fix: fmt command with symlinks

pkg/commands/fmt.go

@@ -113,14 +113,11 @@ func (c *fmtCommand) preRunE(_ *cobra.Command, _ []string) error {
 }
 
 func (c *fmtCommand) execute(_ *cobra.Command, args []string) error {
-	paths, err := cleanArgs(args)
-	if err != nil {
-		return fmt.Errorf("failed to clean arguments: %w", err)
-	}
+	paths := cleanArgs(args)
 
 	c.log.Infof("Formatting Go files...")
 
-	err = c.runner.Run(paths)
+	err := c.runner.Run(paths)
 	if err != nil {
 		return fmt.Errorf("failed to process files: %w", err)
 	}
@@ -134,25 +131,15 @@ func (c *fmtCommand) persistentPostRun(_ *cobra.Command, _ []string) {
 	}
 }
 
-func cleanArgs(args []string) ([]string, error) {
+func cleanArgs(args []string) []string {
 	if len(args) == 0 {
-		abs, err := filepath.Abs(".")
-		if err != nil {
-			return nil, err
-		}
-
-		return []string{abs}, nil
+		return []string{"."}
 	}
 
 	var expanded []string
 	for _, arg := range args {
-		abs, err := filepath.Abs(strings.ReplaceAll(arg, "...", ""))
-		if err != nil {
-			return nil, err
-		}
-
-		expanded = append(expanded, abs)
+		expanded = append(expanded, filepath.Clean(strings.ReplaceAll(arg, "...", "")))
 	}
 
-	return expanded, nil
+	return expanded
 }

pkg/goformat/runner.go

@@ -223,8 +223,14 @@ func NewRunnerOptions(cfg *config.Config, diff, diffColored, stdin bool) (Runner
 		return RunnerOptions{}, fmt.Errorf("get base path: %w", err)
 	}
 
+	// Required to be consistent with `RunnerOptions.MatchAnyPattern`.
+	absBasePath, err := filepath.Abs(basePath)
+	if err != nil {
+		return RunnerOptions{}, err
+	}
+
 	opts := RunnerOptions{
-		basePath:            basePath,
+		basePath:            absBasePath,
 		generated:           cfg.Formatters.Exclusions.Generated,
 		diff:                diff || diffColored,
 		colors:              diffColored,
@@ -251,7 +257,12 @@ func (o RunnerOptions) MatchAnyPattern(path string) (bool, error) {
 		return false, nil
 	}
 
-	rel, err := filepath.Rel(o.basePath, path)
+	abs, err := filepath.Abs(path)
+	if err != nil {
+		return false, err
+	}
+
+	rel, err := filepath.Rel(o.basePath, abs)
 	if err != nil {
 		return false, err
 	}
@@ -272,7 +283,7 @@ func skipDir(name string) bool {
 		return true
 
 	default:
-		return strings.HasPrefix(name, ".")
+		return strings.HasPrefix(name, ".") && name != "."
 	}
 }
 

pkg/goformat/runner_test.go

@@ -0,0 +1,140 @@
+package goformat
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/golangci/golangci-lint/v2/pkg/config"
+)
+
+func TestRunnerOptions_MatchAnyPattern(t *testing.T) {
+	testCases := []struct {
+		desc     string
+		cfg      *config.Config
+		filename string
+
+		assertMatch   assert.BoolAssertionFunc
+		expectedCount int
+	}{
+		{
+			desc: "match",
+			cfg: &config.Config{
+				Formatters: config.Formatters{
+					Exclusions: config.FormatterExclusions{
+						Paths: []string{`generated\.go`},
+					},
+				},
+			},
+			filename:      "generated.go",
+			assertMatch:   assert.True,
+			expectedCount: 1,
+		},
+		{
+			desc: "no match",
+			cfg: &config.Config{
+				Formatters: config.Formatters{
+					Exclusions: config.FormatterExclusions{
+						Paths: []string{`excluded\.go`},
+					},
+				},
+			},
+			filename:      "test.go",
+			assertMatch:   assert.False,
+			expectedCount: 0,
+		},
+		{
+			desc:        "no patterns",
+			cfg:         &config.Config{},
+			filename:    "test.go",
+			assertMatch: assert.False,
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			tmpDir := t.TempDir()
+
+			testFile := filepath.Join(tmpDir, test.filename)
+
+			err := os.WriteFile(testFile, []byte("package main"), 0o600)
+			require.NoError(t, err)
+
+			test.cfg.SetConfigDir(tmpDir)
+
+			opts, err := NewRunnerOptions(test.cfg, false, false, false)
+			require.NoError(t, err)
+
+			match, err := opts.MatchAnyPattern(testFile)
+			require.NoError(t, err)
+
+			test.assertMatch(t, match)
+
+			require.Len(t, opts.patterns, len(test.cfg.Formatters.Exclusions.Paths))
+
+			if len(opts.patterns) == 0 {
+				assert.Empty(t, opts.excludedPathCounter)
+			} else {
+				assert.Equal(t, test.expectedCount, opts.excludedPathCounter[opts.patterns[0]])
+			}
+		})
+	}
+}
+
+// File structure:
+//
+//	tmp
+//	├── project (`realDir`)
+//	│   ├── .golangci.yml
+//	│   └── test.go
+//	└── somewhere
+//	    └── symlink (to "project")
+func TestRunnerOptions_MatchAnyPattern_withSymlinks(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	testFile := filepath.Join(tmpDir, "project", "test.go")
+
+	realDir := filepath.Dir(testFile)
+
+	err := os.MkdirAll(realDir, 0o755)
+	require.NoError(t, err)
+
+	err = os.WriteFile(testFile, []byte("package main"), 0o600)
+	require.NoError(t, err)
+
+	symlink := filepath.Join(tmpDir, "somewhere", "symlink")
+
+	err = os.MkdirAll(filepath.Dir(symlink), 0o755)
+	require.NoError(t, err)
+
+	err = os.Symlink(realDir, symlink)
+	require.NoError(t, err)
+
+	cfg := &config.Config{
+		Formatters: config.Formatters{
+			Exclusions: config.FormatterExclusions{
+				Paths: []string{`^[^/\\]+\.go$`},
+			},
+		},
+	}
+
+	cfg.SetConfigDir(symlink)
+
+	opts, err := NewRunnerOptions(cfg, false, false, false)
+	require.NoError(t, err)
+
+	match, err := opts.MatchAnyPattern(filepath.Join(symlink, "test.go"))
+	require.NoError(t, err)
+
+	assert.True(t, match)
+
+	require.NotEmpty(t, opts.patterns)
+	require.Len(t, opts.patterns, len(cfg.Formatters.Exclusions.Paths))
+
+	assert.Equal(t, 1, opts.excludedPathCounter[opts.patterns[0]])
+}