blob: 2c617b82aeffd89d6d491b268b9de24549fa1968 [file] [log] [blame]
// Copyright 2018 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 modfile
import (
"bytes"
"fmt"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"reflect"
"strings"
"testing"
)
// exists reports whether the named file exists.
func exists(name string) bool {
_, err := os.Stat(name)
return err == nil
}
// Test that reading and then writing the golden files
// does not change their output.
func TestPrintGolden(t *testing.T) {
outs, err := filepath.Glob("testdata/*.golden")
if err != nil {
t.Fatal(err)
}
for _, out := range outs {
testPrint(t, out, out)
}
}
// testPrint is a helper for testing the printer.
// It reads the file named in, reformats it, and compares
// the result to the file named out.
func testPrint(t *testing.T, in, out string) {
data, err := ioutil.ReadFile(in)
if err != nil {
t.Error(err)
return
}
golden, err := ioutil.ReadFile(out)
if err != nil {
t.Error(err)
return
}
base := "testdata/" + filepath.Base(in)
f, err := parse(in, data)
if err != nil {
t.Error(err)
return
}
ndata := Format(f)
if !bytes.Equal(ndata, golden) {
t.Errorf("formatted %s incorrectly: diff shows -golden, +ours", base)
tdiff(t, string(golden), string(ndata))
return
}
}
// Test that when files in the testdata directory are parsed
// and printed and parsed again, we get the same parse tree
// both times.
func TestPrintParse(t *testing.T) {
outs, err := filepath.Glob("testdata/*")
if err != nil {
t.Fatal(err)
}
for _, out := range outs {
data, err := ioutil.ReadFile(out)
if err != nil {
t.Error(err)
continue
}
base := "testdata/" + filepath.Base(out)
f, err := parse(base, data)
if err != nil {
t.Errorf("parsing original: %v", err)
continue
}
ndata := Format(f)
f2, err := parse(base, ndata)
if err != nil {
t.Errorf("parsing reformatted: %v", err)
continue
}
eq := eqchecker{file: base}
if err := eq.check(f, f2); err != nil {
t.Errorf("not equal (parse/Format/parse): %v", err)
}
pf1, err := Parse(base, data, nil)
if err != nil {
switch base {
case "testdata/replace2.in", "testdata/gopkg.in.golden":
t.Errorf("should parse %v: %v", base, err)
}
}
if err == nil {
pf2, err := Parse(base, ndata, nil)
if err != nil {
t.Errorf("Parsing reformatted: %v", err)
continue
}
eq := eqchecker{file: base}
if err := eq.check(pf1, pf2); err != nil {
t.Errorf("not equal (parse/Format/Parse): %v", err)
}
ndata2, err := pf1.Format()
if err != nil {
t.Errorf("reformat: %v", err)
}
pf3, err := Parse(base, ndata2, nil)
if err != nil {
t.Errorf("Parsing reformatted2: %v", err)
continue
}
eq = eqchecker{file: base}
if err := eq.check(pf1, pf3); err != nil {
t.Errorf("not equal (Parse/Format/Parse): %v", err)
}
ndata = ndata2
}
if strings.HasSuffix(out, ".in") {
golden, err := ioutil.ReadFile(strings.TrimSuffix(out, ".in") + ".golden")
if err != nil {
t.Error(err)
continue
}
if !bytes.Equal(ndata, golden) {
t.Errorf("formatted %s incorrectly: diff shows -golden, +ours", base)
tdiff(t, string(golden), string(ndata))
return
}
}
}
}
// An eqchecker holds state for checking the equality of two parse trees.
type eqchecker struct {
file string
pos Position
}
// errorf returns an error described by the printf-style format and arguments,
// inserting the current file position before the error text.
func (eq *eqchecker) errorf(format string, args ...interface{}) error {
return fmt.Errorf("%s:%d: %s", eq.file, eq.pos.Line,
fmt.Sprintf(format, args...))
}
// check checks that v and w represent the same parse tree.
// If not, it returns an error describing the first difference.
func (eq *eqchecker) check(v, w interface{}) error {
return eq.checkValue(reflect.ValueOf(v), reflect.ValueOf(w))
}
var (
posType = reflect.TypeOf(Position{})
commentsType = reflect.TypeOf(Comments{})
)
// checkValue checks that v and w represent the same parse tree.
// If not, it returns an error describing the first difference.
func (eq *eqchecker) checkValue(v, w reflect.Value) error {
// inner returns the innermost expression for v.
// if v is a non-nil interface value, it returns the concrete
// value in the interface.
inner := func(v reflect.Value) reflect.Value {
for {
if v.Kind() == reflect.Interface && !v.IsNil() {
v = v.Elem()
continue
}
break
}
return v
}
v = inner(v)
w = inner(w)
if v.Kind() == reflect.Invalid && w.Kind() == reflect.Invalid {
return nil
}
if v.Kind() == reflect.Invalid {
return eq.errorf("nil interface became %s", w.Type())
}
if w.Kind() == reflect.Invalid {
return eq.errorf("%s became nil interface", v.Type())
}
if v.Type() != w.Type() {
return eq.errorf("%s became %s", v.Type(), w.Type())
}
if p, ok := v.Interface().(Expr); ok {
eq.pos, _ = p.Span()
}
switch v.Kind() {
default:
return eq.errorf("unexpected type %s", v.Type())
case reflect.Bool, reflect.Int, reflect.String:
vi := v.Interface()
wi := w.Interface()
if vi != wi {
return eq.errorf("%v became %v", vi, wi)
}
case reflect.Slice:
vl := v.Len()
wl := w.Len()
for i := 0; i < vl || i < wl; i++ {
if i >= vl {
return eq.errorf("unexpected %s", w.Index(i).Type())
}
if i >= wl {
return eq.errorf("missing %s", v.Index(i).Type())
}
if err := eq.checkValue(v.Index(i), w.Index(i)); err != nil {
return err
}
}
case reflect.Struct:
// Fields in struct must match.
t := v.Type()
n := t.NumField()
for i := 0; i < n; i++ {
tf := t.Field(i)
switch {
default:
if err := eq.checkValue(v.Field(i), w.Field(i)); err != nil {
return err
}
case tf.Type == posType: // ignore positions
case tf.Type == commentsType: // ignore comment assignment
}
}
case reflect.Ptr, reflect.Interface:
if v.IsNil() != w.IsNil() {
if v.IsNil() {
return eq.errorf("unexpected %s", w.Elem().Type())
}
return eq.errorf("missing %s", v.Elem().Type())
}
if err := eq.checkValue(v.Elem(), w.Elem()); err != nil {
return err
}
}
return nil
}
// diff returns the output of running diff on b1 and b2.
func diff(b1, b2 []byte) (data []byte, err error) {
f1, err := ioutil.TempFile("", "testdiff")
if err != nil {
return nil, err
}
defer os.Remove(f1.Name())
defer f1.Close()
f2, err := ioutil.TempFile("", "testdiff")
if err != nil {
return nil, err
}
defer os.Remove(f2.Name())
defer f2.Close()
f1.Write(b1)
f2.Write(b2)
data, err = exec.Command("diff", "-u", f1.Name(), f2.Name()).CombinedOutput()
if len(data) > 0 {
// diff exits with a non-zero status when the files don't match.
// Ignore that failure as long as we get output.
err = nil
}
return
}
// tdiff logs the diff output to t.Error.
func tdiff(t *testing.T, a, b string) {
data, err := diff([]byte(a), []byte(b))
if err != nil {
t.Error(err)
return
}
t.Error(string(data))
}