Source file src/go/token/position_test.go

     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  
     5  package token
     6  
     7  import (
     8  	"fmt"
     9  	"math/rand"
    10  	"reflect"
    11  	"sync"
    12  	"testing"
    13  )
    14  
    15  func checkPos(t *testing.T, msg string, got, want Position) {
    16  	if got.Filename != want.Filename {
    17  		t.Errorf("%s: got filename = %q; want %q", msg, got.Filename, want.Filename)
    18  	}
    19  	if got.Offset != want.Offset {
    20  		t.Errorf("%s: got offset = %d; want %d", msg, got.Offset, want.Offset)
    21  	}
    22  	if got.Line != want.Line {
    23  		t.Errorf("%s: got line = %d; want %d", msg, got.Line, want.Line)
    24  	}
    25  	if got.Column != want.Column {
    26  		t.Errorf("%s: got column = %d; want %d", msg, got.Column, want.Column)
    27  	}
    28  }
    29  
    30  func TestNoPos(t *testing.T) {
    31  	if NoPos.IsValid() {
    32  		t.Errorf("NoPos should not be valid")
    33  	}
    34  	var fset *FileSet
    35  	checkPos(t, "nil NoPos", fset.Position(NoPos), Position{})
    36  	fset = NewFileSet()
    37  	checkPos(t, "fset NoPos", fset.Position(NoPos), Position{})
    38  }
    39  
    40  var tests = []struct {
    41  	filename string
    42  	source   []byte // may be nil
    43  	size     int
    44  	lines    []int
    45  }{
    46  	{"a", []byte{}, 0, []int{}},
    47  	{"b", []byte("01234"), 5, []int{0}},
    48  	{"c", []byte("\n\n\n\n\n\n\n\n\n"), 9, []int{0, 1, 2, 3, 4, 5, 6, 7, 8}},
    49  	{"d", nil, 100, []int{0, 5, 10, 20, 30, 70, 71, 72, 80, 85, 90, 99}},
    50  	{"e", nil, 777, []int{0, 80, 100, 120, 130, 180, 267, 455, 500, 567, 620}},
    51  	{"f", []byte("package p\n\nimport \"fmt\""), 23, []int{0, 10, 11}},
    52  	{"g", []byte("package p\n\nimport \"fmt\"\n"), 24, []int{0, 10, 11}},
    53  	{"h", []byte("package p\n\nimport \"fmt\"\n "), 25, []int{0, 10, 11, 24}},
    54  }
    55  
    56  func linecol(lines []int, offs int) (int, int) {
    57  	prevLineOffs := 0
    58  	for line, lineOffs := range lines {
    59  		if offs < lineOffs {
    60  			return line, offs - prevLineOffs + 1
    61  		}
    62  		prevLineOffs = lineOffs
    63  	}
    64  	return len(lines), offs - prevLineOffs + 1
    65  }
    66  
    67  func verifyPositions(t *testing.T, fset *FileSet, f *File, lines []int) {
    68  	for offs := 0; offs < f.Size(); offs++ {
    69  		p := f.Pos(offs)
    70  		offs2 := f.Offset(p)
    71  		if offs2 != offs {
    72  			t.Errorf("%s, Offset: got offset %d; want %d", f.Name(), offs2, offs)
    73  		}
    74  		line, col := linecol(lines, offs)
    75  		msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
    76  		checkPos(t, msg, f.Position(f.Pos(offs)), Position{f.Name(), offs, line, col})
    77  		checkPos(t, msg, fset.Position(p), Position{f.Name(), offs, line, col})
    78  	}
    79  }
    80  
    81  func makeTestSource(size int, lines []int) []byte {
    82  	src := make([]byte, size)
    83  	for _, offs := range lines {
    84  		if offs > 0 {
    85  			src[offs-1] = '\n'
    86  		}
    87  	}
    88  	return src
    89  }
    90  
    91  func TestPositions(t *testing.T) {
    92  	const delta = 7 // a non-zero base offset increment
    93  	fset := NewFileSet()
    94  	for _, test := range tests {
    95  		// verify consistency of test case
    96  		if test.source != nil && len(test.source) != test.size {
    97  			t.Errorf("%s: inconsistent test case: got file size %d; want %d", test.filename, len(test.source), test.size)
    98  		}
    99  
   100  		// add file and verify name and size
   101  		f := fset.AddFile(test.filename, fset.Base()+delta, test.size)
   102  		if f.Name() != test.filename {
   103  			t.Errorf("got filename %q; want %q", f.Name(), test.filename)
   104  		}
   105  		if f.Size() != test.size {
   106  			t.Errorf("%s: got file size %d; want %d", f.Name(), f.Size(), test.size)
   107  		}
   108  		if fset.File(f.Pos(0)) != f {
   109  			t.Errorf("%s: f.Pos(0) was not found in f", f.Name())
   110  		}
   111  
   112  		// add lines individually and verify all positions
   113  		for i, offset := range test.lines {
   114  			f.AddLine(offset)
   115  			if f.LineCount() != i+1 {
   116  				t.Errorf("%s, AddLine: got line count %d; want %d", f.Name(), f.LineCount(), i+1)
   117  			}
   118  			// adding the same offset again should be ignored
   119  			f.AddLine(offset)
   120  			if f.LineCount() != i+1 {
   121  				t.Errorf("%s, AddLine: got unchanged line count %d; want %d", f.Name(), f.LineCount(), i+1)
   122  			}
   123  			verifyPositions(t, fset, f, test.lines[0:i+1])
   124  		}
   125  
   126  		// add lines with SetLines and verify all positions
   127  		if ok := f.SetLines(test.lines); !ok {
   128  			t.Errorf("%s: SetLines failed", f.Name())
   129  		}
   130  		if f.LineCount() != len(test.lines) {
   131  			t.Errorf("%s, SetLines: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
   132  		}
   133  		if !reflect.DeepEqual(f.Lines(), test.lines) {
   134  			t.Errorf("%s, Lines after SetLines(v): got %v; want %v", f.Name(), f.Lines(), test.lines)
   135  		}
   136  		verifyPositions(t, fset, f, test.lines)
   137  
   138  		// add lines with SetLinesForContent and verify all positions
   139  		src := test.source
   140  		if src == nil {
   141  			// no test source available - create one from scratch
   142  			src = makeTestSource(test.size, test.lines)
   143  		}
   144  		f.SetLinesForContent(src)
   145  		if f.LineCount() != len(test.lines) {
   146  			t.Errorf("%s, SetLinesForContent: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
   147  		}
   148  		verifyPositions(t, fset, f, test.lines)
   149  	}
   150  }
   151  
   152  func TestLineInfo(t *testing.T) {
   153  	fset := NewFileSet()
   154  	f := fset.AddFile("foo", fset.Base(), 500)
   155  	lines := []int{0, 42, 77, 100, 210, 220, 277, 300, 333, 401}
   156  	// add lines individually and provide alternative line information
   157  	for _, offs := range lines {
   158  		f.AddLine(offs)
   159  		f.AddLineInfo(offs, "bar", 42)
   160  	}
   161  	// verify positions for all offsets
   162  	for offs := 0; offs <= f.Size(); offs++ {
   163  		p := f.Pos(offs)
   164  		_, col := linecol(lines, offs)
   165  		msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
   166  		checkPos(t, msg, f.Position(f.Pos(offs)), Position{"bar", offs, 42, col})
   167  		checkPos(t, msg, fset.Position(p), Position{"bar", offs, 42, col})
   168  	}
   169  }
   170  
   171  func TestFiles(t *testing.T) {
   172  	fset := NewFileSet()
   173  	for i, test := range tests {
   174  		base := fset.Base()
   175  		if i%2 == 1 {
   176  			// Setting a negative base is equivalent to
   177  			// fset.Base(), so test some of each.
   178  			base = -1
   179  		}
   180  		fset.AddFile(test.filename, base, test.size)
   181  		j := 0
   182  		fset.Iterate(func(f *File) bool {
   183  			if f.Name() != tests[j].filename {
   184  				t.Errorf("got filename = %s; want %s", f.Name(), tests[j].filename)
   185  			}
   186  			j++
   187  			return true
   188  		})
   189  		if j != i+1 {
   190  			t.Errorf("got %d files; want %d", j, i+1)
   191  		}
   192  	}
   193  }
   194  
   195  // FileSet.File should return nil if Pos is past the end of the FileSet.
   196  func TestFileSetPastEnd(t *testing.T) {
   197  	fset := NewFileSet()
   198  	for _, test := range tests {
   199  		fset.AddFile(test.filename, fset.Base(), test.size)
   200  	}
   201  	if f := fset.File(Pos(fset.Base())); f != nil {
   202  		t.Errorf("got %v, want nil", f)
   203  	}
   204  }
   205  
   206  func TestFileSetCacheUnlikely(t *testing.T) {
   207  	fset := NewFileSet()
   208  	offsets := make(map[string]int)
   209  	for _, test := range tests {
   210  		offsets[test.filename] = fset.Base()
   211  		fset.AddFile(test.filename, fset.Base(), test.size)
   212  	}
   213  	for file, pos := range offsets {
   214  		f := fset.File(Pos(pos))
   215  		if f.Name() != file {
   216  			t.Errorf("got %q at position %d, want %q", f.Name(), pos, file)
   217  		}
   218  	}
   219  }
   220  
   221  // issue 4345. Test that concurrent use of FileSet.Pos does not trigger a
   222  // race in the FileSet position cache.
   223  func TestFileSetRace(t *testing.T) {
   224  	fset := NewFileSet()
   225  	for i := 0; i < 100; i++ {
   226  		fset.AddFile(fmt.Sprintf("file-%d", i), fset.Base(), 1031)
   227  	}
   228  	max := int32(fset.Base())
   229  	var stop sync.WaitGroup
   230  	r := rand.New(rand.NewSource(7))
   231  	for i := 0; i < 2; i++ {
   232  		r := rand.New(rand.NewSource(r.Int63()))
   233  		stop.Add(1)
   234  		go func() {
   235  			for i := 0; i < 1000; i++ {
   236  				fset.Position(Pos(r.Int31n(max)))
   237  			}
   238  			stop.Done()
   239  		}()
   240  	}
   241  	stop.Wait()
   242  }
   243  
   244  // issue 16548. Test that concurrent use of File.AddLine and FileSet.PositionFor
   245  // does not trigger a race in the FileSet position cache.
   246  func TestFileSetRace2(t *testing.T) {
   247  	const N = 1e3
   248  	var (
   249  		fset = NewFileSet()
   250  		file = fset.AddFile("", -1, N)
   251  		ch   = make(chan int, 2)
   252  	)
   253  
   254  	go func() {
   255  		for i := 0; i < N; i++ {
   256  			file.AddLine(i)
   257  		}
   258  		ch <- 1
   259  	}()
   260  
   261  	go func() {
   262  		pos := file.Pos(0)
   263  		for i := 0; i < N; i++ {
   264  			fset.PositionFor(pos, false)
   265  		}
   266  		ch <- 1
   267  	}()
   268  
   269  	<-ch
   270  	<-ch
   271  }
   272  
   273  func TestPositionFor(t *testing.T) {
   274  	src := []byte(`
   275  foo
   276  b
   277  ar
   278  //line :100
   279  foobar
   280  //line bar:3
   281  done
   282  `)
   283  
   284  	const filename = "foo"
   285  	fset := NewFileSet()
   286  	f := fset.AddFile(filename, fset.Base(), len(src))
   287  	f.SetLinesForContent(src)
   288  
   289  	// verify position info
   290  	for i, offs := range f.lines {
   291  		got1 := f.PositionFor(f.Pos(offs), false)
   292  		got2 := f.PositionFor(f.Pos(offs), true)
   293  		got3 := f.Position(f.Pos(offs))
   294  		want := Position{filename, offs, i + 1, 1}
   295  		checkPos(t, "1. PositionFor unadjusted", got1, want)
   296  		checkPos(t, "1. PositionFor adjusted", got2, want)
   297  		checkPos(t, "1. Position", got3, want)
   298  	}
   299  
   300  	// manually add //line info on lines l1, l2
   301  	const l1, l2 = 5, 7
   302  	f.AddLineInfo(f.lines[l1-1], "", 100)
   303  	f.AddLineInfo(f.lines[l2-1], "bar", 3)
   304  
   305  	// unadjusted position info must remain unchanged
   306  	for i, offs := range f.lines {
   307  		got1 := f.PositionFor(f.Pos(offs), false)
   308  		want := Position{filename, offs, i + 1, 1}
   309  		checkPos(t, "2. PositionFor unadjusted", got1, want)
   310  	}
   311  
   312  	// adjusted position info should have changed
   313  	for i, offs := range f.lines {
   314  		got2 := f.PositionFor(f.Pos(offs), true)
   315  		got3 := f.Position(f.Pos(offs))
   316  		want := Position{filename, offs, i + 1, 1}
   317  		// manually compute wanted filename and line
   318  		line := want.Line
   319  		if i+1 >= l1 {
   320  			want.Filename = ""
   321  			want.Line = line - l1 + 100
   322  		}
   323  		if i+1 >= l2 {
   324  			want.Filename = "bar"
   325  			want.Line = line - l2 + 3
   326  		}
   327  		checkPos(t, "3. PositionFor adjusted", got2, want)
   328  		checkPos(t, "3. Position", got3, want)
   329  	}
   330  }
   331  
   332  func TestLineStart(t *testing.T) {
   333  	const src = "one\ntwo\nthree\n"
   334  	fset := NewFileSet()
   335  	f := fset.AddFile("input", -1, len(src))
   336  	f.SetLinesForContent([]byte(src))
   337  
   338  	for line := 1; line <= 3; line++ {
   339  		pos := f.LineStart(line)
   340  		position := fset.Position(pos)
   341  		if position.Line != line || position.Column != 1 {
   342  			t.Errorf("LineStart(%d) returned wrong pos %d: %s", line, pos, position)
   343  		}
   344  	}
   345  }
   346  
   347  func TestRemoveFile(t *testing.T) {
   348  	contentA := []byte("this\nis\nfileA")
   349  	contentB := []byte("this\nis\nfileB")
   350  	fset := NewFileSet()
   351  	a := fset.AddFile("fileA", -1, len(contentA))
   352  	a.SetLinesForContent(contentA)
   353  	b := fset.AddFile("fileB", -1, len(contentB))
   354  	b.SetLinesForContent(contentB)
   355  
   356  	checkPos := func(pos Pos, want string) {
   357  		if got := fset.Position(pos).String(); got != want {
   358  			t.Errorf("Position(%d) = %s, want %s", pos, got, want)
   359  		}
   360  	}
   361  	checkNumFiles := func(want int) {
   362  		got := 0
   363  		fset.Iterate(func(*File) bool { got++; return true })
   364  		if got != want {
   365  			t.Errorf("Iterate called %d times, want %d", got, want)
   366  		}
   367  	}
   368  
   369  	apos3 := a.Pos(3)
   370  	bpos3 := b.Pos(3)
   371  	checkPos(apos3, "fileA:1:4")
   372  	checkPos(bpos3, "fileB:1:4")
   373  	checkNumFiles(2)
   374  
   375  	// After removal, queries on fileA fail.
   376  	fset.RemoveFile(a)
   377  	checkPos(apos3, "-")
   378  	checkPos(bpos3, "fileB:1:4")
   379  	checkNumFiles(1)
   380  
   381  	// idempotent / no effect
   382  	fset.RemoveFile(a)
   383  	checkPos(apos3, "-")
   384  	checkPos(bpos3, "fileB:1:4")
   385  	checkNumFiles(1)
   386  }
   387  
   388  func TestFileAddLineColumnInfo(t *testing.T) {
   389  	const (
   390  		filename = "test.go"
   391  		filesize = 100
   392  	)
   393  
   394  	tests := []struct {
   395  		name  string
   396  		infos []lineInfo
   397  		want  []lineInfo
   398  	}{
   399  		{
   400  			name: "normal",
   401  			infos: []lineInfo{
   402  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   403  				{Offset: 50, Filename: filename, Line: 3, Column: 1},
   404  				{Offset: 80, Filename: filename, Line: 4, Column: 2},
   405  			},
   406  			want: []lineInfo{
   407  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   408  				{Offset: 50, Filename: filename, Line: 3, Column: 1},
   409  				{Offset: 80, Filename: filename, Line: 4, Column: 2},
   410  			},
   411  		},
   412  		{
   413  			name: "offset1 == file size",
   414  			infos: []lineInfo{
   415  				{Offset: filesize, Filename: filename, Line: 2, Column: 1},
   416  			},
   417  			want: nil,
   418  		},
   419  		{
   420  			name: "offset1 > file size",
   421  			infos: []lineInfo{
   422  				{Offset: filesize + 1, Filename: filename, Line: 2, Column: 1},
   423  			},
   424  			want: nil,
   425  		},
   426  		{
   427  			name: "offset2 == file size",
   428  			infos: []lineInfo{
   429  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   430  				{Offset: filesize, Filename: filename, Line: 3, Column: 1},
   431  			},
   432  			want: []lineInfo{
   433  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   434  			},
   435  		},
   436  		{
   437  			name: "offset2 > file size",
   438  			infos: []lineInfo{
   439  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   440  				{Offset: filesize + 1, Filename: filename, Line: 3, Column: 1},
   441  			},
   442  			want: []lineInfo{
   443  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   444  			},
   445  		},
   446  		{
   447  			name: "offset2 == offset1",
   448  			infos: []lineInfo{
   449  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   450  				{Offset: 10, Filename: filename, Line: 3, Column: 1},
   451  			},
   452  			want: []lineInfo{
   453  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   454  			},
   455  		},
   456  		{
   457  			name: "offset2 < offset1",
   458  			infos: []lineInfo{
   459  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   460  				{Offset: 9, Filename: filename, Line: 3, Column: 1},
   461  			},
   462  			want: []lineInfo{
   463  				{Offset: 10, Filename: filename, Line: 2, Column: 1},
   464  			},
   465  		},
   466  	}
   467  
   468  	for _, test := range tests {
   469  		t.Run(test.name, func(t *testing.T) {
   470  			fs := NewFileSet()
   471  			f := fs.AddFile(filename, -1, filesize)
   472  			for _, info := range test.infos {
   473  				f.AddLineColumnInfo(info.Offset, info.Filename, info.Line, info.Column)
   474  			}
   475  			if !reflect.DeepEqual(f.infos, test.want) {
   476  				t.Errorf("\ngot %+v, \nwant %+v", f.infos, test.want)
   477  			}
   478  		})
   479  	}
   480  }
   481  
   482  func TestIssue57490(t *testing.T) {
   483  	// If debug is set, this test is expected to panic.
   484  	if debug {
   485  		defer func() {
   486  			if recover() == nil {
   487  				t.Errorf("got no panic")
   488  			}
   489  		}()
   490  	}
   491  
   492  	const fsize = 5
   493  	fset := NewFileSet()
   494  	base := fset.Base()
   495  	f := fset.AddFile("f", base, fsize)
   496  
   497  	// out-of-bounds positions must not lead to a panic when calling f.Offset
   498  	if got := f.Offset(NoPos); got != 0 {
   499  		t.Errorf("offset = %d, want %d", got, 0)
   500  	}
   501  	if got := f.Offset(Pos(-1)); got != 0 {
   502  		t.Errorf("offset = %d, want %d", got, 0)
   503  	}
   504  	if got := f.Offset(Pos(base + fsize + 1)); got != fsize {
   505  		t.Errorf("offset = %d, want %d", got, fsize)
   506  	}
   507  
   508  	// out-of-bounds offsets must not lead to a panic when calling f.Pos
   509  	if got := f.Pos(-1); got != Pos(base) {
   510  		t.Errorf("pos = %d, want %d", got, base)
   511  	}
   512  	if got := f.Pos(fsize + 1); got != Pos(base+fsize) {
   513  		t.Errorf("pos = %d, want %d", got, base+fsize)
   514  	}
   515  
   516  	// out-of-bounds Pos values must not lead to a panic when calling f.Position
   517  	want := fmt.Sprintf("%s:1:1", f.Name())
   518  	if got := f.Position(Pos(-1)).String(); got != want {
   519  		t.Errorf("position = %s, want %s", got, want)
   520  	}
   521  	want = fmt.Sprintf("%s:1:%d", f.Name(), fsize+1)
   522  	if got := f.Position(Pos(fsize + 1)).String(); got != want {
   523  		t.Errorf("position = %s, want %s", got, want)
   524  	}
   525  
   526  	// check invariants
   527  	const xsize = fsize + 5
   528  	for offset := -xsize; offset < xsize; offset++ {
   529  		want1 := f.Offset(Pos(f.base + offset))
   530  		if got := f.Offset(f.Pos(offset)); got != want1 {
   531  			t.Errorf("offset = %d, want %d", got, want1)
   532  		}
   533  
   534  		want2 := f.Pos(offset)
   535  		if got := f.Pos(f.Offset(want2)); got != want2 {
   536  			t.Errorf("pos = %d, want %d", got, want2)
   537  		}
   538  	}
   539  }
   540  

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