Add tests for worktree specific resolution

libs/git/worktree.go

@@ -3,6 +3,7 @@ package git
 import (
 	"bufio"
 	"errors"
+	"fmt"
 	"io/fs"
 	"path/filepath"
 	"strings"
@@ -47,7 +48,7 @@ func readGitDir(root vfs.Path) (string, error) {
 	}
 
 	if gitDir == "" {
-		return "", errors.New("gitdir line not found")
+		return "", fmt.Errorf(`expected %q to contain a line with "gitdir: [...]"`, filepath.Join(root.Native(), GitDirectoryName))
 	}
 
 	return gitDir, nil
@@ -62,10 +63,10 @@ func readGitCommonDir(gitDir vfs.Path) (string, error) {
 	}
 
 	if len(lines) == 0 {
-		return "", errors.New("commondir file not found")
+		return "", errors.New("file is empty")
 	}
 
-	return lines[0], nil
+	return strings.TrimSpace(lines[0]), nil
 }
 
 // resolveGitDirs resolves the paths for $GIT_DIR and $GIT_COMMON_DIR.
@@ -107,7 +108,7 @@ func resolveGitDirs(root vfs.Path) (vfs.Path, vfs.Path, error) {
 	// Read value for $GIT_COMMON_DIR.
 	gitCommonDirValue, err := readGitCommonDir(gitDir)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, fmt.Errorf(`expected "commondir" file in worktree git folder at %q: %w`, gitDir.Native(), err)
 	}
 
 	// Resolve $GIT_COMMON_DIR.

libs/git/worktree_test.go

@@ -1 +1,108 @@
 package git
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/databricks/cli/libs/vfs"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func setupWorktree(t *testing.T) string {
+	var err error
+
+	tmpDir := t.TempDir()
+
+	// Checkout path
+	err = os.MkdirAll(filepath.Join(tmpDir, "my_worktree"), os.ModePerm)
+	require.NoError(t, err)
+
+	// Main $GIT_COMMON_DIR
+	err = os.MkdirAll(filepath.Join(tmpDir, ".git"), os.ModePerm)
+	require.NoError(t, err)
+
+	// Worktree $GIT_DIR
+	err = os.MkdirAll(filepath.Join(tmpDir, ".git/worktrees/my_worktree"), os.ModePerm)
+	require.NoError(t, err)
+
+	return tmpDir
+}
+
+func writeGitDir(t *testing.T, dir, content string) {
+	err := os.WriteFile(filepath.Join(dir, "my_worktree/.git"), []byte(content), os.ModePerm)
+	require.NoError(t, err)
+}
+
+func writeGitCommonDir(t *testing.T, dir, content string) {
+	err := os.WriteFile(filepath.Join(dir, ".git/worktrees/my_worktree/commondir"), []byte(content), os.ModePerm)
+	require.NoError(t, err)
+}
+
+func verifyCorrectDirs(t *testing.T, dir string) {
+	gitDir, gitCommonDir, err := resolveGitDirs(vfs.MustNew(filepath.Join(dir, "my_worktree")))
+	require.NoError(t, err)
+	assert.Equal(t, filepath.Join(dir, ".git/worktrees/my_worktree"), gitDir.Native())
+	assert.Equal(t, filepath.Join(dir, ".git"), gitCommonDir.Native())
+}
+
+func TestWorktreeResolveGitDir(t *testing.T) {
+	dir := setupWorktree(t)
+	writeGitCommonDir(t, dir, "../..")
+
+	t.Run("relative", func(t *testing.T) {
+		writeGitDir(t, dir, fmt.Sprintf("gitdir: %s", "../.git/worktrees/my_worktree"))
+		verifyCorrectDirs(t, dir)
+	})
+
+	t.Run("absolute", func(t *testing.T) {
+		writeGitDir(t, dir, fmt.Sprintf("gitdir: %s", filepath.Join(dir, ".git/worktrees/my_worktree")))
+		verifyCorrectDirs(t, dir)
+	})
+
+	t.Run("additional spaces", func(t *testing.T) {
+		writeGitDir(t, dir, fmt.Sprintf("gitdir:    %s     \n\n\n", "../.git/worktrees/my_worktree"))
+		verifyCorrectDirs(t, dir)
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		writeGitDir(t, dir, "")
+
+		_, _, err := resolveGitDirs(vfs.MustNew(filepath.Join(dir, "my_worktree")))
+		assert.ErrorContains(t, err, ` to contain a line with "gitdir: [...]"`)
+	})
+}
+
+func TestWorktreeResolveCommonDir(t *testing.T) {
+	dir := setupWorktree(t)
+	writeGitDir(t, dir, fmt.Sprintf("gitdir: %s", "../.git/worktrees/my_worktree"))
+
+	t.Run("relative", func(t *testing.T) {
+		writeGitCommonDir(t, dir, "../..")
+		verifyCorrectDirs(t, dir)
+	})
+
+	t.Run("absolute", func(t *testing.T) {
+		writeGitCommonDir(t, dir, filepath.Join(dir, ".git"))
+		verifyCorrectDirs(t, dir)
+	})
+
+	t.Run("additional spaces", func(t *testing.T) {
+		writeGitCommonDir(t, dir, "    ../..    \n\n\n")
+		verifyCorrectDirs(t, dir)
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		writeGitCommonDir(t, dir, "")
+
+		_, _, err := resolveGitDirs(vfs.MustNew(filepath.Join(dir, "my_worktree")))
+		assert.ErrorContains(t, err, `expected "commondir" file in worktree git folder at `)
+	})
+
+	t.Run("missing", func(t *testing.T) {
+		_, _, err := resolveGitDirs(vfs.MustNew(filepath.Join(dir, "my_worktree")))
+		assert.ErrorContains(t, err, `expected "commondir" file in worktree git folder at `)
+	})
+}