Allow duplicate names in package.json parsing

internal/packagejson/expected.go

@@ -68,3 +68,7 @@ func (e *Expected[T]) ExpectedJSONType() string {
 func (e *Expected[T]) ActualJSONType() string {
 	return e.actualJSONType
 }
+
+func ExpectedOf[T any](value T) Expected[T] {
+	return Expected[T]{Value: value, Valid: true, actualJSONType: (*Expected[T])(nil).ExpectedJSONType()}
+}

internal/packagejson/packagejson.go

@@ -2,6 +2,7 @@ package packagejson
 
 import (
 	json2 "github.com/go-json-experiment/json"
+	"github.com/go-json-experiment/json/jsontext"
 )
 
 type HeaderFields struct {
@@ -35,7 +36,7 @@ type Fields struct {
 
 func Parse(data []byte) (Fields, error) {
 	var f Fields
-	if err := json2.Unmarshal(data, &f); err != nil {
+	if err := json2.Unmarshal(data, &f, jsontext.AllowDuplicateNames(true)); err != nil {
 		return Fields{}, err
 	}
 	return f, nil

internal/packagejson/packagejson_test.go

@@ -6,13 +6,15 @@ import (
 	"testing"
 
 	json2 "github.com/go-json-experiment/json"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/microsoft/typescript-go/internal/ast"
 	"github.com/microsoft/typescript-go/internal/core"
 	"github.com/microsoft/typescript-go/internal/packagejson"
 	"github.com/microsoft/typescript-go/internal/parser"
 	"github.com/microsoft/typescript-go/internal/repo"
 	"github.com/microsoft/typescript-go/internal/testutil/filefixture"
 	"github.com/microsoft/typescript-go/internal/tspath"
+	"gotest.tools/v3/assert"
 )
 
 var packageJsonFixtures = []filefixture.Fixture{
@@ -59,3 +61,44 @@ func BenchmarkPackageJSON(b *testing.B) {
 		})
 	}
 }
+
+func TestParse(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name    string
+		content string
+		want    packagejson.Fields
+	}{
+		{
+			name: "duplicate names",
+			content: `{
+				"name": "test-package",
+				"name": "test-package",
+				"version": "1.0.0"
+			}`,
+			want: packagejson.Fields{
+				HeaderFields: packagejson.HeaderFields{
+					Name:    packagejson.ExpectedOf("test-package"),
+					Version: packagejson.ExpectedOf("1.0.0"),
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := packagejson.Parse([]byte(tt.content))
+			assert.NilError(t, err)
+			assert.DeepEqual(t, got, tt.want, cmpopts.IgnoreUnexported(
+				packagejson.Fields{},
+				packagejson.HeaderFields{},
+				packagejson.Expected[string]{},
+				packagejson.Expected[map[string]string]{},
+				packagejson.ExportsOrImports{},
+			))
+		})
+	}
+}