gopls/internal/diff/diff

1	// Copyright 2019 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 diff_test
6
7	import (
8	"math/rand"
9	"reflect"
10	"testing"
11	"unicode/utf8"
12
13	"golang.org/x/tools/internal/diff"
14	"golang.org/x/tools/internal/diff/difftest"
15	)
16
17	func TestApply(t *testing.T) {
18	for _, tc := range difftest.TestCases {
19	t.Run(tc.Name, func(t *testing.T) {
20	got, err := diff.Apply(tc.In, tc.Edits)
21	if err != nil {
22	t.Fatalf("Apply(Edits) failed: %v", err)
23	}
24	if got != tc.Out {
25	t.Errorf("Apply(Edits): got %q, want %q", got, tc.Out)
26	}
27	if tc.LineEdits != nil {
28	got, err := diff.Apply(tc.In, tc.LineEdits)
29	if err != nil {
30	t.Fatalf("Apply(LineEdits) failed: %v", err)
31	}
32	if got != tc.Out {
33	t.Errorf("Apply(LineEdits): got %q, want %q", got, tc.Out)
34	}
35	}
36	})
37	}
38	}
39
40	func TestNEdits(t *testing.T) {
41	for _, tc := range difftest.TestCases {
42	edits := diff.Strings(tc.In, tc.Out)
43	got, err := diff.Apply(tc.In, edits)
44	if err != nil {
45	t.Fatalf("Apply failed: %v", err)
46	}
47	if got != tc.Out {
48	t.Fatalf("%s: got %q wanted %q", tc.Name, got, tc.Out)
49	}
50	if len(edits) < len(tc.Edits) { // should find subline edits
51	t.Errorf("got %v, expected %v for %#v", edits, tc.Edits, tc)
52	}
53	}
54	}
55
56	func TestNRandom(t *testing.T) {
57	rand.Seed(1)
58	for i := 0; i < 1000; i++ {
59	a := randstr("abω", 16)
60	b := randstr("abωc", 16)
61	edits := diff.Strings(a, b)
62	got, err := diff.Apply(a, edits)
63	if err != nil {
64	t.Fatalf("Apply failed: %v", err)
65	}
66	if got != b {
67	t.Fatalf("%d: got %q, wanted %q, starting with %q", i, got, b, a)
68	}
69	}
70	}
71
72	// $ go test -fuzz=FuzzRoundTrip ./internal/diff
73	func FuzzRoundTrip(f *testing.F) {
74	f.Fuzz(func(t *testing.T, a, b string) {
75	if !utf8.ValidString(a) \|\| !utf8.ValidString(b) {
76	return // inputs must be text
77	}
78	edits := diff.Strings(a, b)
79	got, err := diff.Apply(a, edits)
80	if err != nil {
81	t.Fatalf("Apply failed: %v", err)
82	}
83	if got != b {
84	t.Fatalf("applying diff(%q, %q) gives %q; edits=%v", a, b, got, edits)
85	}
86	})
87	}
88
89	func TestLineEdits(t *testing.T) {
90	for _, tc := range difftest.TestCases {
91	t.Run(tc.Name, func(t *testing.T) {
92	// if line edits not specified, it is the same as edits
93	edits := tc.LineEdits
94	if edits == nil {
95	edits = tc.Edits
96	}
97	got, err := diff.LineEdits(tc.In, tc.Edits)
98	if err != nil {
99	t.Fatalf("LineEdits: %v", err)
100	}
101	if !reflect.DeepEqual(got, edits) {
102	t.Errorf("LineEdits got %q, want %q", got, edits)
103	}
104	})
105	}
106	}
107
108	func TestToUnified(t *testing.T) {
109	for _, tc := range difftest.TestCases {
110	t.Run(tc.Name, func(t *testing.T) {
111	unified, err := diff.ToUnified(difftest.FileA, difftest.FileB, tc.In, tc.Edits)
112	if err != nil {
113	t.Fatal(err)
114	}
115	if unified != tc.Unified {
116	t.Errorf("Unified(Edits): got diff:\n%v\nexpected:\n%v", unified, tc.Unified)
117	}
118	if tc.LineEdits != nil {
119	unified, err := diff.ToUnified(difftest.FileA, difftest.FileB, tc.In, tc.LineEdits)
120	if err != nil {
121	t.Fatal(err)
122	}
123	if unified != tc.Unified {
124	t.Errorf("Unified(LineEdits): got diff:\n%v\nexpected:\n%v", unified, tc.Unified)
125	}
126	}
127	})
128	}
129	}
130
131	func TestRegressionOld001(t *testing.T) {
132	a := "// Copyright 2019 The Go Authors. All rights reserved.\n// Use of this source code is governed by a BSD-style\n// license that can be found in the LICENSE file.\n\npackage diff_test\n\nimport (\n\t\"fmt\"\n\t\"math/rand\"\n\t\"strings\"\n\t\"testing\"\n\n\t\"golang.org/x/tools/gopls/internal/lsp/diff\"\n\t\"golang.org/x/tools/internal/diff/difftest\"\n\t\"golang.org/x/tools/gopls/internal/span\"\n)\n"
133
134	b := "// Copyright 2019 The Go Authors. All rights reserved.\n// Use of this source code is governed by a BSD-style\n// license that can be found in the LICENSE file.\n\npackage diff_test\n\nimport (\n\t\"fmt\"\n\t\"math/rand\"\n\t\"strings\"\n\t\"testing\"\n\n\t\"github.com/google/safehtml/template\"\n\t\"golang.org/x/tools/gopls/internal/lsp/diff\"\n\t\"golang.org/x/tools/internal/diff/difftest\"\n\t\"golang.org/x/tools/gopls/internal/span\"\n)\n"
135	diffs := diff.Strings(a, b)
136	got, err := diff.Apply(a, diffs)
137	if err != nil {
138	t.Fatalf("Apply failed: %v", err)
139	}
140	if got != b {
141	i := 0
142	for ; i < len(a) && i < len(b) && got[i] == b[i]; i++ {
143	}
144	t.Errorf("oops %vd\n%q\n%q", diffs, got, b)
145	t.Errorf("\n%q\n%q", got[i:], b[i:])
146	}
147	}
148
149	func TestRegressionOld002(t *testing.T) {
150	a := "n\"\n)\n"
151	b := "n\"\n\t\"golang.org/x//nnal/stack\"\n)\n"
152	diffs := diff.Strings(a, b)
153	got, err := diff.Apply(a, diffs)
154	if err != nil {
155	t.Fatalf("Apply failed: %v", err)
156	}
157	if got != b {
158	i := 0
159	for ; i < len(a) && i < len(b) && got[i] == b[i]; i++ {
160	}
161	t.Errorf("oops %vd\n%q\n%q", diffs, got, b)
162	t.Errorf("\n%q\n%q", got[i:], b[i:])
163	}
164	}
165
166	// return a random string of length n made of characters from s
167	func randstr(s string, n int) string {
168	src := []rune(s)
169	x := make([]rune, n)
170	for i := 0; i < n; i++ {
171	x[i] = src[rand.Intn(len(src))]
172	}
173	return string(x)
174	}
175