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authorGravatar Runxi Yu2026-02-20 19:06:13 +0800
committerGravatar Runxi Yu2026-02-20 19:07:14 +0800
commitaa513c069c1418734aea894dc944e27c6a78a3bb (patch)
tree687f0a11bb550fa088fd82a98ceb8979bbc35f69 /difflines/difflines_test.go
parentComment on prior reverts removing the pack writing API (diff)
signatureNo signature
Delete everything, I'm redesigning this.
I'll stop using a flat package and make things much more modular. And also experiment with streaming APIs so large blobs don't OOM us.
Diffstat (limited to 'difflines/difflines_test.go')
-rw-r--r--difflines/difflines_test.go326
1 files changed, 0 insertions, 326 deletions
diff --git a/difflines/difflines_test.go b/difflines/difflines_test.go
deleted file mode 100644
index 783c2d6e..00000000
--- a/difflines/difflines_test.go
+++ /dev/null
@@ -1,326 +0,0 @@
-package difflines
-
-import (
- "bytes"
- "strconv"
- "strings"
- "testing"
-)
-
-func TestDiffLines(t *testing.T) {
- t.Parallel()
-
- tests := []struct {
- name string
- oldInput string
- newInput string
- expected []LinesDiffChunk
- }{
- {
- name: "empty inputs produce no chunks",
- oldInput: "",
- newInput: "",
- expected: []LinesDiffChunk{},
- },
- {
- name: "only additions",
- oldInput: "",
- newInput: "alpha\nbeta\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindAdded, Data: []byte("alpha\nbeta\n")},
- },
- },
- {
- name: "only deletions",
- oldInput: "alpha\nbeta\n",
- newInput: "",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("alpha\nbeta\n")},
- },
- },
- {
- name: "unchanged content is grouped",
- oldInput: "same\nlines\n",
- newInput: "same\nlines\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("same\nlines\n")},
- },
- },
- {
- name: "insertion in the middle",
- oldInput: "a\nb\nc\n",
- newInput: "a\nb\nX\nc\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("a\nb\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("X\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("c\n")},
- },
- },
- {
- name: "replacement without trailing newline",
- oldInput: "first\nsecond",
- newInput: "first\nsecond\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("first\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("second")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("second\n")},
- },
- },
- {
- name: "line replacement",
- oldInput: "a\nb\nc\n",
- newInput: "a\nB\nc\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("a\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("b\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("B\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("c\n")},
- },
- },
- {
- name: "swap adjacent lines",
- oldInput: "A\nB\n",
- newInput: "B\nA\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("A\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("B\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("A\n")},
- },
- },
- {
- name: "indentation change is a full line replacement",
- oldInput: "func main() {\n\treturn\n}\n",
- newInput: "func main() {\n return\n}\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("func main() {\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("\treturn\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte(" return\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("}\n")},
- },
- },
- {
- name: "commenting out lines",
- oldInput: "code\n",
- newInput: "// code\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("code\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("// code\n")},
- },
- },
- {
- name: "reducing repeating lines",
- oldInput: "log\nlog\nlog\n",
- newInput: "log\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("log\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("log\nlog\n")},
- },
- },
- {
- name: "expanding repeating lines",
- oldInput: "tick\n",
- newInput: "tick\ntick\ntick\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("tick\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("tick\ntick\n")},
- },
- },
- {
- name: "interleaved modifications",
- oldInput: "keep\nchange\nkeep\nchange\n",
- newInput: "keep\nfixed\nkeep\nfixed\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("keep\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("change\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("fixed\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("keep\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("change\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("fixed\n")},
- },
- },
- {
- name: "large common header and footer",
- oldInput: "header\nheader\nheader\nOLD\nfooter\nfooter\n",
- newInput: "header\nheader\nheader\nNEW\nfooter\nfooter\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("header\nheader\nheader\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("OLD\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("NEW\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("footer\nfooter\n")},
- },
- },
- {
- name: "completely different content",
- oldInput: "apple\nbanana\n",
- newInput: "cherry\ndate\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("apple\nbanana\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("cherry\ndate\n")},
- },
- },
- {
- name: "unicode and emoji changes",
- oldInput: "Hello 🌍\nYay\n",
- newInput: "Hello 🌎\nYay\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("Hello 🌍\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("Hello 🌎\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("Yay\n")},
- },
- },
- {
- name: "binary data with embedded newlines",
- oldInput: "\x00\x01\n\x02\x03\n",
- newInput: "\x00\x01\n\x02\xFF\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("\x00\x01\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("\x02\x03\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("\x02\xFF\n")},
- },
- },
- {
- name: "adding trailing newline to last line",
- oldInput: "Line 1\nLine 2",
- newInput: "Line 1\nLine 2\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("Line 1\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("Line 2")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("Line 2\n")},
- },
- },
- {
- name: "removing trailing newline",
- oldInput: "A\nB\n",
- newInput: "A\nB",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("A\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("B\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("B")},
- },
- },
- {
- name: "inserting blank lines",
- oldInput: "A\nB\n",
- newInput: "A\n\n\nB\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("A\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("\n\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("B\n")},
- },
- },
- {
- name: "collapsing blank lines",
- oldInput: "A\n\n\n\nB\n",
- newInput: "A\nB\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("A\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("\n\n\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("B\n")},
- },
- },
- {
- name: "case sensitivity check",
- oldInput: "FOO\nbar\n",
- newInput: "foo\nbar\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("FOO\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("foo\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("bar\n")},
- },
- },
- {
- name: "partial line match is full mismatch",
- oldInput: "The quick brown fox\n",
- newInput: "The quick brown fox jumps\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("The quick brown fox\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("The quick brown fox jumps\n")},
- },
- },
- {
- name: "inserting middle content",
- oldInput: "Top\nBottom\n",
- newInput: "Top\nMiddle\nBottom\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("Top\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("Middle\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("Bottom\n")},
- },
- },
- {
- name: "block move simulated",
- oldInput: "BlockA\nBlockB\nBlockC\n",
- newInput: "BlockA\nBlockC\nBlockB\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("BlockA\n")},
- {Kind: LinesDiffChunkKindDeleted, Data: []byte("BlockB\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("BlockC\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("BlockB\n")},
- },
- },
- {
- name: "alternating additions",
- oldInput: "A\nB\nC\n",
- newInput: "A\n1\nB\n2\nC\n",
- expected: []LinesDiffChunk{
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("A\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("1\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("B\n")},
- {Kind: LinesDiffChunkKindAdded, Data: []byte("2\n")},
- {Kind: LinesDiffChunkKindUnchanged, Data: []byte("C\n")},
- },
- },
- }
-
- for _, tt := range tests {
- t.Run(tt.name, func(t *testing.T) {
- t.Parallel()
-
- chunks, err := DiffLines([]byte(tt.oldInput), []byte(tt.newInput))
- if err != nil {
- t.Fatalf("DiffLines returned error: %v", err)
- }
-
- if len(chunks) != len(tt.expected) {
- t.Fatalf("expected %d chunks, got %d: %s", len(tt.expected), len(chunks), formatChunks(chunks))
- }
-
- for i := range tt.expected {
- if chunks[i].Kind != tt.expected[i].Kind {
- t.Fatalf("chunk %d kind mismatch: got %v, want %v; chunks: %s", i, chunks[i].Kind, tt.expected[i].Kind, formatChunks(chunks))
- }
- if !bytes.Equal(chunks[i].Data, tt.expected[i].Data) {
- t.Fatalf("chunk %d data mismatch: got %q, want %q; chunks: %s", i, string(chunks[i].Data), string(tt.expected[i].Data), formatChunks(chunks))
- }
- }
- })
- }
-}
-
-func formatChunks(chunks []LinesDiffChunk) string {
- var b strings.Builder
- b.WriteByte('[')
- for i, chunk := range chunks {
- if i > 0 {
- b.WriteString(", ")
- }
- b.WriteString(chunkKindName(chunk.Kind))
- b.WriteByte(':')
- b.WriteString(strconv.Quote(string(chunk.Data)))
- }
- b.WriteByte(']')
- return b.String()
-}
-
-func chunkKindName(kind LinesDiffChunkKind) string {
- switch kind {
- case LinesDiffChunkKindUnchanged:
- return "U"
- case LinesDiffChunkKindDeleted:
- return "D"
- case LinesDiffChunkKindAdded:
- return "A"
- default:
- return "?"
- }
-}