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// Copyright 2009 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 printer
import (
"bytes"
"flag"
"go/ast"
"go/parser"
"go/token"
"io/ioutil"
"path/filepath"
"testing"
"time"
)
const (
dataDir = "testdata"
tabwidth = 8
)
var update = flag.Bool("update", false, "update golden files")
var fset = token.NewFileSet()
func lineString(text []byte, i int) string {
i0 := i
for i < len(text) && text[i] != '\n' {
i++
}
return string(text[i0:i])
}
type checkMode uint
const (
export checkMode = 1 << iota
rawFormat
)
func runcheck(t *testing.T, source, golden string, mode checkMode) {
// parse source
prog, err := parser.ParseFile(fset, source, nil, parser.ParseComments)
if err != nil {
t.Error(err)
return
}
// filter exports if necessary
if mode&export != 0 {
ast.FileExports(prog) // ignore result
prog.Comments = nil // don't print comments that are not in AST
}
// determine printer configuration
cfg := Config{Tabwidth: tabwidth}
if mode&rawFormat != 0 {
cfg.Mode |= RawFormat
}
// format source
var buf bytes.Buffer
if err := cfg.Fprint(&buf, fset, prog); err != nil {
t.Error(err)
}
res := buf.Bytes()
// update golden files if necessary
if *update {
if err := ioutil.WriteFile(golden, res, 0644); err != nil {
t.Error(err)
}
return
}
// get golden
gld, err := ioutil.ReadFile(golden)
if err != nil {
t.Error(err)
return
}
// compare lengths
if len(res) != len(gld) {
t.Errorf("len = %d, expected %d (= len(%s))", len(res), len(gld), golden)
}
// compare contents
for i, line, offs := 0, 1, 0; i < len(res) && i < len(gld); i++ {
ch := res[i]
if ch != gld[i] {
t.Errorf("%s:%d:%d: %s", source, line, i-offs+1, lineString(res, offs))
t.Errorf("%s:%d:%d: %s", golden, line, i-offs+1, lineString(gld, offs))
t.Error()
return
}
if ch == '\n' {
line++
offs = i + 1
}
}
}
func check(t *testing.T, source, golden string, mode checkMode) {
// start a timer to produce a time-out signal
tc := make(chan int)
go func() {
time.Sleep(10e9) // plenty of a safety margin, even for very slow machines
tc <- 0
}()
// run the test
cc := make(chan int)
go func() {
runcheck(t, source, golden, mode)
cc <- 0
}()
// wait for the first finisher
select {
case <-tc:
// test running past time out
t.Errorf("%s: running too slowly", source)
case <-cc:
// test finished within alloted time margin
}
}
type entry struct {
source, golden string
mode checkMode
}
// Use gotest -update to create/update the respective golden files.
var data = []entry{
{"empty.input", "empty.golden", 0},
{"comments.input", "comments.golden", 0},
{"comments.input", "comments.x", export},
{"linebreaks.input", "linebreaks.golden", 0},
{"expressions.input", "expressions.golden", 0},
{"expressions.input", "expressions.raw", rawFormat},
{"declarations.input", "declarations.golden", 0},
{"statements.input", "statements.golden", 0},
{"slow.input", "slow.golden", 0},
}
func TestFiles(t *testing.T) {
for i, e := range data {
source := filepath.Join(dataDir, e.source)
golden := filepath.Join(dataDir, e.golden)
check(t, source, golden, e.mode)
// TODO(gri) check that golden is idempotent
//check(t, golden, golden, e.mode)
if testing.Short() && i >= 3 {
break
}
}
}
// TestLineComments, using a simple test case, checks that consequtive line
// comments are properly terminated with a newline even if the AST position
// information is incorrect.
//
func TestLineComments(t *testing.T) {
const src = `// comment 1
// comment 2
// comment 3
package main
`
fset := token.NewFileSet()
ast1, err1 := parser.ParseFile(fset, "", src, parser.ParseComments)
if err1 != nil {
panic(err1)
}
var buf bytes.Buffer
fset = token.NewFileSet() // use the wrong file set
Fprint(&buf, fset, ast1)
nlines := 0
for _, ch := range buf.Bytes() {
if ch == '\n' {
nlines++
}
}
const expected = 3
if nlines < expected {
t.Errorf("got %d, expected %d\n", nlines, expected)
}
}
// Verify that the printer can be invoked during initialization.
func init() {
const name = "foobar"
var buf bytes.Buffer
if err := Fprint(&buf, fset, &ast.Ident{Name: name}); err != nil {
panic(err)
}
if s := buf.String(); s != name {
panic("got " + s + ", want " + name)
}
}
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