fix(struct_tags): edge case with structs declared as var (#99)

* fix(struct_tags): edge case with structs declared as var

* test: test it and fix it

* fixup! test: test it and fix it

* fixup! fix(struct_tags): edge case with structs declared as var

* fixup! test: test it and fix it

spec/fixtures/tags/svar_input.go

@@ -0,0 +1,11 @@
+package main
+
+func main() {
+	s := struct {
+		API string
+		Key string
+	}{
+		API: "api.com",
+		Key: "key",
+	}
+}

spec/fixtures/tags/svar_output.go

@@ -0,0 +1,11 @@
+package main
+
+func main() {
+	s := struct {
+		API string `xml:"api"`
+		Key string `xml:"key"`
+	}{
+		API: "api.com",
+		Key: "key",
+	}
+}

spec/fixtures/tags/var_input.go

@@ -0,0 +1,8 @@
+package main
+
+func main() {
+	var a struct {
+		TestField1 string
+		TestField2 string
+	}
+}

spec/fixtures/tags/var_output.go

@@ -0,0 +1,8 @@
+package main
+
+func main() {
+	var a struct {
+		TestField1 string `yaml:"test_field_1"`
+		TestField2 string `yaml:"test_field_2"`
+	}
+}

spec/integration/struct_tags_test.lua

@@ -82,4 +82,30 @@ T["struct_tags"]["should add more than one tag"] = function()
   t.eq(t.readfile(tmp), fixtures.output)
 end
 
+T["struct_tags"]["should add tags on var"] = function()
+  local tmp = t.tmpfile()
+  local fixtures = t.get_fixtures "tags/var"
+  t.writefile(tmp, fixtures.input)
+
+  child.cmd("silent edit " .. tmp)
+  child.fn.setpos(".", { child.fn.bufnr(tmp), 5, 3 })
+  child.cmd "GoTagAdd yaml"
+  child.cmd "write"
+
+  t.eq(t.readfile(tmp), fixtures.output)
+end
+
+T["struct_tags"]["should add tags on short declr var"] = function()
+  local tmp = t.tmpfile()
+  local fixtures = t.get_fixtures "tags/svar"
+  t.writefile(tmp, fixtures.input)
+
+  child.cmd("silent edit " .. tmp)
+  child.fn.setpos(".", { child.fn.bufnr(tmp), 4, 3 })
+  child.cmd "GoTagAdd xml"
+  child.cmd "write"
+
+  t.eq(t.readfile(tmp), fixtures.output)
+end
+
 return T