Function TestDiffLinesParityWithDifflib

diff/lcs_test.go:15–105

TestDiffLinesParityWithDifflib verifies that diffLines produces identical output to difflib.Diff across a variety of inputs, ensuring the linear-space implementation is a drop-in replacement.

(t *testing.T)

// output to difflib.Diff across a variety of inputs, ensuring the
// linear-space implementation is a drop-in replacement.
func TestDiffLinesParityWithDifflib(t *testing.T) {
	cases := []struct {
		name string
		seq1 []string
		seq2 []string
	}{
		{
			name: "both empty",
			seq1: nil,
			seq2: nil,
		},
		{
			name: "first empty",
			seq1: nil,
			seq2: []string{"a", "b"},
		},
		{
			name: "second empty",
			seq1: []string{"a", "b"},
			seq2: nil,
		},
		{
			name: "identical",
			seq1: []string{"a", "b", "c"},
			seq2: []string{"a", "b", "c"},
		},
		{
			name: "completely different",
			seq1: []string{"a", "b", "c"},
			seq2: []string{"x", "y", "z"},
		},
		{
			name: "common prefix only",
			seq1: []string{"a", "b", "c"},
			seq2: []string{"a", "b", "d"},
		},
		{
			name: "common suffix only",
			seq1: []string{"a", "b", "c"},
			seq2: []string{"x", "b", "c"},
		},
		{
			name: "interleaved changes",
			seq1: []string{"line1", "line2", "line3", "line4", "line5"},
			seq2: []string{"line1-changed", "line2", "line3-changed", "line4", "line5-changed"},
		},
		{
			name: "insertions",
			seq1: []string{"a", "c"},
			seq2: []string{"a", "b", "c"},
		},
		{
			name: "deletions",
			seq1: []string{"a", "b", "c"},
			seq2: []string{"a", "c"},
		},
		{
			name: "repeated elements",