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support for generic type receivers #49

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ed740c9
split TestParse with sub-tests
dgsb Dec 17, 2025
be2df58
support for generic types receiever
dgsb Dec 17, 2025
3198337
add go.mod and go.sum
dgsb Dec 17, 2025
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3 changes: 3 additions & 0 deletions go.mod
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Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
module github.com/jstemmer/gotags

go 1.25.5
Empty file added go.sum
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2 changes: 2 additions & 0 deletions parser.go
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Original file line number Diff line number Diff line change
Expand Up @@ -362,6 +362,8 @@ func getType(node ast.Node, star bool) (paramType string) {
paramType = "interface{}"
case *ast.Ellipsis:
paramType = fmt.Sprintf("...%s", getType(t.Elt, true))
case *ast.IndexExpr: // for generics type receiver
paramType = getType(t.X, star)
}
return
}
Expand Down
116 changes: 67 additions & 49 deletions parser_test.go
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Expand Up @@ -41,14 +41,15 @@ func (t TagSlice) Dump() {
type F map[TagField]string

var testCases = []struct {
label string
filename string
relative bool
basepath string
minversion int
withExtraSymbols bool
tags []Tag
}{
{filename: "testdata/const.go", tags: []Tag{
{label: "const", filename: "testdata/const.go", tags: []Tag{
tag("Test", 1, "p", F{}),
tag("Constant", 3, "c", F{"access": "public", "type": "string"}),
tag("OtherConst", 4, "c", F{"access": "public"}),
Expand All @@ -57,7 +58,7 @@ var testCases = []struct {
tag("C", 8, "c", F{"access": "public"}),
tag("D", 9, "c", F{"access": "public"}),
}},
{filename: "testdata/const.go", withExtraSymbols: true, tags: []Tag{
{label: "const with extra symbols", filename: "testdata/const.go", withExtraSymbols: true, tags: []Tag{
tag("Test", 1, "p", F{}),
tag("Constant", 3, "c", F{"access": "public", "type": "string"}),
tag("OtherConst", 4, "c", F{"access": "public"}),
Expand All @@ -72,7 +73,7 @@ var testCases = []struct {
tag("Test.C", 8, "c", F{"access": "public"}),
tag("Test.D", 9, "c", F{"access": "public"}),
}},
{filename: "testdata/func.go", tags: []Tag{
{label: "func", filename: "testdata/func.go", tags: []Tag{
tag("Test", 1, "p", F{}),
tag("Function1", 3, "f", F{"access": "public", "signature": "()", "type": "string"}),
tag("function2", 6, "f", F{"access": "private", "signature": "(p1, p2 int, p3 *string)"}),
Expand All @@ -81,8 +82,9 @@ var testCases = []struct {
tag("function5", 15, "f", F{"access": "private", "signature": "()", "type": "string, string, error"}),
tag("function6", 18, "f", F{"access": "private", "signature": "(v ...interface{})"}),
tag("function7", 21, "f", F{"access": "private", "signature": "(s ...string)"}),
tag("function8", 24, "f", F{"access": "private", "signature": "(input T)"}),
}},
{filename: "testdata/func.go", withExtraSymbols: true, tags: []Tag{
{label: "func with extra symbols", filename: "testdata/func.go", withExtraSymbols: true, tags: []Tag{
tag("Test", 1, "p", F{}),
tag("Test.Function1", 3, "f", F{"access": "public", "signature": "()", "type": "string"}),
tag("Test.function2", 6, "f", F{"access": "private", "signature": "(p1, p2 int, p3 *string)"}),
Expand All @@ -91,42 +93,44 @@ var testCases = []struct {
tag("Test.function5", 15, "f", F{"access": "private", "signature": "()", "type": "string, string, error"}),
tag("Test.function6", 18, "f", F{"access": "private", "signature": "(v ...interface{})"}),
tag("Test.function7", 21, "f", F{"access": "private", "signature": "(s ...string)"}),
tag("Test.function8", 24, "f", F{"access": "private", "signature": "(input T)"}),
tag("Function1", 3, "f", F{"access": "public", "signature": "()", "type": "string"}),
tag("function2", 6, "f", F{"access": "private", "signature": "(p1, p2 int, p3 *string)"}),
tag("function3", 9, "f", F{"access": "private", "signature": "()", "type": "bool"}),
tag("function4", 12, "f", F{"access": "private", "signature": "(p interface{})", "type": "interface{}"}),
tag("function5", 15, "f", F{"access": "private", "signature": "()", "type": "string, string, error"}),
tag("function6", 18, "f", F{"access": "private", "signature": "(v ...interface{})"}),
tag("function7", 21, "f", F{"access": "private", "signature": "(s ...string)"}),
tag("function8", 24, "f", F{"access": "private", "signature": "(input T)"}),
}},
{filename: "testdata/import.go", tags: []Tag{
{label: "import", filename: "testdata/import.go", tags: []Tag{
tag("Test", 1, "p", F{}),
tag("fmt", 3, "i", F{}),
tag("go/ast", 6, "i", F{}),
tag("go/parser", 7, "i", F{}),
}},
{filename: "testdata/import.go", withExtraSymbols: true, tags: []Tag{
{label: "import with extra symbols", filename: "testdata/import.go", withExtraSymbols: true, tags: []Tag{
tag("Test", 1, "p", F{}),
tag("fmt", 3, "i", F{}),
tag("go/ast", 6, "i", F{}),
tag("go/parser", 7, "i", F{}),
}},
{filename: "testdata/interface.go", tags: []Tag{
{label: "interface", filename: "testdata/interface.go", tags: []Tag{
tag("Test", 1, "p", F{}),
tag("InterfaceMethod", 4, "m", F{"access": "public", "signature": "(int)", "ntype": "Interface", "type": "string"}),
tag("OtherMethod", 5, "m", F{"access": "public", "signature": "()", "ntype": "Interface"}),
tag("io.Reader", 6, "e", F{"access": "public", "ntype": "Interface"}),
tag("Interface", 3, "n", F{"access": "public", "type": "interface"}),
}},
{filename: "testdata/interface.go", withExtraSymbols: true, tags: []Tag{
{label: "interface with extra symbols", filename: "testdata/interface.go", withExtraSymbols: true, tags: []Tag{
tag("Test", 1, "p", F{}),
tag("InterfaceMethod", 4, "m", F{"access": "public", "signature": "(int)", "ntype": "Interface", "type": "string"}),
tag("OtherMethod", 5, "m", F{"access": "public", "signature": "()", "ntype": "Interface"}),
tag("io.Reader", 6, "e", F{"access": "public", "ntype": "Interface"}),
tag("Interface", 3, "n", F{"access": "public", "type": "interface"}),
tag("Test.Interface", 3, "n", F{"access": "public", "type": "interface"}),
}},
{filename: "testdata/struct.go", tags: []Tag{
{label: "struct", filename: "testdata/struct.go", tags: []Tag{
tag("Test", 1, "p", F{}),
tag("Field1", 4, "w", F{"access": "public", "ctype": "Struct", "type": "int"}),
tag("Field2", 4, "w", F{"access": "public", "ctype": "Struct", "type": "int"}),
Expand All @@ -146,8 +150,11 @@ var testCases = []struct {
tag("Dial", 33, "f", F{"access": "public", "ctype": "Connection", "signature": "()", "type": "*Connection, error"}),
tag("Dial2", 39, "f", F{"access": "public", "ctype": "Connection", "signature": "()", "type": "*Connection, *Struct2"}),
tag("Dial3", 42, "f", F{"access": "public", "signature": "()", "type": "*Connection, *Connection"}),
tag("WithGenerics", 45, "t", F{"access": "public", "type": "struct"}),
tag("Field1", 46, "w", F{"access": "public", "ctype": "WithGenerics", "type": "T"}),
tag("Do", 49, "m", F{"access": "public", "ctype": "WithGenerics", "signature": "(input T)"}),
}},
{filename: "testdata/struct.go", withExtraSymbols: true, tags: []Tag{
{label: "struct with extra symbols", filename: "testdata/struct.go", withExtraSymbols: true, tags: []Tag{
tag("Test", 1, "p", F{}),
tag("Field1", 4, "w", F{"access": "public", "ctype": "Struct", "type": "int"}),
tag("Field2", 4, "w", F{"access": "public", "ctype": "Struct", "type": "int"}),
Expand Down Expand Up @@ -183,8 +190,15 @@ var testCases = []struct {
tag("Test.Dial2", 39, "f", F{"access": "public", "ctype": "Connection", "signature": "()", "type": "*Connection, *Struct2"}),
tag("Dial3", 42, "f", F{"access": "public", "signature": "()", "type": "*Connection, *Connection"}),
tag("Test.Dial3", 42, "f", F{"access": "public", "signature": "()", "type": "*Connection, *Connection"}),
tag("WithGenerics", 45, "t", F{"access": "public", "type": "struct"}),
tag("Test.WithGenerics", 45, "t", F{"access": "public", "type": "struct"}),
tag("Field1", 46, "w", F{"access": "public", "ctype": "WithGenerics", "type": "T"}),
tag("Do", 49, "m", F{"access": "public", "ctype": "WithGenerics", "signature": "(input T)"}),
tag("WithGenerics.Do", 49, "m", F{"access": "public", "ctype": "WithGenerics", "signature": "(input T)"}),
tag("Test.WithGenerics.Do", 49, "m", F{"access": "public", "ctype": "WithGenerics", "signature": "(input T)"}),
tag("Test.Do", 49, "m", F{"access": "public", "ctype": "WithGenerics", "signature": "(input T)"}),
}},
{filename: "testdata/type.go", tags: []Tag{
{label: "type", filename: "testdata/type.go", tags: []Tag{
tag("Test", 1, "p", F{}),
tag("testType", 3, "t", F{"access": "private", "type": "int"}),
tag("testArrayType", 4, "t", F{"access": "private", "type": "[4]int"}),
Expand All @@ -195,7 +209,7 @@ var testCases = []struct {
tag("testMapType", 9, "t", F{"access": "private", "type": "map[string]bool"}),
tag("testChanType", 10, "t", F{"access": "private", "type": "chan bool"}),
}},
{filename: "testdata/type.go", withExtraSymbols: true, tags: []Tag{
{label: "type with extra symbols", filename: "testdata/type.go", withExtraSymbols: true, tags: []Tag{
tag("Test", 1, "p", F{}),
tag("testType", 3, "t", F{"access": "private", "type": "int"}),
tag("testArrayType", 4, "t", F{"access": "private", "type": "[4]int"}),
Expand All @@ -214,7 +228,7 @@ var testCases = []struct {
tag("Test.testMapType", 9, "t", F{"access": "private", "type": "map[string]bool"}),
tag("Test.testChanType", 10, "t", F{"access": "private", "type": "chan bool"}),
}},
{filename: "testdata/var.go", tags: []Tag{
{label: "var", filename: "testdata/var.go", tags: []Tag{
tag("Test", 1, "p", F{}),
tag("variable1", 3, "v", F{"access": "private", "type": "int"}),
tag("variable2", 4, "v", F{"access": "private", "type": "string"}),
Expand All @@ -223,7 +237,7 @@ var testCases = []struct {
tag("C", 8, "v", F{"access": "public"}),
tag("D", 9, "v", F{"access": "public"}),
}},
{filename: "testdata/var.go", withExtraSymbols: true, tags: []Tag{
{label: "var with extra symbols", filename: "testdata/var.go", withExtraSymbols: true, tags: []Tag{
tag("Test", 1, "p", F{}),
tag("variable1", 3, "v", F{"access": "private", "type": "int"}),
tag("variable2", 4, "v", F{"access": "private", "type": "string"}),
Expand All @@ -238,18 +252,18 @@ var testCases = []struct {
tag("Test.C", 8, "v", F{"access": "public"}),
tag("Test.D", 9, "v", F{"access": "public"}),
}},
{filename: "testdata/simple.go", relative: true, basepath: "dir", tags: []Tag{
{label: "simple", filename: "testdata/simple.go", relative: true, basepath: "dir", tags: []Tag{
{Name: "main", File: "../testdata/simple.go", Address: "1", Type: "p", Fields: F{"line": "1"}},
}},
{filename: "testdata/simple.go", withExtraSymbols: true, relative: true, basepath: "dir", tags: []Tag{
{label: "simple with extra symbols", filename: "testdata/simple.go", withExtraSymbols: true, relative: true, basepath: "dir", tags: []Tag{
{Name: "main", File: "../testdata/simple.go", Address: "1", Type: "p", Fields: F{"line": "1"}},
}},
{filename: "testdata/range.go", minversion: 4, tags: []Tag{
{label: "range", filename: "testdata/range.go", minversion: 4, tags: []Tag{
tag("main", 1, "p", F{}),
tag("fmt", 3, "i", F{}),
tag("main", 5, "f", F{"access": "private", "signature": "()"}),
}},
{filename: "testdata/range.go", withExtraSymbols: true, minversion: 4, tags: []Tag{
{label: "range with extra symbols", filename: "testdata/range.go", withExtraSymbols: true, minversion: 4, tags: []Tag{
tag("main", 1, "p", F{}),
tag("fmt", 3, "i", F{}),
tag("main", 5, "f", F{"access": "private", "signature": "()"}),
Expand All @@ -259,44 +273,48 @@ var testCases = []struct {

func TestParse(t *testing.T) {
for _, testCase := range testCases {
if testCase.minversion > 0 && extractVersionCode(runtime.Version()) < testCase.minversion {
t.Skipf("[%s] skipping test. Version is %s, but test requires at least go1.%d", testCase.filename, runtime.Version(), testCase.minversion)
continue
}

basepath, err := filepath.Abs(testCase.basepath)
if err != nil {
t.Errorf("[%s] could not determine base path: %s\n", testCase.filename, err)
continue
}
t.Run(testCase.label, func(t *testing.T) {
if testCase.minversion > 0 && extractVersionCode(runtime.Version()) < testCase.minversion {
t.Skipf("[%s] skipping test. Version is %s, but test requires at least go1.%d", testCase.filename, runtime.Version(), testCase.minversion)
}

var extra FieldSet
if testCase.withExtraSymbols {
extra = FieldSet{ExtraTags: true}
}
basepath, err := filepath.Abs(testCase.basepath)
if err != nil {
t.Fatalf("[%s] could not determine base path: %s\n", testCase.filename, err)
}

tags, err := Parse(testCase.filename, testCase.relative, basepath, extra)
if err != nil {
t.Errorf("[%s] Parse error: %s", testCase.filename, err)
continue
}
var extra FieldSet
if testCase.withExtraSymbols {
extra = FieldSet{ExtraTags: true}
}

sort.Sort(TagSlice(tags))
sort.Sort(TagSlice(testCase.tags))
tags, err := Parse(testCase.filename, testCase.relative, basepath, extra)
if err != nil {
t.Fatalf("[%s] Parse error: %s", testCase.filename, err)
}

if len(tags) != len(testCase.tags) {
t.Errorf("[%s] len(tags) == %d, want %d", testCase.filename, len(tags), len(testCase.tags))
continue
}
sort.Sort(TagSlice(tags))
sort.Sort(TagSlice(testCase.tags))

for i, tag := range testCase.tags {
if len(tag.File) == 0 {
tag.File = testCase.filename
if len(tags) != len(testCase.tags) {
t.Fatalf(
"[%s] len(tags) == %d, want %d",
testCase.filename,
len(tags),
len(testCase.tags),
)
}
if tags[i].String() != tag.String() {
t.Errorf("[%s] tag(%d)\n is:%s\nwant:%s", testCase.filename, i, tags[i].String(), tag.String())

for i, tag := range testCase.tags {
if len(tag.File) == 0 {
tag.File = testCase.filename
}
if tags[i].String() != tag.String() {
t.Fatalf("[%s] tag(%d)\n is:%s\nwant:%s", testCase.filename, i, tags[i].String(), tag.String())
}

}
}
})
}
}

Expand Down
3 changes: 3 additions & 0 deletions testdata/func.go
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Expand Up @@ -20,3 +20,6 @@ func function6(v ...interface{}) {

func function7(s ...string) {
}

func function8[T any](input T) {
}
7 changes: 7 additions & 0 deletions testdata/struct.go
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Expand Up @@ -41,3 +41,10 @@ func Dial2() (*Connection, *Struct2) {

func Dial3() (a, b *Connection) {
}

type WithGenerics[T any] struct {
Field1 T
}

func (w *WithGenerics[T]) Do(input T) {
}