| 1 | package diff |
| 2 | |
| 3 | import ( |
| 4 | "strings" |
| 5 | "testing" |
| 6 | ) |
| 7 | |
| 8 | func TestBuild_NoChange(t *testing.T) { |
| 9 | c := Build("f.txt", "a\nb\n", "a\nb\n", Modify) |
| 10 | if c.Diff != "" || c.Added != 0 || c.Removed != 0 { |
| 11 | t.Fatalf("identical content should yield empty diff, got %+v", c) |
| 12 | } |
| 13 | } |
| 14 | |
| 15 | func TestBuild_Create(t *testing.T) { |
| 16 | c := Build("new.txt", "", "hello\nworld\n", Create) |
| 17 | if c.Added != 2 || c.Removed != 0 { |
| 18 | t.Fatalf("added/removed = %d/%d, want 2/0", c.Added, c.Removed) |
| 19 | } |
| 20 | if !strings.Contains(c.Diff, "@@ -0,0 +1,2 @@") { |
| 21 | t.Fatalf("create hunk header missing:\n%s", c.Diff) |
| 22 | } |
| 23 | if !strings.Contains(c.Diff, "+hello") || !strings.Contains(c.Diff, "+world") { |
| 24 | t.Fatalf("added lines missing:\n%s", c.Diff) |
| 25 | } |
| 26 | } |
| 27 | |
| 28 | func TestBuild_DeleteAll(t *testing.T) { |
| 29 | c := Build("gone.txt", "x\ny\n", "", Delete) |
| 30 | if c.Added != 0 || c.Removed != 2 { |
| 31 | t.Fatalf("added/removed = %d/%d, want 0/2", c.Added, c.Removed) |
| 32 | } |
| 33 | if !strings.Contains(c.Diff, "@@ -1,2 +0,0 @@") { |
| 34 | t.Fatalf("delete hunk header missing:\n%s", c.Diff) |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | func TestBuild_ModifyMiddle(t *testing.T) { |
| 39 | old := "1\n2\n3\n4\n5\n" |
| 40 | neu := "1\n2\nThree\n4\n5\n" |
| 41 | c := Build("m.txt", old, neu, Modify) |
| 42 | if c.Added != 1 || c.Removed != 1 { |
| 43 | t.Fatalf("added/removed = %d/%d, want 1/1", c.Added, c.Removed) |
| 44 | } |
| 45 | if !strings.Contains(c.Diff, "-3") || !strings.Contains(c.Diff, "+Three") { |
| 46 | t.Fatalf("expected -3/+Three:\n%s", c.Diff) |
| 47 | } |
| 48 | // 3 lines of context each side, but the file only has 2 before and 2 after. |
| 49 | if !strings.Contains(c.Diff, " 1") || !strings.Contains(c.Diff, " 5") { |
| 50 | t.Fatalf("context lines missing:\n%s", c.Diff) |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | func TestBuildWithOptionsPreviewLabelsAndContext(t *testing.T) { |
| 55 | old := "1\n2\n3\n4\n5\n" |
| 56 | neu := "1\n2\nThree\n4\n5\n" |
| 57 | c := BuildWithOptions("m.txt", old, neu, Modify, BuildOptions{ContextLines: 0, Mode: OutputModePreview}) |
| 58 | if c.Mode != string(OutputModePreview) { |
| 59 | t.Fatalf("Mode = %q", c.Mode) |
| 60 | } |
| 61 | if !strings.Contains(c.Diff, "--- before/m.txt") || !strings.Contains(c.Diff, "+++ after/m.txt") { |
| 62 | t.Fatalf("preview labels missing:\n%s", c.Diff) |
| 63 | } |
| 64 | if strings.Contains(c.Diff, " 1") || strings.Contains(c.Diff, " 5") { |
| 65 | t.Fatalf("zero-context diff leaked unchanged context:\n%s", c.Diff) |
| 66 | } |
| 67 | if c.Hunks != 1 { |
| 68 | t.Fatalf("Hunks = %d, want 1:\n%s", c.Hunks, c.Diff) |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | func TestBuildWithOptionsCustomLabels(t *testing.T) { |
| 73 | c := BuildWithOptions("x.txt", "old\n", "new\n", Modify, BuildOptions{ |
| 74 | ContextLines: 1, |
| 75 | OldLabel: "left", |
| 76 | NewLabel: "right", |
| 77 | }) |
| 78 | if !strings.Contains(c.Diff, "--- left") || !strings.Contains(c.Diff, "+++ right") { |
| 79 | t.Fatalf("custom labels missing:\n%s", c.Diff) |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | func TestBuild_Prepend(t *testing.T) { |
| 84 | c := Build("p.txt", "b\nc\n", "a\nb\nc\n", Modify) |
| 85 | if c.Added != 1 || c.Removed != 0 { |
| 86 | t.Fatalf("added/removed = %d/%d, want 1/0", c.Added, c.Removed) |
| 87 | } |
| 88 | if !strings.Contains(c.Diff, "@@ -1,2 +1,3 @@") { |
| 89 | t.Fatalf("prepend header wrong:\n%s", c.Diff) |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | func TestBuild_TwoSeparateHunks(t *testing.T) { |
| 94 | // Two changes far enough apart (>2*context) to form distinct hunks. |
| 95 | old := "a\nb\nc\nd\ne\nf\ng\nh\ni\nj\nk\nl\n" |
| 96 | neu := "a\nB\nc\nd\ne\nf\ng\nh\ni\nj\nK\nl\n" |
| 97 | c := Build("two.txt", old, neu, Modify) |
| 98 | if got := strings.Count(c.Diff, "@@ "); got != 2 { |
| 99 | t.Fatalf("expected 2 hunks, got %d:\n%s", got, c.Diff) |
| 100 | } |
| 101 | if c.Added != 2 || c.Removed != 2 { |
| 102 | t.Fatalf("added/removed = %d/%d, want 2/2", c.Added, c.Removed) |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | func TestBuild_AdjacentChangesMerge(t *testing.T) { |
| 107 | // Changes within 2*context collapse into one hunk. |
| 108 | old := "a\nb\nc\nd\ne\n" |
| 109 | neu := "a\nB\nc\nD\ne\n" |
| 110 | c := Build("adj.txt", old, neu, Modify) |
| 111 | if got := strings.Count(c.Diff, "@@ "); got != 1 { |
| 112 | t.Fatalf("expected 1 merged hunk, got %d:\n%s", got, c.Diff) |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | func TestBuild_NoNewlineAtEOF(t *testing.T) { |
| 117 | c := Build("nonl.txt", "a\nb", "a\nc", Modify) |
| 118 | if !strings.Contains(c.Diff, "\\ No newline at end of file") { |
| 119 | t.Fatalf("expected no-newline marker:\n%s", c.Diff) |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | func TestBuild_Binary(t *testing.T) { |
| 124 | c := Build("bin", "ok\n", "bad\x00data", Modify) |
| 125 | if !c.Binary { |
| 126 | t.Fatal("expected Binary=true") |
| 127 | } |
| 128 | if c.Diff != "" || c.Added != 0 || c.Removed != 0 { |
| 129 | t.Fatalf("binary change should carry no textual diff, got %+v", c) |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | // TestBuild_MinimalEditScript checks the third-party line diff keeps the same |
| 134 | // user-visible contract: a single line inserted into a run of identical lines |
| 135 | // must not be rendered as a block delete+insert. |
| 136 | func TestBuild_MinimalEditScript(t *testing.T) { |
| 137 | old := "x\nx\nx\n" |
| 138 | neu := "x\nx\ny\nx\n" |
| 139 | c := Build("min.txt", old, neu, Modify) |
| 140 | if c.Added != 1 || c.Removed != 0 { |
| 141 | t.Fatalf("added/removed = %d/%d, want 1/0 (minimal):\n%s", c.Added, c.Removed, c.Diff) |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | func TestChangedWindowSize(t *testing.T) { |
| 146 | oldLines, _ := splitLines("a\nb\nc\nd\ne\n") |
| 147 | newLines, _ := splitLines("a\nb\nC\nd\ne\n") |
| 148 | if got := changedWindowSize(oldLines, newLines); got != 2 { |
| 149 | t.Fatalf("single changed line window = %d, want 2", got) |
| 150 | } |
| 151 | oldLines, _ = splitLines("a\nb\nc\nd\ne\n") |
| 152 | newLines, _ = splitLines("a\nB\nc\nD\ne\n") |
| 153 | if got := changedWindowSize(oldLines, newLines); got != 6 { |
| 154 | t.Fatalf("separate changed lines window = %d, want 6", got) |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | func TestExactDiffTooLarge(t *testing.T) { |
| 159 | oldLines := make([]string, maxDiffEdits+1) |
| 160 | newLines := make([]string, maxDiffEdits+1) |
| 161 | for i := range oldLines { |
| 162 | oldLines[i] = "old" |
| 163 | newLines[i] = "new" |
| 164 | } |
| 165 | if !exactDiffTooLarge(oldLines, newLines) { |
| 166 | t.Fatal("large changed window should skip exact diff") |
| 167 | } |
| 168 | } |
| 169 |