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author | Tianon Gravi <admwiggin@gmail.com> | 2015-01-15 12:50:40 -0700 |
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committer | Tianon Gravi <admwiggin@gmail.com> | 2015-01-15 12:50:40 -0700 |
commit | 2a0db60599fdd75b1bc3e297180fbe1282763759 (patch) | |
tree | 68d43c3e30d9ab961ddf6b7365201ca6b675b253 /src/go/parser/error_test.go | |
parent | ef33cba3c8de6c431df56503df51fcd3a473c89e (diff) | |
parent | f154da9e12608589e8d5f0508f908a0c3e88a1bb (diff) | |
download | golang-2a0db60599fdd75b1bc3e297180fbe1282763759.tar.gz |
Merge tag 'upstream/1.4' into debian-experimental
* tag 'upstream/1.4':
Imported Upstream version 1.4
Diffstat (limited to 'src/go/parser/error_test.go')
-rw-r--r-- | src/go/parser/error_test.go | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/go/parser/error_test.go b/src/go/parser/error_test.go new file mode 100644 index 000000000..48fb53e5b --- /dev/null +++ b/src/go/parser/error_test.go @@ -0,0 +1,182 @@ +// Copyright 2012 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. + +// This file implements a parser test harness. The files in the testdata +// directory are parsed and the errors reported are compared against the +// error messages expected in the test files. The test files must end in +// .src rather than .go so that they are not disturbed by gofmt runs. +// +// Expected errors are indicated in the test files by putting a comment +// of the form /* ERROR "rx" */ immediately following an offending token. +// The harness will verify that an error matching the regular expression +// rx is reported at that source position. +// +// For instance, the following test file indicates that a "not declared" +// error should be reported for the undeclared variable x: +// +// package p +// func f() { +// _ = x /* ERROR "not declared" */ + 1 +// } + +package parser + +import ( + "go/scanner" + "go/token" + "io/ioutil" + "path/filepath" + "regexp" + "strings" + "testing" +) + +const testdata = "testdata" + +var fsetErrs = token.NewFileSet() + +// getFile assumes that each filename occurs at most once +func getFile(filename string) (file *token.File) { + fsetErrs.Iterate(func(f *token.File) bool { + if f.Name() == filename { + if file != nil { + panic(filename + " used multiple times") + } + file = f + } + return true + }) + return file +} + +func getPos(filename string, offset int) token.Pos { + if f := getFile(filename); f != nil { + return f.Pos(offset) + } + return token.NoPos +} + +// ERROR comments must be of the form /* ERROR "rx" */ and rx is +// a regular expression that matches the expected error message. +// The special form /* ERROR HERE "rx" */ must be used for error +// messages that appear immediately after a token, rather than at +// a token's position. +// +var errRx = regexp.MustCompile(`^/\* *ERROR *(HERE)? *"([^"]*)" *\*/$`) + +// expectedErrors collects the regular expressions of ERROR comments found +// in files and returns them as a map of error positions to error messages. +// +func expectedErrors(t *testing.T, filename string, src []byte) map[token.Pos]string { + errors := make(map[token.Pos]string) + + var s scanner.Scanner + // file was parsed already - do not add it again to the file + // set otherwise the position information returned here will + // not match the position information collected by the parser + s.Init(getFile(filename), src, nil, scanner.ScanComments) + var prev token.Pos // position of last non-comment, non-semicolon token + var here token.Pos // position immediately after the token at position prev + + for { + pos, tok, lit := s.Scan() + switch tok { + case token.EOF: + return errors + case token.COMMENT: + s := errRx.FindStringSubmatch(lit) + if len(s) == 3 { + pos := prev + if s[1] == "HERE" { + pos = here + } + errors[pos] = string(s[2]) + } + default: + prev = pos + var l int // token length + if tok.IsLiteral() { + l = len(lit) + } else { + l = len(tok.String()) + } + here = prev + token.Pos(l) + } + } +} + +// compareErrors compares the map of expected error messages with the list +// of found errors and reports discrepancies. +// +func compareErrors(t *testing.T, expected map[token.Pos]string, found scanner.ErrorList) { + for _, error := range found { + // error.Pos is a token.Position, but we want + // a token.Pos so we can do a map lookup + pos := getPos(error.Pos.Filename, error.Pos.Offset) + if msg, found := expected[pos]; found { + // we expect a message at pos; check if it matches + rx, err := regexp.Compile(msg) + if err != nil { + t.Errorf("%s: %v", error.Pos, err) + continue + } + if match := rx.MatchString(error.Msg); !match { + t.Errorf("%s: %q does not match %q", error.Pos, error.Msg, msg) + continue + } + // we have a match - eliminate this error + delete(expected, pos) + } else { + // To keep in mind when analyzing failed test output: + // If the same error position occurs multiple times in errors, + // this message will be triggered (because the first error at + // the position removes this position from the expected errors). + t.Errorf("%s: unexpected error: %s", error.Pos, error.Msg) + } + } + + // there should be no expected errors left + if len(expected) > 0 { + t.Errorf("%d errors not reported:", len(expected)) + for pos, msg := range expected { + t.Errorf("%s: %s\n", fsetErrs.Position(pos), msg) + } + } +} + +func checkErrors(t *testing.T, filename string, input interface{}) { + src, err := readSource(filename, input) + if err != nil { + t.Error(err) + return + } + + _, err = ParseFile(fsetErrs, filename, src, DeclarationErrors|AllErrors) + found, ok := err.(scanner.ErrorList) + if err != nil && !ok { + t.Error(err) + return + } + found.RemoveMultiples() + + // we are expecting the following errors + // (collect these after parsing a file so that it is found in the file set) + expected := expectedErrors(t, filename, src) + + // verify errors returned by the parser + compareErrors(t, expected, found) +} + +func TestErrors(t *testing.T) { + list, err := ioutil.ReadDir(testdata) + if err != nil { + t.Fatal(err) + } + for _, fi := range list { + name := fi.Name() + if !fi.IsDir() && !strings.HasPrefix(name, ".") && strings.HasSuffix(name, ".src") { + checkErrors(t, filepath.Join(testdata, name), nil) + } + } +} |