
 
 return iferr

lua/gopher/impl.lua

@@ -3,7 +3,8 @@
 ---@text
 --- Integration of `impl` tool to generate method stubs for interfaces.
 ---
----@usage 1. Automatically implement an interface for a struct:
+---@usage
+--- 1. Automatically implement an interface for a struct:
 ---  - Place your cursor on the struct where you want to implement the interface.
 ---  - Run `:GoImpl io.Reader`
 ---  - This will automatically determine the receiver and implement the `io.Reader` interface.

lua/gopher/init.lua

@@ -13,7 +13,7 @@
 local log = require "gopher._utils.log"
 local tags = require "gopher.struct_tags"
 local tests = require "gopher.gotests"
-local gocmd = require("gopher._utils.gocmd").run
+local go = require "gopher.go"
 local gopher = {}
 
 ---@toc_entry Setup
@@ -35,11 +35,11 @@ end
 
 ---@toc_entry Install dependencies
 ---@tag gopher.nvim-dependencies
----@text Gopher.nvim implements most of its features using third-party tools.
+---@text
---- To install these tools, you can run `:GoInstallDeps` command
+--- Gopher.nvim implements most of its features using third-party tools. To
---- or call `require("gopher").install_deps()` if you want to use lua api.
+--- install plugin's dependencies, you can run:
---- By default dependencies will be installed asynchronously,
+--- `:GoInstallDeps` or `:GoInstallDepsSync`
---- to install them synchronously pass `{sync = true}` as an argument.
+--- or use `require("gopher").install_deps()` if you prefer lua api.
 gopher.install_deps = require("gopher.installer").install_deps
 
 gopher.impl = require("gopher.impl").impl
@@ -58,20 +58,9 @@ gopher.test = {
   all = tests.all_tests,
 }
 
-gopher.get = function(...)
+gopher.get = go.get
-  gocmd("get", ...)
+gopher.mod = go.mod
-end
+gopher.work = go.work
-
+gopher.generate = go.generate
-gopher.mod = function(...)
-  gocmd("mod", ...)
-end
-
-gopher.generate = function(...)
-  gocmd("generate", ...)
-end
-
-gopher.work = function(...)
-  gocmd("work", ...)
-end
 
 return gopher

lua/gopher/installer.lua

@@ -9,6 +9,7 @@ local urls = {
   impl = "github.com/josharian/impl@latest",
   gotests = "github.com/cweill/gotests/...@develop",
   iferr = "github.com/koron/iferr@latest",
+  json2go = "olexsmir.xyz/json2go/cmd/json2go@latest",
 }
 
 ---@param opt vim.SystemCompleted

lua/gopher/json2go.lua

@@ -0,0 +1,137 @@
+---@toc_entry json2go
+---@tag gopher.nvim-json2go
+---@text
+--- Convert json to go type annotations.
+---
+---@usage
+--- `:GoJson` opens a temporary buffer where you can paste or write JSON.
+--- Saving the buffer (`:w` or `:wq`) automatically closes it and inserts the
+--- generated Go struct into the original buffer at the cursor position.
+---
+--- Alternatively, you can pass JSON directly as an argument:
+--- >vim
+---    :GoJson {"name": "Alice", "age": 30}
+--- <
+
+local c = require "gopher.config"
+local log = require "gopher._utils.log"
+local u = require "gopher._utils"
+local r = require "gopher._utils.runner"
+local json2go = {}
+
+---@dochide
+---@param bufnr integer
+---@param cpos integer
+---@param type_ string
+local function apply(bufnr, cpos, type_)
+  local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
+  local input_lines = u.remove_empty_lines(vim.split(type_, "\n"))
+  for i, line in pairs(input_lines) do
+    table.insert(lines, cpos + i, line)
+  end
+  vim.api.nvim_buf_set_lines(bufnr, 0, -1, true, lines)
+end
+
+-- Convert json string to go type.
+---
+---@param json_str string Json string that is going to be converted to go type.
+---@return string? Go type, or nil if failed.
+function json2go.transform(json_str)
+  local cmd = { c.commands.json2go }
+  if c.json2go.type_name then
+    table.insert(cmd, "-type", c.json2go.type_name)
+  end
+
+  local rs = r.sync(cmd, { stdin = json_str })
+  if rs.code ~= 0 then
+    u.notify("json2go: got this error: " .. rs.stdout, vim.log.levels.ERROR)
+    log.error("json2go: got this error: " .. rs.stdout)
+    return
+  end
+  return rs.stdout
+end
+
+---@dochide
+---@param ocpos integer
+local function interactive(ocpos)
+  local obuf = vim.api.nvim_get_current_buf()
+  local owin = vim.api.nvim_get_current_win()
+
+  -- setup the input window
+  local buf = vim.api.nvim_create_buf(false, true)
+  vim.cmd(c.json2go.interactive_cmd)
+
+  local win = vim.api.nvim_get_current_win()
+  vim.api.nvim_win_set_buf(win, buf)
+  vim.api.nvim_buf_set_name(buf, "[GoJson input]")
+  vim.api.nvim_set_option_value("filetype", "jsonc", { buf = buf })
+  vim.api.nvim_set_option_value("buftype", "acwrite", { buf = buf })
+  vim.api.nvim_set_option_value("swapfile", false, { buf = buf })
+  vim.api.nvim_set_option_value("bufhidden", "delete", { buf = buf })
+  vim.api.nvim_buf_set_lines(buf, 0, -1, false, {
+    "// Write your json here.",
+    "// Writing and quitting (:wq), will generate go struct under the cursor.",
+    "",
+    "",
+  })
+
+  vim.api.nvim_create_autocmd("BufLeave", { buffer = buf, command = "stopinsert" })
+  vim.api.nvim_create_autocmd("BufWriteCmd", {
+    buffer = buf,
+    once = true,
+    callback = function()
+      local input = vim.api.nvim_buf_get_lines(buf, 0, -1, true)
+      local inp = table.concat(
+        vim
+          .iter(input)
+          :filter(function(line)
+            local found = string.find(line, "^//.*")
+            return (not found) or (line == "")
+          end)
+          :totable(),
+        "\n"
+      )
+
+      local go_type = json2go.transform(inp)
+      if not go_type then
+        error "cound't convert json to go type"
+      end
+
+      vim.api.nvim_set_option_value("modified", false, { buf = buf })
+      apply(obuf, ocpos, go_type)
+
+      vim.api.nvim_set_current_win(owin)
+      vim.api.nvim_win_set_cursor(owin, { ocpos + 1, 0 })
+
+      vim.schedule(function()
+        pcall(vim.api.nvim_win_close, win, true)
+        pcall(vim.api.nvim_buf_delete, buf, {})
+      end)
+    end,
+  })
+
+  vim.cmd "normal! G"
+  vim.cmd "startinsert"
+end
+
+--- Converts json string to go type, and puts result under the cursor. If
+--- [json_str] is nil, will open an interactive prompt (with cmd set in
+--- config).
+---
+---@param json_str? string
+function json2go.json2go(json_str)
+  local cur_line = vim.api.nvim_win_get_cursor(0)[1]
+  if not json_str then
+    interactive(cur_line)
+    return
+  end
+
+  local go_type = json2go.transform(json_str)
+  if not go_type then
+    error "cound't convert json to go type"
+  end
+
+  apply(0, cur_line, go_type)
+end
+
+return json2go

lua/gopher/struct_tags.lua

@@ -1,15 +1,20 @@
 ---@toc_entry Modify struct tags
 ---@tag gopher.nvim-struct-tags
 ---@text
---- `struct_tags` is utilizing the `gomodifytags` tool to add or remove tags to struct fields.
+--- `struct_tags` is utilizing the `gomodifytags` tool to add or remove tags to
+--- struct fields.
 ---
 ---@usage
---- How to add/remove tags to struct fields:
+--- How to add/remove/clear tags to struct fields:
 --- 1. Place cursor on the struct
 --- 2. Run `:GoTagAdd json` to add json tags to struct fields
 --- 3. Run `:GoTagRm json` to remove json tags to struct fields
+--- 4. Run `:GoTagClear` to clear all tags from struct fields
+---
+--- If you want to add/remove tag with options, you can use `json=omitempty`
+--- (where json is tag, and omitempty is its option).
+--- Example: `:GoTagAdd xml json=omitempty`
 ---
---- To clear all tags from struct run: `:GoTagClear`
 ---
 --- NOTE: if you dont specify the tag it will use `json` as default
 ---
@@ -37,11 +42,22 @@ local u = require "gopher._utils"
 local log = require "gopher._utils.log"
 local struct_tags = {}
 
+---@dochide
+---@class gopher.StructTagInput
+---@field input string[] User provided tags
+---@field range? gopher.StructTagRange  (optional)
+
+---@dochide
+---@class gopher.StructTagRange
+---@field start number
+---@field end_ number
+
 ---@param fpath string
 ---@param bufnr integer
+---@param range? gopher.StructTagRange
 ---@param user_args string[]
 ---@dochide
-local function handle_tags(fpath, bufnr, user_args)
+local function handle_tags(fpath, bufnr, range, user_args)
   local st = ts.get_struct_under_cursor(bufnr)
 
   -- stylua: ignore
@@ -53,9 +69,10 @@ local function handle_tags(fpath, bufnr, user_args)
     "-w",
   }
 
-  if st.is_varstruct then
+  -- `-struct` and `-line` cannot be combined, setting them separately
+  if range or st.is_varstruct then
     table.insert(cmd, "-line")
-    table.insert(cmd, string.format("%d,%d", st.start_line, st.end_line))
+    table.insert(cmd, string.format("%d,%d", (range or st).start, (range or st).end_))
   else
     table.insert(cmd, "-struct")
     table.insert(cmd, st.name)
@@ -90,49 +107,94 @@ local function handle_tags(fpath, bufnr, user_args)
   )
 end
 
+---@dochide
+---@param option string
+local function option_to_tag(option)
+  return option:match "^(.-)="
+end
+
+---@dochide
 ---@param args string[]
----@return string
+local function unwrap_if_needed(args)
----@dochide
+  local out = {}
-local function handler_user_args(args)
+  for _, v in pairs(args) do
-  if #args == 0 then
+    for _, p in pairs(vim.split(v, ",")) do
-    return c.gotag.default_tag
+      table.insert(out, p)
     end
-  return table.concat(args, ",")
+  end
+  return out
 end
 
--- Adds tags to a struct under the cursor
--- See |gopher.nvim-struct-tags|
----@param ... string Tags to add to the struct fields. If not provided, it will use [config.gotag.default_tag]
 ---@dochide
-function struct_tags.add(...)
+---@class gopher.StructTagsArgs
-  local args = { ... }
+---@field tags string
+---@field options string
+
+---@dochide
+---@param args string[]
+---@return gopher.StructTagsArgs
+function struct_tags.parse_args(args)
+  args = unwrap_if_needed(args)
+
+  local tags, options = {}, {}
+  for _, v in pairs(args) do
+    if string.find(v, "=") then
+      table.insert(options, v)
+      table.insert(tags, option_to_tag(v))
+    else
+      table.insert(tags, v)
+    end
+  end
+
+  return {
+    tags = table.concat(u.list_unique(tags), ","),
+    options = table.concat(u.list_unique(options), ","),
+  }
+end
+
+-- Adds tags to a struct under the cursor. See `:h gopher.nvim-struct-tags`.
+---@param opts gopher.StructTagInput
+---@dochide
+function struct_tags.add(opts)
+  log.debug("adding tags", opts)
+
   local fpath = vim.fn.expand "%"
   local bufnr = vim.api.nvim_get_current_buf()
 
-  local user_tags = handler_user_args(args)
+  local user_args = struct_tags.parse_args(opts.input)
-  handle_tags(fpath, bufnr, { "-add-tags", user_tags })
+  handle_tags(fpath, bufnr, opts.range, {
+    "-add-tags",
+    (user_args.tags ~= "") and user_args.tags or c.gotag.default_tag,
+    (user_args.options ~= "" or c.gotag.option) and "-add-options" or nil,
+    (user_args.options ~= "") and user_args.options or c.gotag.option,
+  })
 end
 
--- Removes tags from a struct under the cursor
+-- Removes tags from a struct under the cursor. See `:h gopher.nvim-struct-tags`.
--- See `:h gopher.nvim-struct-tags`
 ---@dochide
----@param ... string Tags to add to the struct fields. If not provided, it will use [config.gotag.default_tag]
+---@param opts gopher.StructTagInput
-function struct_tags.remove(...)
+function struct_tags.remove(opts)
-  local args = { ... }
+  log.debug("removing tags", opts)
+
   local fpath = vim.fn.expand "%"
   local bufnr = vim.api.nvim_get_current_buf()
 
-  local user_tags = handler_user_args(args)
+  local user_args = struct_tags.parse_args(opts.input)
-  handle_tags(fpath, bufnr, { "-remove-tags", user_tags })
+  handle_tags(fpath, bufnr, opts.range, {
+    "-remove-tags",
+    (user_args.tags ~= "") and user_args.tags or c.gotag.default_tag,
+    (user_args.options ~= "" or c.gotag.option ~= nil) and "-remove-options" or nil,
+    (user_args.options ~= "") and user_args.options or c.gotag.option,
+  })
 end
 
--- Removes all tags from a struct under the cursor
+-- Removes all tags from a struct under the cursor.
--- See `:h gopher.nvim-struct-tags`
+-- See `:h gopher.nvim-struct-tags`.
 ---@dochide
 function struct_tags.clear()
   local fpath = vim.fn.expand "%"
   local bufnr = vim.api.nvim_get_current_buf()
-  handle_tags(fpath, bufnr, { "-clear-tags" })
+  handle_tags(fpath, bufnr, nil, { "-clear-tags" })
 end
 
 return struct_tags

nvim.toml

@@ -3,43 +3,3 @@ any = true
 
 [MiniTest]
 any = true
-
-[describe]
-any = true
-[[describe.args]]
-type = "string"
-[[describe.args]]
-type = "function"
-
-[it]
-any = true
-[[it.args]]
-type = "string"
-[[it.args]]
-type = "function"
-
-[before_each]
-any = true
-[[before_each.args]]
-type = "function"
-[[after_each.args]]
-type = "function"
-
-[assert]
-any = true
-
-[assert.is_not]
-any = true
-
-[[assert.equals.args]]
-type = "any"
-[[assert.equals.args]]
-type = "any"
-[[assert.equals.args]]
-type = "any"
-required = false
-
-[[assert.same.args]]
-type = "any"
-[[assert.same.args]]
-type = "any"

plugin/gopher.lua

@@ -11,10 +11,13 @@ end
 ---@param name string
 ---@param fn fun(args: table)
 ---@param nargs? number|"*"|"?"
+---@param range? boolean
 ---@private
-local function cmd(name, fn, nargs)
+local function cmd(name, fn, nargs, range)
-  nargs = nargs or 0
+  vim.api.nvim_create_user_command(name, fn, {
-  vim.api.nvim_create_user_command(name, fn, { nargs = nargs })
+    nargs = nargs or 0,
+    range = range or false,
+  })
 end
 
 cmd("GopherLog", function()
@@ -44,17 +47,35 @@ end)
 
 -- :GoTag
 cmd("GoTagAdd", function(opts)
-  require("gopher").tags.add(unpack(opts.fargs))
+  require("gopher").tags.add {
-end, "*")
+    input = opts.fargs,
+    range = (opts.count ~= -1) and {
+      start = opts.line1,
+      end_ = opts.line2,
+    } or nil,
+  }
+end, "*", true)
 
 cmd("GoTagRm", function(opts)
-  require("gopher").tags.rm(unpack(opts.fargs))
+  require("gopher").tags.rm {
-end, "*")
+    input = opts.fargs,
+    range = (opts.count ~= -1) and {
+      start = opts.line1,
+      end_ = opts.line2,
+    } or nil,
+  }
+end, "*", true)
 
 cmd("GoTagClear", function()
   require("gopher").tags.clear()
 end)
 
+-- :GoJson
+cmd("GoJson", function(opts)
+  local inp = ((opts.args ~= "" and opts.args) or nil)
+  require("gopher.json2go").json2go(inp)
+end, "*")
+
 -- :GoTest
 cmd("GoTestAdd", function()
   require("gopher").test.add()
@@ -74,7 +95,6 @@ cmd("GoMod", function(opts)
 end, "*")
 
 cmd("GoGet", function(opts)
-  vim.print(opts)
   require("gopher").get(opts.fargs)
 end, "*")
 
@@ -83,5 +103,5 @@ cmd("GoWork", function(opts)
 end, "*")
 
 cmd("GoGenerate", function(opts)
-  require("gopher").generate(opts.fargs or "")
+  require("gopher").generate(opts.fargs or { "" })
 end, "?")

scripts/docgen.lua

@@ -12,6 +12,7 @@ local files = {
   "lua/gopher/config.lua",
   "plugin/gopher.lua",
   "lua/gopher/struct_tags.lua",
+  "lua/gopher/json2go.lua",
   "lua/gopher/impl.lua",
   "lua/gopher/gotests.lua",
   "lua/gopher/iferr.lua",

scripts/minimal_init.lua

@@ -20,9 +20,9 @@ local function install_plug(plugin)
   end
 end
 
-install_plug "nvim-lua/plenary.nvim"
 install_plug "nvim-treesitter/nvim-treesitter"
 install_plug "echasnovski/mini.doc" -- used for docs generation
+install_plug "folke/tokyonight.nvim" -- theme for generating demos
 install_plug "echasnovski/mini.test"
 
 vim.env.XDG_CONFIG_HOME = root ".tests/config"
@@ -32,6 +32,8 @@ vim.env.XDG_CACHE_HOME = root ".tests/cache"
 
 vim.opt.runtimepath:append(root())
 vim.opt.packpath:append(root ".tests/site")
+vim.o.swapfile = false
+vim.o.writebackup = false
 vim.notify = vim.print
 
 -- install go treesitter parse
@@ -53,6 +55,13 @@ if #vim.api.nvim_list_uis() == 0 then
   }
 end
 
+-- set colorscheme only when running ui
+if #vim.api.nvim_list_uis() == 1 then
+  vim.cmd.colorscheme "tokyonight-night"
+  vim.o.cursorline = true
+  vim.o.number = true
+end
+
 -- needed for tests, i dont know the reason why, but on start
 -- vim is not able to use treesitter for go by default
 vim.api.nvim_create_autocmd("FileType", {

spec/fixtures/comment/interface_many_method_input.go

@@ -0,0 +1,6 @@
+package main
+
+type Testinger interface {
+	Get(id string) int
+	Set(id string, val int)
+}

spec/fixtures/comment/interface_many_method_output.go

@@ -0,0 +1,7 @@
+package main
+
+type Testinger interface {
+	Get(id string) int
+	// Set 
+	Set(id string, val int)
+}

spec/fixtures/comment/interface_method_input.go

@@ -0,0 +1,5 @@
+package main
+
+type Testinger interface {
+	Method(input string) error
+}

spec/fixtures/comment/interface_method_output.go

@@ -0,0 +1,6 @@
+package main
+
+type Testinger interface {
+	// Method 
+	Method(input string) error
+}

spec/fixtures/comment/many_structs_fields_input.go

@@ -0,0 +1,18 @@
+package main
+
+type (
+	TestOne struct {
+		Asdf string
+		ID   int
+	}
+
+	TestTwo struct {
+		Fesa int
+		A    bool
+	}
+
+	TestThree struct {
+		Asufj int
+		Fs    string
+	}
+)

spec/fixtures/comment/many_structs_fields_output.go

@@ -0,0 +1,19 @@
+package main
+
+type (
+	TestOne struct {
+		Asdf string
+		ID   int
+	}
+
+	TestTwo struct {
+		// Fesa 
+		Fesa int
+		A    bool
+	}
+
+	TestThree struct {
+		Asufj int
+		Fs    string
+	}
+)

spec/fixtures/comment/struct_fields_input.go

@@ -0,0 +1,7 @@
+package main
+
+type CommentStruct struct {
+	Name    string
+	Address string
+	Aliases []string
+}

spec/fixtures/comment/struct_fields_output.go

@@ -0,0 +1,8 @@
+package main
+
+type CommentStruct struct {
+	Name    string
+	// Address 
+	Address string
+	Aliases []string
+}

spec/fixtures/comment/svar_input.go

@@ -0,0 +1,5 @@
+package main
+
+func varTest() {
+	s := "something"
+}

spec/fixtures/comment/svar_output.go

@@ -0,0 +1,6 @@
+package main
+
+func varTest() {
+	// s 
+	s := "something"
+}

spec/fixtures/comment/var_input.go

@@ -0,0 +1,5 @@
+package main
+
+func test() {
+	var imAVar string
+}

spec/fixtures/comment/var_output.go

@@ -0,0 +1,6 @@
+package main
+
+func test() {
+	// imAVar 
+	var imAVar string
+}

spec/fixtures/comment/var_struct_fields_input.go

@@ -0,0 +1,8 @@
+package main
+
+func main() {
+	var s struct {
+		API string
+		Key string
+	}
+}

spec/fixtures/comment/var_struct_fields_output.go

@@ -0,0 +1,9 @@
+package main
+
+func main() {
+	var s struct {
+		API string
+		// Key 
+		Key string
+	}
+}

spec/fixtures/json2go/interativly_input.go

@@ -0,0 +1,2 @@
+package main
+

spec/fixtures/json2go/interativly_output.go

@@ -0,0 +1,5 @@
+package main
+
+type AutoGenerated struct {
+	Json bool `json:"json"`
+}

spec/fixtures/json2go/manual_input.go

@@ -0,0 +1,2 @@
+package main
+

spec/fixtures/json2go/manual_output.go

@@ -0,0 +1,7 @@
+package main
+
+type AutoGenerated struct {
+	User struct {
+		Name string `json:"name"`
+	} `json:"user"`
+}

spec/fixtures/tags/add_range_input.go

@@ -0,0 +1,14 @@
+package main
+
+type Test struct {
+	ID      int
+	Name    string
+	Num     int64
+	Cost    int
+	Thingy  []string
+	Testing int
+	Another struct {
+		First  int
+		Second string
+	}
+}

spec/fixtures/tags/add_range_output.go

@@ -0,0 +1,14 @@
+package main
+
+type Test struct {
+	ID      int
+	Name    string `gopher:"name"`
+	Num     int64  `gopher:"num"`
+	Cost    int    `gopher:"cost"`
+	Thingy  []string
+	Testing int
+	Another struct {
+		First  int
+		Second string
+	}
+}

spec/fixtures/tags/overwrite_default_option_input.go

@@ -0,0 +1,8 @@
+package main
+
+type Test struct {
+	ID      int
+	Another struct {
+		Second string
+	}
+}

spec/fixtures/tags/overwrite_default_option_output.go

@@ -0,0 +1,8 @@
+package main
+
+type Test struct {
+	ID      int `xml:"id,otheroption"`
+	Another struct {
+		Second string `xml:"second,otheroption"`
+	} `xml:"another,otheroption"`
+}

spec/fixtures/tags/remove_range_input.go

@@ -0,0 +1,14 @@
+package main
+
+type Test struct {
+	ID      int      `asdf:"id"`
+	Name    string   `asdf:"name"`
+	Num     int64    `asdf:"num"`
+	Cost    int      `asdf:"cost"`
+	Thingy  []string `asdf:"thingy"`
+	Testing int      `asdf:"testing"`
+	Another struct {
+		First  int    `asdf:"first"`
+		Second string `asdf:"second"`
+	} `asdf:"another"`
+}

spec/fixtures/tags/remove_range_output.go

@@ -0,0 +1,14 @@
+package main
+
+type Test struct {
+	ID      int      `asdf:"id"`
+	Name    string   `asdf:"name"`
+	Num     int64
+	Cost    int
+	Thingy  []string
+	Testing int      `asdf:"testing"`
+	Another struct {
+		First  int    `asdf:"first"`
+		Second string `asdf:"second"`
+	} `asdf:"another"`
+}

spec/fixtures/tags/remove_with_option_input.go

@@ -0,0 +1,11 @@
+package main
+
+type Test struct {
+	ID      int    `json:"id,omitempty" xml:"id,someoption"`
+	Name    string `json:"name,omitempty" xml:"name,someoption"`
+	Num     int64  `json:"num,omitempty" xml:"num,someoption"`
+	Another struct {
+		First  int    `json:"first,omitempty" xml:"first,someoption"`
+		Second string `json:"second,omitempty" xml:"second,someoption"`
+	} `json:"another,omitempty" xml:"another,someoption"`
+}

spec/fixtures/tags/remove_with_option_output.go

@@ -0,0 +1,11 @@
+package main
+
+type Test struct {
+	ID      int    `xml:"id,someoption"`
+	Name    string `xml:"name,someoption"`
+	Num     int64  `xml:"num,someoption"`
+	Another struct {
+		First  int    `xml:"first,someoption"`
+		Second string `xml:"second,someoption"`
+	} `xml:"another,someoption"`
+}

spec/fixtures/tags/with_default_option_input.go

@@ -0,0 +1,8 @@
+package main
+
+type Test struct {
+	ID      int
+	Another struct {
+		Second string
+	}
+}

spec/fixtures/tags/with_default_option_output.go

@@ -0,0 +1,8 @@
+package main
+
+type Test struct {
+	ID      int `xml:"id,theoption"`
+	Another struct {
+		Second string `xml:"second,theoption"`
+	} `xml:"another,theoption"`
+}

spec/fixtures/tags/with_option_input.go

@@ -0,0 +1,11 @@
+package main
+
+type Test struct {
+	ID      int
+	Name    string
+	Num     int64
+	Another struct {
+		First  int
+		Second string
+	}
+}

spec/fixtures/tags/with_option_output.go

@@ -0,0 +1,11 @@
+package main
+
+type Test struct {
+	ID      int    `json:"id,omitempty"`
+	Name    string `json:"name,omitempty"`
+	Num     int64  `json:"num,omitempty"`
+	Another struct {
+		First  int    `json:"first,omitempty"`
+		Second string `json:"second,omitempty"`
+	} `json:"another,omitempty"`
+}

spec/integration/comment_test.lua

@@ -1,5 +1,5 @@
 local t = require "spec.testutils"
-local child, T = t.setup "comment"
+local child, T, comment = t.setup "comment"
 
 local function do_the_test(fixture, pos)
   local rs = t.setup_test("comment/" .. fixture, child, pos)
@@ -10,27 +10,55 @@ local function do_the_test(fixture, pos)
   t.cleanup(rs)
 end
 
-T["comment"]["should add comment to package"] = function()
+comment["should add comment to package"] = function()
   do_the_test("package", { 1, 1 })
 end
 
-T["comment"]["should add comment to struct"] = function()
+comment["should add comment to struct"] = function()
   do_the_test("struct", { 4, 1 })
 end
 
-T["comment"]["should add comment to function"] = function()
+comment["should add a comment on struct field"] = function()
+  do_the_test("struct_fields", { 5, 8 })
+end
+
+comment["should add a comment on var struct field"] = function()
+  do_the_test("var_struct_fields", { 6, 4 })
+end
+
+comment["should add a comment on one field of many structs"] = function()
+  do_the_test("many_structs_fields", { 10, 4 })
+end
+
+comment["should add comment to function"] = function()
   do_the_test("func", { 3, 1 })
 end
 
-T["comment"]["should add comment to method"] = function()
+comment["should add comment to method"] = function()
   do_the_test("method", { 5, 1 })
 end
 
-T["comment"]["should add comment to interface"] = function()
+comment["should add comment to interface"] = function()
   do_the_test("interface", { 3, 6 })
 end
 
-T["comment"]["otherwise should add // above cursor"] = function()
+comment["should add comment on interface method"] = function()
+  do_the_test("interface_method", { 4, 2 })
+end
+
+comment["should add a comment on interface with many method"] = function()
+  do_the_test("interface_many_method", { 5, 2 })
+end
+
+comment["should add a comment on a var"] = function()
+  do_the_test("var", { 4, 2 })
+end
+
+comment["should add a comment on a short declared var"] = function()
+  do_the_test("svar", { 4, 8 })
+end
+
+comment["otherwise should add // above cursor"] = function()
   do_the_test("empty", { 1, 1 })
 end
 

spec/integration/gotests_test.lua

@@ -1,5 +1,5 @@
 local t = require "spec.testutils"
-local child, T = t.setup "gotests"
+local child, T, gotests = t.setup "gotests"
 
 --- NOTE: :GoTestAdd is the only place that has actual logic
 --- All other parts are handled `gotests` itself.
@@ -10,7 +10,7 @@ local function read_testfile(fpath)
   return t.readfile(fpath:gsub(".go", "_test.go"))
 end
 
-T["gotests"]["should add test for function under cursor"] = function()
+gotests["should add test for function under cursor"] = function()
   local rs = t.setup_test("tests/function", child, { 3, 5 })
   child.cmd "GoTestAdd"
 
@@ -18,7 +18,7 @@ T["gotests"]["should add test for function under cursor"] = function()
   t.cleanup(rs)
 end
 
-T["gotests"]["should add test for method under cursor"] = function()
+gotests["should add test for method under cursor"] = function()
   local rs = t.setup_test("tests/method", child, { 5, 19 })
   child.cmd "GoTestAdd"
 

spec/integration/iferr_test.lua

@@ -1,7 +1,7 @@
 local t = require "spec.testutils"
-local child, T = t.setup "iferr"
+local child, T, iferr = t.setup "iferr"
 
-T["iferr"]["should add if != nil {"] = function()
+iferr["should add if != nil {"] = function()
   local rs = t.setup_test("iferr/iferr", child, { 8, 2 })
   child.cmd "GoIfErr"
   child.cmd "write"
@@ -10,11 +10,12 @@ T["iferr"]["should add if != nil {"] = function()
   t.cleanup(rs)
 end
 
-T["iferr"]["should add if err with custom message"] = function()
+iferr["should add if err with custom message"] = function()
   child.lua [[
     require("gopher").setup {
       iferr = { message = 'fmt.Errorf("failed to %w", err)' }
-  } ]]
+    }
+  ]]
 
   local rs = t.setup_test("iferr/message", child, { 6, 2 })
   child.cmd "GoIfErr"

spec/integration/impl_test.lua

@@ -1,7 +1,7 @@
 local t = require "spec.testutils"
-local child, T = t.setup "impl"
+local child, T, impl = t.setup "impl"
 
-T["impl"]["should do impl with 'w io.Writer'"] = function()
+impl["should do impl with 'w io.Writer'"] = function()
   local rs = t.setup_test("impl/writer", child, { 3, 0 })
   child.cmd "GoImpl w io.Writer"
   child.cmd "write"
@@ -12,7 +12,7 @@ T["impl"]["should do impl with 'w io.Writer'"] = function()
   t.cleanup(rs)
 end
 
-T["impl"]["should work with full input, 'r Read io.Reader'"] = function()
+impl["should work with full input, 'r Read io.Reader'"] = function()
   local rs = t.setup_test("impl/reader", child)
   child.cmd "GoImpl r Read io.Reader"
   child.cmd "write"
@@ -22,7 +22,7 @@ T["impl"]["should work with full input, 'r Read io.Reader'"] = function()
   t.cleanup(rs)
 end
 
-T["impl"]["should work with minimal input 'io.Closer'"] = function()
+impl["should work with minimal input 'io.Closer'"] = function()
   local rs = t.setup_test("impl/closer", child, { 3, 6 })
   child.cmd "GoImpl io.Closer"
   child.cmd "write"

spec/integration/json2go_test.lua

@@ -0,0 +1,25 @@
+local t = require "spec.testutils"
+local child, T, json2go = t.setup "json2go"
+
+json2go["should convert interativly"] = function()
+  local rs = t.setup_test("json2go/interativly", child, { 2, 0 })
+  child.cmd "GoJson"
+  child.type_keys [[{"json": true}]]
+  child.type_keys "<Esc>"
+  child.cmd "wq" -- quit prompt
+  child.cmd "write" -- the fixture file
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+json2go["should convert argument"] = function()
+  local rs = t.setup_test("json2go/manual", child, { 2, 0 })
+  child.cmd [[GoJson {"user": {"name": "user-ovic"}}]]
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+return T

spec/integration/struct_tags_test.lua

@@ -1,7 +1,7 @@
 local t = require "spec.testutils"
-local child, T = t.setup "struct_tags"
+local child, T, struct_tags = t.setup "struct_tags"
 
-T["struct_tags"]["should add tag"] = function()
+struct_tags["should add tag"] = function()
   local rs = t.setup_test("tags/add", child, { 3, 6 })
   child.cmd "GoTagAdd json"
   child.cmd "write"
@@ -10,7 +10,7 @@ T["struct_tags"]["should add tag"] = function()
   t.cleanup(rs)
 end
 
-T["struct_tags"]["should remove tag"] = function()
+struct_tags["should remove tag"] = function()
   local rs = t.setup_test("tags/remove", child, { 4, 6 })
   child.cmd "GoTagRm json"
   child.cmd "write"
@@ -19,7 +19,7 @@ T["struct_tags"]["should remove tag"] = function()
   t.cleanup(rs)
 end
 
-T["struct_tags"]["should be able to handle many structs"] = function()
+struct_tags["should be able to handle many structs"] = function()
   local rs = t.setup_test("tags/many", child, { 10, 3 })
   child.cmd "GoTagAdd testing"
   child.cmd "write"
@@ -28,7 +28,7 @@ T["struct_tags"]["should be able to handle many structs"] = function()
   t.cleanup(rs)
 end
 
-T["struct_tags"]["should clear struct"] = function()
+struct_tags["should clear struct"] = function()
   local rs = t.setup_test("tags/clear", child, { 3, 1 })
   child.cmd "GoTagClear"
   child.cmd "write"
@@ -37,7 +37,7 @@ T["struct_tags"]["should clear struct"] = function()
   t.cleanup(rs)
 end
 
-T["struct_tags"]["should add more than one tag"] = function()
+struct_tags["should add more than one tag"] = function()
   local tmp = t.tmpfile()
   local fixtures = t.get_fixtures "tags/add_many"
   t.writefile(tmp, fixtures.input)
@@ -60,7 +60,7 @@ T["struct_tags"]["should add more than one tag"] = function()
   t.cleanup { tmp = tmp }
 end
 
-T["struct_tags"]["should add tags on var"] = function()
+struct_tags["should add tags on var"] = function()
   local rs = t.setup_test("tags/var", child, { 5, 6 })
   child.cmd "GoTagAdd yaml"
   child.cmd "write"
@@ -69,7 +69,7 @@ T["struct_tags"]["should add tags on var"] = function()
   t.cleanup(rs)
 end
 
-T["struct_tags"]["should add tags on short declr var"] = function()
+struct_tags["should add tags on short declr var"] = function()
   local rs = t.setup_test("tags/svar", child, { 4, 3 })
   child.cmd "GoTagAdd xml"
   child.cmd "write"
@@ -78,4 +78,70 @@ T["struct_tags"]["should add tags on short declr var"] = function()
   t.cleanup(rs)
 end
 
+struct_tags["should add tag with range"] = function()
+  local rs = t.setup_test("tags/add_range", child, { 5, 1 })
+  child.cmd ".,+2GoTagAdd gopher"
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+struct_tags["should remove tag with range"] = function()
+  local rs = t.setup_test("tags/remove_range", child, { 6, 1 })
+  child.cmd ".,+2GoTagRm asdf"
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+struct_tags["should add tags with option"] = function()
+  local rs = t.setup_test("tags/with_option", child, { 3, 6 })
+  child.cmd "GoTagAdd json=omitempty"
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+struct_tags["should add tags with default option"] = function()
+  child.lua [[
+    require("gopher").setup {
+      gotag = { option = "xml=theoption" },
+    }
+  ]]
+
+  local rs = t.setup_test("tags/with_default_option", child, { 3, 6 })
+  child.cmd "GoTagAdd xml"
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+struct_tags["should add tags and overwrite default option"] = function()
+  child.lua [[
+    require("gopher").setup {
+      gotag = { option = "xml=theoption" },
+    }
+  ]]
+
+  local rs = t.setup_test("tags/overwrite_default_option", child, { 3, 6 })
+  child.cmd "GoTagAdd xml=otheroption"
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
+struct_tags["should remove tag with specified option"] = function()
+  local rs = t.setup_test("tags/remove_with_option", child, { 3, 6 })
+  child.cmd "GoTagRm json=omitempty"
+  child.cmd "write"
+
+  t.eq(t.readfile(rs.tmp), rs.fixtures.output)
+  t.cleanup(rs)
+end
+
 return T

spec/testutils.lua

@@ -6,9 +6,11 @@ local testutils = {}
 testutils.mininit_path = vim.fs.joinpath(base_dir, "scripts", "minimal_init.lua")
 testutils.fixtures_dir = vim.fs.joinpath(base_dir, "spec/fixtures")
 
----@param name string
+---@param mod string Module name for which to create a nested test set.
----@return MiniTest.child, table
+---@return MiniTest.child child nvim client.
-function testutils.setup(name)
+---@return table T root test set created by `MiniTest.new_set()`.
+---@return table mod_name nested set of tests in `T[mod]`.
+function testutils.setup(mod)
   local child = MiniTest.new_child_neovim()
   local T = MiniTest.new_set {
     hooks = {
@@ -19,8 +21,8 @@ function testutils.setup(name)
     },
   }
 
-  T[name] = MiniTest.new_set {}
+  T[mod] = MiniTest.new_set {}
-  return child, T
+  return child, T, T[mod]
 end
 
 ---@generic T
@@ -76,6 +78,8 @@ end
 ---@param pos? number[]
 ---@return gopher.TestUtilsSetup
 function testutils.setup_test(fixture, child, pos)
+  vim.validate("pos", pos, "table", true)
+
   local tmp = testutils.tmpfile()
   local fixtures = testutils.get_fixtures(fixture)
 
@@ -84,6 +88,8 @@ function testutils.setup_test(fixture, child, pos)
 
   local bufnr = child.fn.bufnr(tmp)
   if pos then
+    assert(#pos == 2, "invalid cursor position")
+
     child.fn.setpos(".", { bufnr, unpack(pos) })
   end
 

spec/unit/config_test.lua

@@ -0,0 +1,25 @@
+local t = require "spec.testutils"
+local _, T, config = t.setup "config"
+
+config["can be called without any arguments passed"] = function()
+  ---@diagnostic disable-next-line: missing-parameter
+  require("gopher").setup()
+end
+
+config["can be called with empty table"] = function()
+  ---@diagnostic disable-next-line: missing-fields
+  require("gopher").setup {}
+end
+
+config["should change option"] = function()
+  local log_level = 1234567890
+
+  ---@diagnostic disable-next-line: missing-fields
+  require("gopher").setup {
+    log_level = log_level,
+  }
+
+  t.eq(log_level, require("gopher.config").log_level)
+end
+
+return T

spec/unit/struct_tag_test.lua

@@ -0,0 +1,68 @@
+local t = require "spec.testutils"
+local _, T, st = t.setup "struct_tags"
+
+st["should parse tags"] = function()
+  local out = require("gopher.struct_tags").parse_args { "json", "yaml", "etc" }
+
+  t.eq(out.tags, "json,yaml,etc")
+  t.eq(out.options, "")
+end
+
+st["should parse tags separated by commas"] = function()
+  local out = require("gopher.struct_tags").parse_args { "json,yaml,etc" }
+
+  t.eq(out.tags, "json,yaml,etc")
+  t.eq(out.options, "")
+end
+
+st["should parse tags separated by command and spaces"] = function()
+  local out = require("gopher.struct_tags").parse_args {
+    "json,yaml",
+    "json=omitempty",
+    "xml=something",
+  }
+
+  t.eq(out.tags, "json,yaml,xml")
+  t.eq(out.options, "json=omitempty,xml=something")
+end
+
+st["should parse tag with an option"] = function()
+  local out = require("gopher.struct_tags").parse_args {
+    "json=omitempty",
+    "xml",
+    "xml=theoption",
+  }
+
+  t.eq(out.tags, "json,xml")
+  t.eq(out.options, "json=omitempty,xml=theoption")
+end
+
+st["should parse tags with an option"] = function()
+  local out = require("gopher.struct_tags").parse_args { "json=omitempty", "yaml" }
+
+  t.eq(out.tags, "json,yaml")
+  t.eq(out.options, "json=omitempty")
+end
+
+st["should parse tags with an option separated with comma"] = function()
+  local out = require("gopher.struct_tags").parse_args { "json=omitempty,yaml" }
+
+  t.eq(out.tags, "json,yaml")
+  t.eq(out.options, "json=omitempty")
+end
+
+st["should parse tags with options specified separately"] = function()
+  local out = require("gopher.struct_tags").parse_args { "json", "yaml", "json=omitempty" }
+
+  t.eq(out.tags, "json,yaml")
+  t.eq(out.options, "json=omitempty")
+end
+
+st["should parse tags with options specified separately and separated by comma"] = function()
+  local out = require("gopher.struct_tags").parse_args { "json,yaml,json=omitempty" }
+
+  t.eq(out.tags, "json,yaml")
+  t.eq(out.options, "json=omitempty")
+end
+
+return T

spec/unit/utils_test.lua

@@ -1,14 +1,14 @@
 local t = require "spec.testutils"
-local _, T = t.setup "utils"
+local _, T, utils = t.setup "utils"
 
-T["utils"]["should .remove_empty_lines()"] = function()
+utils["should .remove_empty_lines()"] = function()
   local u = require "gopher._utils"
   local inp = { "hi", "", "a", "", "", "asdf" }
 
   t.eq(u.remove_empty_lines(inp), { "hi", "a", "asdf" })
 end
 
-T["utils"]["should .readfile_joined()"] = function()
+utils["should .readfile_joined()"] = function()
   local data = "line1\nline2\nline3"
   local tmp = t.tmpfile()
   local u = require "gopher._utils"
@@ -17,9 +17,43 @@ T["utils"]["should .readfile_joined()"] = function()
   t.eq(u.readfile_joined(tmp), data)
 end
 
-T["utils"]["should .trimend()"] = function()
+utils["should .trimend()"] = function()
   local u = require "gopher._utils"
   t.eq(u.trimend "  hi   ", "  hi")
 end
 
+utils["should add .indent() spaces"] = function()
+  local u = require "gopher._utils"
+  local line = "    func Test() error {"
+  local indent = 4
+
+  t.eq("    ", u.indent(line, indent))
+end
+
+utils["should add .indent() a tab"] = function()
+  local u = require "gopher._utils"
+  local line = "\tfunc Test() error {"
+  local indent = 1
+
+  t.eq("\t", u.indent(line, indent))
+end
+
+utils["should add .indent() 2 tabs"] = function()
+  local u = require "gopher._utils"
+  local line = "\t\tfunc Test() error {"
+  local indent = 2
+
+  t.eq("\t\t", u.indent(line, indent))
+end
+
+utils["should .list_unique on list with duplicates"] = function()
+  local u = require "gopher._utils"
+  t.eq({ "json", "xml" }, u.list_unique { "json", "xml", "json" })
+end
+
+utils["should .list_unique on list with no duplicates"] = function()
+  local u = require "gopher._utils"
+  t.eq({ "json", "xml" }, u.list_unique { "json", "xml" })
+end
+
 return T

vhs/Taskfile.yml

@@ -0,0 +1,23 @@
+version: "3"
+tasks:
+  generate:
+    deps:
+      - comment
+      - iferr
+      - tags
+      - impl
+
+  comment:
+    cmd: vhs comment.tape
+
+  iferr:
+    cmd: vhs iferr.tape
+
+  tags:
+    cmd: vhs tags.tape
+
+  impl:
+    cmd: vhs impl.tape
+
+  json2go:
+    cmd: vhs json2go.tape

vhs/comment.go

@@ -0,0 +1,7 @@
+package demos
+
+func doSomethingImportant() {}
+
+type User struct{}
+
+type DataProvider interface{}

vhs/comment.tape

@@ -0,0 +1,29 @@
+Output comment.gif
+Require nvim
+
+Set FontFamily "JetBrains Mono"
+Set Height 800
+Set Width 1500
+Set Padding 20
+Set Shell "bash"
+Set Theme "tokyonight"
+Set TypingSpeed 250ms
+
+Hide Type@0ms "./nvim.sh comment.go" Enter Show
+
+# package
+Type ":GoCmt" Enter Sleep 500ms Escape Sleep 700ms
+
+# func
+Type@400ms "jjj"
+Type ":GoCmt" Enter Sleep 500ms Escape Sleep 700ms
+
+# struct
+Type@400ms "jjj"
+Type ":GoCmt" Enter Sleep 500ms Escape Sleep 700ms
+
+# interface
+Type@400ms "jjj"
+Type ":GoCmt" Enter Sleep 500ms Escape Sleep 700ms
+
+Sleep 5s

vhs/go.mod

@@ -0,0 +1,3 @@
+module demos
+
+go 1.25.0

vhs/iferr.go

@@ -0,0 +1,11 @@
+package demos
+
+func ifErr() error {
+	out, err := doSomething()
+
+	_ = out
+}
+
+func doSomething() (string, error) {
+	return "", nil
+}

vhs/iferr.tape

@@ -0,0 +1,18 @@
+Output iferr.gif
+Require nvim
+Require iferr
+
+Set FontFamily "JetBrains Mono"
+Set Height 800
+Set Width 1500
+Set Padding 20
+Set Shell "bash"
+Set Theme "tokyonight"
+Set TypingSpeed 250ms
+
+Hide Type@0ms "./nvim.sh iferr.go" Enter Show
+
+Type "3j"
+Type ":GoIfErr" Sleep 500ms Enter
+
+Sleep 5s

vhs/impl.go

@@ -0,0 +1,3 @@
+package demos
+
+type CloserExample struct{}

vhs/impl.tape

@@ -0,0 +1,18 @@
+Output impl.gif
+Require nvim
+Require impl
+
+Set FontFamily "JetBrains Mono"
+Set Height 800
+Set Width 1500
+Set Padding 20
+Set Shell "bash"
+Set Theme "tokyonight"
+Set TypingSpeed 250ms
+
+Hide Type@0ms "./nvim.sh impl.go" Enter Show
+
+Type "2j"
+Type ":GoImpl c io.Reader" Sleep 700ms Enter
+
+Sleep 5s

vhs/json2go.go

@@ -0,0 +1,2 @@
+package main
+

vhs/json2go.tape

@@ -0,0 +1,27 @@
+Output json2go.gif
+Require nvim
+Require json2go
+
+Set FontFamily "JetBrains Mono"
+Set Height 800
+Set Width 1500
+Set Padding 20
+Set Shell "bash"
+Set Theme "tokyonight"
+Set TypingSpeed 250ms
+
+Hide Type@0ms "./nvim.sh json2go.go" Enter Show
+
+Type@0ms "G"
+Type@400ms ":GoJson" Sleep 500ms Enter
+Type@70ms "{" Enter
+Type@70ms `"json": true,` Enter
+Type@70ms `"user": {"name": "Name", "of_age": true}` Enter
+Type@70ms "}"
+Escape Type@500ms ":wq" Enter
+Sleep 1s
+
+Type@25ms "G2o" Escape
+Type@120ms `:GoJson {"json": true}` Enter
+
+Sleep 5s

vhs/nvim.sh

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+nvim --clean -u "../scripts/minimal_init.lua" $@

vhs/tags.go

@@ -0,0 +1,12 @@
+package demos
+
+type AddTagsToMe struct {
+	Name    string
+	ID      int
+	Address string
+	Aliases []string
+	Nested  struct {
+		Foo string
+		Bar float32
+	}
+}

vhs/tags.tape

@@ -0,0 +1,31 @@
+Output tags.gif
+Require nvim
+Require gomodifytags
+
+Set FontFamily "JetBrains Mono"
+Set Height 800
+Set Width 1500
+Set Padding 20
+Set Shell "bash"
+Set Theme "tokyonight"
+Set TypingSpeed 250ms
+
+Hide Type@0ms "./nvim.sh tags.go" Enter Show
+
+Type@400ms "jjj"
+Type ":GoTagAdd json yaml" Sleep 500ms Enter
+Type@120ms ":w" Enter
+Sleep 1s
+
+Type ":GoTagRm json" Sleep 500ms Enter
+Type ":w" Enter
+Sleep 1s
+
+Type ":GoTagClear" Sleep 500ms Enter
+Type ":w" Enter
+Sleep 1s
+
+Type@400ms "jVjj"
+Type ":GoTagAdd json=omitempty" Sleep 500ms Enter
+
+Sleep 5s