func gofmt(fset *token.FileSet, filename string, src *bytes.Buffer) error {
f, _, _, err := format.Parse(fset, filename, src.Bytes(), false)
if err != nil {
return err
}
ast.SortImports(fset, f)
src.Reset()
return (&printer.Config{Mode: printerMode, Tabwidth: tabWidth}).Fprint(src, fset, f)
}
// Source formats src in canonical gofmt style and returns the result
// or an (I/O or syntax) error. src is expected to be a syntactically
// correct Go source file, or a list of Go declarations or statements.
//
// If src is a partial source file, the leading and trailing space of src
// is applied to the result (such that it has the same leading and trailing
// space as src), and the result is indented by the same amount as the first
// line of src containing code. Imports are not sorted for partial source files.
//
func Source(src []byte) ([]byte, error) {
fset := token.NewFileSet()
file, sourceAdj, indentAdj, err := format.Parse(fset, "", src, true)
if err != nil {
return nil, err
}
if sourceAdj == nil {
// Complete source file.
// TODO(gri) consider doing this always.
ast.SortImports(fset, file)
}
return format.Format(fset, file, sourceAdj, indentAdj, src, config)
}
func testFile(t *testing.T, b1, b2 *bytes.Buffer, filename string) {
// open file
f, err := os.Open(filename)
if err != nil {
t.Error(err)
return
}
// read file
b1.Reset()
_, err = io.Copy(b1, f)
f.Close()
if err != nil {
t.Error(err)
return
}
// exclude files w/ syntax errors (typically test cases)
fset := token.NewFileSet()
if _, _, _, err = format.Parse(fset, filename, b1.Bytes(), false); err != nil {
if *verbose {
fmt.Fprintf(os.Stderr, "ignoring %s\n", err)
}
return
}
// gofmt file
if err = gofmt(fset, filename, b1); err != nil {
t.Errorf("1st gofmt failed: %v", err)
return
}
// make a copy of the result
b2.Reset()
b2.Write(b1.Bytes())
// gofmt result again
if err = gofmt(fset, filename, b2); err != nil {
t.Errorf("2nd gofmt failed: %v", err)
return
}
// the first and 2nd result should be identical
if !bytes.Equal(b1.Bytes(), b2.Bytes()) {
t.Errorf("gofmt %s not idempotent", filename)
}
}
// If in == nil, the source is the contents of the file with the given filename.
func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error {
if in == nil {
f, err := os.Open(filename)
if err != nil {
return err
}
defer f.Close()
in = f
}
src, err := ioutil.ReadAll(in)
if err != nil {
return err
}
file, sourceAdj, indentAdj, err := format.Parse(fileSet, filename, src, stdin)
if err != nil {
return err
}
if rewrite != nil {
if sourceAdj == nil {
file = rewrite(file)
} else {
fmt.Fprintf(os.Stderr, "warning: rewrite ignored for incomplete programs\n")
}
}
ast.SortImports(fileSet, file)
if *simplifyAST {
simplify(file)
}
res, err := format.Format(fileSet, file, sourceAdj, indentAdj, src, printer.Config{Mode: printerMode, Tabwidth: tabWidth})
if err != nil {
return err
}
if !bytes.Equal(src, res) {
// formatting has changed
if *list {
fmt.Fprintln(out, filename)
}
if *write {
err = ioutil.WriteFile(filename, res, 0644)
if err != nil {
return err
}
}
if *doDiff {
data, err := diff(src, res)
if err != nil {
return fmt.Errorf("computing diff: %s", err)
}
fmt.Printf("diff %s gofmt/%s\n", filename, filename)
out.Write(data)
}
}
if !*list && !*write && !*doDiff {
_, err = out.Write(res)
}
return err
}