func TestLeadAndLineComments(t *testing.T) {
f, err := ParseFile(fset, "", `
package p
type T struct {
/* F1 lead comment */
//
F1 int /* F1 */ // line comment
// F2 lead
// comment
F2 int // F2 line comment
// f3 lead comment
f3 int // f3 line comment
}
`, ParseComments)
if err != nil {
t.Fatal(err)
}
checkFieldComments(t, f, "T.F1", "/* F1 lead comment *///", "/* F1 */// line comment")
checkFieldComments(t, f, "T.F2", "// F2 lead// comment", "// F2 line comment")
checkFieldComments(t, f, "T.f3", "// f3 lead comment", "// f3 line comment")
ast.FileExports(f)
checkFieldComments(t, f, "T.F1", "/* F1 lead comment *///", "/* F1 */// line comment")
checkFieldComments(t, f, "T.F2", "// F2 lead// comment", "// F2 line comment")
if getField(f, "T.f3") != nil {
t.Error("not expected to find T.f3")
}
}
// format parses src, prints the corresponding AST, verifies the resulting
// src is syntactically correct, and returns the resulting src or an error
// if any.
func format(src []byte, mode checkMode) ([]byte, error) {
// parse src
f, err := parser.ParseFile(fset, "", src, parser.ParseComments)
if err != nil {
return nil, fmt.Errorf("parse: %s\n%s", err, src)
}
// filter exports if necessary
if mode&export != 0 {
ast.FileExports(f) // ignore result
f.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
}
// print AST
var buf bytes.Buffer
if err := cfg.Fprint(&buf, fset, f); err != nil {
return nil, fmt.Errorf("print: %s", err)
}
// make sure formatted output is syntactically correct
res := buf.Bytes()
if _, err := parser.ParseFile(fset, "", res, 0); err != nil {
return nil, fmt.Errorf("re-parse: %s\n%s", err, buf.Bytes())
}
return res, nil
}
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()
// formatted source must be valid
if _, err := parser.ParseFile(fset, "", res, 0); err != nil {
t.Error(err)
t.Logf("\n%s", res)
return
}
// 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
}
}
}