this repo has no description
Add tests for LineReaderAt implementation
This adds minimal new coverage, since the apply tests already exercise
this, but it's complicated enough that dedicated tests will be helpful.
+112
+3
gitdiff/io.go
+3
gitdiff/io.go
+109
gitdiff/io_test.go
+109
gitdiff/io_test.go
···
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package gitdiff
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import (
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"bytes"
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"fmt"
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"io"
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"testing"
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)
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func TestLineReaderAt(t *testing.T) {
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tests := map[string]struct {
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InputLines int
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Offset int64
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Count int
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Err bool
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EOF bool
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EOFCount int
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}{
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"readLines": {
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InputLines: 32,
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Offset: 0,
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Count: 4,
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},
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"readLinesOffset": {
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InputLines: 32,
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Offset: 8,
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Count: 4,
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},
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"readLinesLargeOffset": {
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InputLines: 8192,
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Offset: 4096,
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Count: 64,
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},
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"readSingleLine": {
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InputLines: 4,
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Offset: 2,
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Count: 1,
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},
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"readZeroLines": {
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InputLines: 4,
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Offset: 2,
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Count: 0,
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},
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"readThroughEOF": {
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InputLines: 16,
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Offset: 12,
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Count: 8,
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EOF: true,
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EOFCount: 4,
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},
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"offsetAfterEOF": {
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InputLines: 8,
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Offset: 10,
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Count: 2,
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EOF: true,
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EOFCount: 0,
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},
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"offsetNegative": {
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InputLines: 8,
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Offset: -1,
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Count: 2,
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Err: true,
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},
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}
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const lineTemplate = "generated test line %d\n"
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for name, test := range tests {
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t.Run(name, func(t *testing.T) {
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var input bytes.Buffer
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for i := 0; i < test.InputLines; i++ {
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fmt.Fprintf(&input, lineTemplate, i)
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}
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output := make([][]byte, test.Count)
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for i := 0; i < test.Count; i++ {
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output[i] = []byte(fmt.Sprintf(lineTemplate, test.Offset+int64(i)))
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}
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r := &lineReaderAt{r: bytes.NewReader(input.Bytes())}
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lines := make([][]byte, test.Count)
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n, err := r.ReadLinesAt(lines, test.Offset)
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if test.Err {
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if err == nil {
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t.Fatal("expected error reading lines, but got nil")
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}
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return
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}
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if err != nil && (!test.EOF || err != io.EOF) {
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t.Fatalf("unexpected error reading lines: %v", err)
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}
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count := test.Count
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if test.EOF {
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count = test.EOFCount
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}
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if n != count {
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t.Fatalf("incorrect number of lines read: expected %d, actual %d", count, n)
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}
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for i := 0; i < n; i++ {
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if !bytes.Equal(output[i], lines[i]) {
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t.Errorf("incorrect content in line %d:\nexpected: %q\nactual: %q", i, output[i], lines[i])
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}
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}
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})
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}
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}