1// Copyright 2010 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package token
6
7import (
8	"fmt"
9	"math/rand"
10	"sync"
11	"testing"
12)
13
14func checkPos(t *testing.T, msg string, got, want Position) {
15	if got.Filename != want.Filename {
16		t.Errorf("%s: got filename = %q; want %q", msg, got.Filename, want.Filename)
17	}
18	if got.Offset != want.Offset {
19		t.Errorf("%s: got offset = %d; want %d", msg, got.Offset, want.Offset)
20	}
21	if got.Line != want.Line {
22		t.Errorf("%s: got line = %d; want %d", msg, got.Line, want.Line)
23	}
24	if got.Column != want.Column {
25		t.Errorf("%s: got column = %d; want %d", msg, got.Column, want.Column)
26	}
27}
28
29func TestNoPos(t *testing.T) {
30	if NoPos.IsValid() {
31		t.Errorf("NoPos should not be valid")
32	}
33	var fset *FileSet
34	checkPos(t, "nil NoPos", fset.Position(NoPos), Position{})
35	fset = NewFileSet()
36	checkPos(t, "fset NoPos", fset.Position(NoPos), Position{})
37}
38
39var tests = []struct {
40	filename string
41	source   []byte // may be nil
42	size     int
43	lines    []int
44}{
45	{"a", []byte{}, 0, []int{}},
46	{"b", []byte("01234"), 5, []int{0}},
47	{"c", []byte("\n\n\n\n\n\n\n\n\n"), 9, []int{0, 1, 2, 3, 4, 5, 6, 7, 8}},
48	{"d", nil, 100, []int{0, 5, 10, 20, 30, 70, 71, 72, 80, 85, 90, 99}},
49	{"e", nil, 777, []int{0, 80, 100, 120, 130, 180, 267, 455, 500, 567, 620}},
50	{"f", []byte("package p\n\nimport \"fmt\""), 23, []int{0, 10, 11}},
51	{"g", []byte("package p\n\nimport \"fmt\"\n"), 24, []int{0, 10, 11}},
52	{"h", []byte("package p\n\nimport \"fmt\"\n "), 25, []int{0, 10, 11, 24}},
53}
54
55func linecol(lines []int, offs int) (int, int) {
56	prevLineOffs := 0
57	for line, lineOffs := range lines {
58		if offs < lineOffs {
59			return line, offs - prevLineOffs + 1
60		}
61		prevLineOffs = lineOffs
62	}
63	return len(lines), offs - prevLineOffs + 1
64}
65
66func verifyPositions(t *testing.T, fset *FileSet, f *File, lines []int) {
67	for offs := 0; offs < f.Size(); offs++ {
68		p := f.Pos(offs)
69		offs2 := f.Offset(p)
70		if offs2 != offs {
71			t.Errorf("%s, Offset: got offset %d; want %d", f.Name(), offs2, offs)
72		}
73		line, col := linecol(lines, offs)
74		msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
75		checkPos(t, msg, f.Position(f.Pos(offs)), Position{f.Name(), offs, line, col})
76		checkPos(t, msg, fset.Position(p), Position{f.Name(), offs, line, col})
77	}
78}
79
80func makeTestSource(size int, lines []int) []byte {
81	src := make([]byte, size)
82	for _, offs := range lines {
83		if offs > 0 {
84			src[offs-1] = '\n'
85		}
86	}
87	return src
88}
89
90func TestPositions(t *testing.T) {
91	const delta = 7 // a non-zero base offset increment
92	fset := NewFileSet()
93	for _, test := range tests {
94		// verify consistency of test case
95		if test.source != nil && len(test.source) != test.size {
96			t.Errorf("%s: inconsistent test case: got file size %d; want %d", test.filename, len(test.source), test.size)
97		}
98
99		// add file and verify name and size
100		f := fset.AddFile(test.filename, fset.Base()+delta, test.size)
101		if f.Name() != test.filename {
102			t.Errorf("got filename %q; want %q", f.Name(), test.filename)
103		}
104		if f.Size() != test.size {
105			t.Errorf("%s: got file size %d; want %d", f.Name(), f.Size(), test.size)
106		}
107		if fset.File(f.Pos(0)) != f {
108			t.Errorf("%s: f.Pos(0) was not found in f", f.Name())
109		}
110
111		// add lines individually and verify all positions
112		for i, offset := range test.lines {
113			f.AddLine(offset)
114			if f.LineCount() != i+1 {
115				t.Errorf("%s, AddLine: got line count %d; want %d", f.Name(), f.LineCount(), i+1)
116			}
117			// adding the same offset again should be ignored
118			f.AddLine(offset)
119			if f.LineCount() != i+1 {
120				t.Errorf("%s, AddLine: got unchanged line count %d; want %d", f.Name(), f.LineCount(), i+1)
121			}
122			verifyPositions(t, fset, f, test.lines[0:i+1])
123		}
124
125		// add lines with SetLines and verify all positions
126		if ok := f.SetLines(test.lines); !ok {
127			t.Errorf("%s: SetLines failed", f.Name())
128		}
129		if f.LineCount() != len(test.lines) {
130			t.Errorf("%s, SetLines: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
131		}
132		verifyPositions(t, fset, f, test.lines)
133
134		// add lines with SetLinesForContent and verify all positions
135		src := test.source
136		if src == nil {
137			// no test source available - create one from scratch
138			src = makeTestSource(test.size, test.lines)
139		}
140		f.SetLinesForContent(src)
141		if f.LineCount() != len(test.lines) {
142			t.Errorf("%s, SetLinesForContent: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
143		}
144		verifyPositions(t, fset, f, test.lines)
145	}
146}
147
148func TestLineInfo(t *testing.T) {
149	fset := NewFileSet()
150	f := fset.AddFile("foo", fset.Base(), 500)
151	lines := []int{0, 42, 77, 100, 210, 220, 277, 300, 333, 401}
152	// add lines individually and provide alternative line information
153	for _, offs := range lines {
154		f.AddLine(offs)
155		f.AddLineInfo(offs, "bar", 42)
156	}
157	// verify positions for all offsets
158	for offs := 0; offs <= f.Size(); offs++ {
159		p := f.Pos(offs)
160		_, col := linecol(lines, offs)
161		msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
162		checkPos(t, msg, f.Position(f.Pos(offs)), Position{"bar", offs, 42, col})
163		checkPos(t, msg, fset.Position(p), Position{"bar", offs, 42, col})
164	}
165}
166
167func TestFiles(t *testing.T) {
168	fset := NewFileSet()
169	for i, test := range tests {
170		base := fset.Base()
171		if i%2 == 1 {
172			// Setting a negative base is equivalent to
173			// fset.Base(), so test some of each.
174			base = -1
175		}
176		fset.AddFile(test.filename, base, test.size)
177		j := 0
178		fset.Iterate(func(f *File) bool {
179			if f.Name() != tests[j].filename {
180				t.Errorf("got filename = %s; want %s", f.Name(), tests[j].filename)
181			}
182			j++
183			return true
184		})
185		if j != i+1 {
186			t.Errorf("got %d files; want %d", j, i+1)
187		}
188	}
189}
190
191// FileSet.File should return nil if Pos is past the end of the FileSet.
192func TestFileSetPastEnd(t *testing.T) {
193	fset := NewFileSet()
194	for _, test := range tests {
195		fset.AddFile(test.filename, fset.Base(), test.size)
196	}
197	if f := fset.File(Pos(fset.Base())); f != nil {
198		t.Errorf("got %v, want nil", f)
199	}
200}
201
202func TestFileSetCacheUnlikely(t *testing.T) {
203	fset := NewFileSet()
204	offsets := make(map[string]int)
205	for _, test := range tests {
206		offsets[test.filename] = fset.Base()
207		fset.AddFile(test.filename, fset.Base(), test.size)
208	}
209	for file, pos := range offsets {
210		f := fset.File(Pos(pos))
211		if f.Name() != file {
212			t.Errorf("got %q at position %d, want %q", f.Name(), pos, file)
213		}
214	}
215}
216
217// issue 4345. Test that concurrent use of FileSet.Pos does not trigger a
218// race in the FileSet position cache.
219func TestFileSetRace(t *testing.T) {
220	fset := NewFileSet()
221	for i := 0; i < 100; i++ {
222		fset.AddFile(fmt.Sprintf("file-%d", i), fset.Base(), 1031)
223	}
224	max := int32(fset.Base())
225	var stop sync.WaitGroup
226	r := rand.New(rand.NewSource(7))
227	for i := 0; i < 2; i++ {
228		r := rand.New(rand.NewSource(r.Int63()))
229		stop.Add(1)
230		go func() {
231			for i := 0; i < 1000; i++ {
232				fset.Position(Pos(r.Int31n(max)))
233			}
234			stop.Done()
235		}()
236	}
237	stop.Wait()
238}
239
240// issue 16548. Test that concurrent use of File.AddLine and FileSet.PositionFor
241// does not trigger a race in the FileSet position cache.
242func TestFileSetRace2(t *testing.T) {
243	const N = 1e3
244	var (
245		fset = NewFileSet()
246		file = fset.AddFile("", -1, N)
247		ch   = make(chan int, 2)
248	)
249
250	go func() {
251		for i := 0; i < N; i++ {
252			file.AddLine(i)
253		}
254		ch <- 1
255	}()
256
257	go func() {
258		pos := file.Pos(0)
259		for i := 0; i < N; i++ {
260			fset.PositionFor(pos, false)
261		}
262		ch <- 1
263	}()
264
265	<-ch
266	<-ch
267}
268
269func TestPositionFor(t *testing.T) {
270	src := []byte(`
271foo
272b
273ar
274//line :100
275foobar
276//line bar:3
277done
278`)
279
280	const filename = "foo"
281	fset := NewFileSet()
282	f := fset.AddFile(filename, fset.Base(), len(src))
283	f.SetLinesForContent(src)
284
285	// verify position info
286	for i, offs := range f.lines {
287		got1 := f.PositionFor(f.Pos(offs), false)
288		got2 := f.PositionFor(f.Pos(offs), true)
289		got3 := f.Position(f.Pos(offs))
290		want := Position{filename, offs, i + 1, 1}
291		checkPos(t, "1. PositionFor unadjusted", got1, want)
292		checkPos(t, "1. PositionFor adjusted", got2, want)
293		checkPos(t, "1. Position", got3, want)
294	}
295
296	// manually add //line info on lines l1, l2
297	const l1, l2 = 5, 7
298	f.AddLineInfo(f.lines[l1-1], "", 100)
299	f.AddLineInfo(f.lines[l2-1], "bar", 3)
300
301	// unadjusted position info must remain unchanged
302	for i, offs := range f.lines {
303		got1 := f.PositionFor(f.Pos(offs), false)
304		want := Position{filename, offs, i + 1, 1}
305		checkPos(t, "2. PositionFor unadjusted", got1, want)
306	}
307
308	// adjusted position info should have changed
309	for i, offs := range f.lines {
310		got2 := f.PositionFor(f.Pos(offs), true)
311		got3 := f.Position(f.Pos(offs))
312		want := Position{filename, offs, i + 1, 1}
313		// manually compute wanted filename and line
314		line := want.Line
315		if i+1 >= l1 {
316			want.Filename = ""
317			want.Line = line - l1 + 100
318		}
319		if i+1 >= l2 {
320			want.Filename = "bar"
321			want.Line = line - l2 + 3
322		}
323		checkPos(t, "3. PositionFor adjusted", got2, want)
324		checkPos(t, "3. Position", got3, want)
325	}
326}
327
328func TestLineStart(t *testing.T) {
329	const src = "one\ntwo\nthree\n"
330	fset := NewFileSet()
331	f := fset.AddFile("input", -1, len(src))
332	f.SetLinesForContent([]byte(src))
333
334	for line := 1; line <= 3; line++ {
335		pos := f.LineStart(line)
336		position := fset.Position(pos)
337		if position.Line != line || position.Column != 1 {
338			t.Errorf("LineStart(%d) returned wrong pos %d: %s", line, pos, position)
339		}
340	}
341}
342