json2go @ 1609c23952004c5a160a5737c4ac8e9fac80292b

M json2go.go

@@ -4,11 +4,16 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"regexp"
 	"sort"
 	"strings"
 )
 
-var ErrInvalidJSON = errors.New("invalid json")
+var identRe = regexp.MustCompile(`^[A-Za-z_][A-Za-z0-9_]*$`)
+var (
+	ErrInvalidJSON       = errors.New("invalid json")
+	ErrInvalidStructName = errors.New("invalid struct name")
+)
 
 type Transformer struct {
 	structName string
@@ -21,8 +26,11 @@
 // Transform ...
 // todo: take io.Reader as input?
 // todo: output as io.Writer?
-// todo: validate provided structName
 func (t *Transformer) Transform(structName, jsonStr string) (string, error) {
+	if !identRe.MatchString(structName) {
+		return "", ErrInvalidStructName
+	}
+
 	t.structName = structName
 
 	var input any
@@ -65,7 +73,6 @@
 	}
 }
 
-// todo: input shouldn't be map, to preserve it's order
 func (t *Transformer) buildStruct(input map[string]any) string {
 	var fields strings.Builder
 	for _, f := range mapToStructInput(input) {

M json2go_test.go

@@ -22,9 +22,10 @@ }
 
 func TestTransformer_Transform(t *testing.T) {
 	tests := map[string]struct {
-		input  string
-		output string
-		err    error
+		input      string
+		output     string
+		structName string
+		err        error
 	}{
 		"simple object": {
 			input: `{"name": "Olex", "active": true, "age": 420}`,
@@ -37,6 +38,18 @@ },
 		"invalid json": {
 			err:   ErrInvalidJSON,
 			input: `{"invalid":json}`,
+		},
+		"invalid struct name, starts with number": {
+			err:        ErrInvalidStructName,
+			structName: "1Name",
+		},
+		"invalid struct name, has space": {
+			err:        ErrInvalidStructName,
+			structName: "Name Name2",
+		},
+		"invalid struct name, has non letter/number": {
+			err:        ErrInvalidStructName,
+			structName: "Name$",
 		},
 		"snake_case to CamelCase": {
 			input: `{"first_name": "Bob", "last_name": "Bobberson"}`,
@@ -93,7 +106,12 @@
 	trans := NewTransformer()
 	for tname, tt := range tests {
 		t.Run(tname, func(t *testing.T) {
-			result, err := trans.Transform("Out", tt.input)
+			sn := "Out"
+			if tt.structName != "" {
+				sn = tt.structName
+			}
+
+			result, err := trans.Transform(sn, tt.input)
 			assertEqualErr(t, tt.err, err)
 			assertEqual(t, tt.output, result)
 		})
@@ -102,8 +120,17 @@ }
 
 func assertEqualErr(t *testing.T, expected, actual error) {
 	t.Helper()
-	if (expected != nil || actual != nil) && errors.Is(expected, actual) {
-		t.Errorf("expected: %v, got: %v\n", expected, actual)
+	if expected == nil && actual == nil {
+		return
+	}
+
+	if expected == nil || actual == nil {
+		t.Errorf("expected: %v, got: %v", expected, actual)
+		return
+	}
+
+	if !errors.Is(actual, expected) {
+		t.Errorf("expected error: %v, got: %v", expected, actual)
 	}
 }