diff_test.go

package main

import (
	"errors"
	"strings"
	"testing"

	"github.com/stretchr/testify/require"
)

func TestParseChangeKind(t *testing.T) {
	t.Parallel()

	tests := []struct {
		status string
		want   changeKind
	}{
		{status: "A", want: changeAdded},
		{status: "D", want: changeDeleted},
		{status: "M", want: changeModified},
		{status: "R100", want: changeRenamed},
		{status: "T", want: changeType},
	}
	for _, tt := range tests {
		t.Run(tt.status, func(t *testing.T) {
			t.Parallel()
			kind, err := parseChangeKind(tt.status)
			require.NoError(t, err)
			require.Equal(t, tt.want, kind)
		})
	}
	_, err := parseChangeKind("X")
	require.ErrorContains(t, err, "unsupported diff status")
}

func TestParseDiffHunks(t *testing.T) {
	t.Parallel()

	hunks, err := parseDiffHunks(strings.Join([]string{
		"@@ -10 +12 @@",
		"@@ -0,0 +5,3 @@",
		"@@ -20,4 +30,6 @@",
		"@@ malformed @@",
	}, "\n"))
	require.NoError(t, err)
	require.Equal(t, []diffHunk{
		{Old: lineRange{Start: 10, End: 10}, New: lineRange{Start: 12, End: 12}},
		{Old: lineRange{Start: 1, End: 0}, New: lineRange{Start: 5, End: 7}},
		{Old: lineRange{Start: 20, End: 23}, New: lineRange{Start: 30, End: 35}},
	}, hunks)
}

func TestParseNonNegativeInt(t *testing.T) {
	t.Parallel()

	value, err := parseNonNegativeInt("0")
	require.NoError(t, err)
	require.Zero(t, value)

	value, err = parseNonNegativeInt("42")
	require.NoError(t, err)
	require.Equal(t, 42, value)

	_, err = parseNonNegativeInt("x")
	require.Error(t, err)
}

func TestFileExistsAtRevisionPropagatesLsTreeFailures(t *testing.T) {
	t.Parallel()

	repo := fakeGitRepo{
		revisions: map[string]map[string]string{
			"head": {
				"pkg/sample_test.go": `package sample
`,
			},
		},
		failures: map[string]gitResponse{
			gitKey("ls-tree", "-z", "--name-only", "head", "--", "pkg/sample_test.go"): {
				result: gitResult{},
				err:    errors.New("fatal: ls-tree failed"),
			},
		},
	}
	_, err := fileExistsAtRevision(t.Context(), config{RepoRoot: t.TempDir()}, repo.runner(t), "head", "pkg/sample_test.go")
	require.ErrorContains(t, err, "check whether pkg/sample_test.go exists at head")
}