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// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package astutil_test
import (
"bytes"
"go/ast"
"go/format"
"go/parser"
"go/token"
"testing"
"golang.org/x/tools/go/ast/astutil"
"golang.org/x/tools/internal/typeparams"
)
type rewriteTest struct {
name string
orig, want string
pre, post astutil.ApplyFunc
}
var rewriteTests = []rewriteTest{
{name: "nop", orig: "package p\n", want: "package p\n"},
{name: "replace",
orig: `package p
var x int
`,
want: `package p
var t T
`,
post: func(c *astutil.Cursor) bool {
if _, ok := c.Node().(*ast.ValueSpec); ok {
c.Replace(valspec("t", "T"))
return false
}
return true
},
},
{name: "set doc strings",
orig: `package p
const z = 0
type T struct{}
var x int
`,
want: `package p
// a foo is a foo
const z = 0
// a foo is a foo
type T struct{}
// a foo is a foo
var x int
`,
post: func(c *astutil.Cursor) bool {
if _, ok := c.Parent().(*ast.GenDecl); ok && c.Name() == "Doc" && c.Node() == nil {
c.Replace(&ast.CommentGroup{List: []*ast.Comment{{Text: "// a foo is a foo"}}})
}
return true
},
},
{name: "insert names",
orig: `package p
const a = 1
`,
want: `package p
const a, b, c = 1, 2, 3
`,
pre: func(c *astutil.Cursor) bool {
if _, ok := c.Parent().(*ast.ValueSpec); ok {
switch c.Name() {
case "Names":
c.InsertAfter(ast.NewIdent("c"))
c.InsertAfter(ast.NewIdent("b"))
case "Values":
c.InsertAfter(&ast.BasicLit{Kind: token.INT, Value: "3"})
c.InsertAfter(&ast.BasicLit{Kind: token.INT, Value: "2"})
}
}
return true
},
},
{name: "insert",
orig: `package p
var (
x int
y int
)
`,
want: `package p
var before1 int
var before2 int
var (
x int
y int
)
var after2 int
var after1 int
`,
pre: func(c *astutil.Cursor) bool {
if _, ok := c.Node().(*ast.GenDecl); ok {
c.InsertBefore(vardecl("before1", "int"))
c.InsertAfter(vardecl("after1", "int"))
c.InsertAfter(vardecl("after2", "int"))
c.InsertBefore(vardecl("before2", "int"))
}
return true
},
},
{name: "delete",
orig: `package p
var x int
var y int
var z int
`,
want: `package p
var y int
var z int
`,
pre: func(c *astutil.Cursor) bool {
n := c.Node()
if d, ok := n.(*ast.GenDecl); ok && d.Specs[0].(*ast.ValueSpec).Names[0].Name == "x" {
c.Delete()
}
return true
},
},
{name: "insertafter-delete",
orig: `package p
var x int
var y int
var z int
`,
want: `package p
var x1 int
var y int
var z int
`,
pre: func(c *astutil.Cursor) bool {
n := c.Node()
if d, ok := n.(*ast.GenDecl); ok && d.Specs[0].(*ast.ValueSpec).Names[0].Name == "x" {
c.InsertAfter(vardecl("x1", "int"))
c.Delete()
}
return true
},
},
{name: "delete-insertafter",
orig: `package p
var x int
var y int
var z int
`,
want: `package p
var y int
var x1 int
var z int
`,
pre: func(c *astutil.Cursor) bool {
n := c.Node()
if d, ok := n.(*ast.GenDecl); ok && d.Specs[0].(*ast.ValueSpec).Names[0].Name == "x" {
c.Delete()
// The cursor is now effectively atop the 'var y int' node.
c.InsertAfter(vardecl("x1", "int"))
}
return true
},
},
}
func init() {
if typeparams.Enabled {
rewriteTests = append(rewriteTests, rewriteTest{
name: "replace",
orig: `package p
type T[P1, P2 any] int
type R T[int, string]
`,
want: `package p
type S[P1, P2 any] int32
type R S[int32, string]
`,
post: func(c *astutil.Cursor) bool {
if ident, ok := c.Node().(*ast.Ident); ok {
if ident.Name == "int" {
c.Replace(ast.NewIdent("int32"))
}
if ident.Name == "T" {
c.Replace(ast.NewIdent("S"))
}
}
return true
},
})
}
}
func valspec(name, typ string) *ast.ValueSpec {
return &ast.ValueSpec{Names: []*ast.Ident{ast.NewIdent(name)},
Type: ast.NewIdent(typ),
}
}
func vardecl(name, typ string) *ast.GenDecl {
return &ast.GenDecl{
Tok: token.VAR,
Specs: []ast.Spec{valspec(name, typ)},
}
}
func TestRewrite(t *testing.T) {
t.Run("*", func(t *testing.T) {
for _, test := range rewriteTests {
test := test
t.Run(test.name, func(t *testing.T) {
t.Parallel()
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, test.name, test.orig, parser.ParseComments)
if err != nil {
t.Fatal(err)
}
n := astutil.Apply(f, test.pre, test.post)
var buf bytes.Buffer
if err := format.Node(&buf, fset, n); err != nil {
t.Fatal(err)
}
got := buf.String()
if got != test.want {
t.Errorf("got:\n\n%s\nwant:\n\n%s\n", got, test.want)
}
})
}
})
}
var sink ast.Node
func BenchmarkRewrite(b *testing.B) {
for _, test := range rewriteTests {
b.Run(test.name, func(b *testing.B) {
for i := 0; i < b.N; i++ {
b.StopTimer()
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, test.name, test.orig, parser.ParseComments)
if err != nil {
b.Fatal(err)
}
b.StartTimer()
sink = astutil.Apply(f, test.pre, test.post)
}
})
}
}
|
