feat: add --exclude / -x option to hide files from message generation

cmd/git-ai-commit/main.go

@@ -23,6 +23,7 @@ type options struct {
 	amend        bool
 	addAll       bool
 	includeFiles []string
+	excludeFiles []string
 	debugPrompt  bool
 	debugCommand bool
 }
@@ -51,6 +52,7 @@ func main() {
 		opts.amend,
 		opts.addAll,
 		opts.includeFiles,
+		opts.excludeFiles,
 		opts.debugPrompt,
 		opts.debugCommand,
 	); err != nil {
@@ -76,7 +78,7 @@ func parseArgs(args []string) (options, error) {
 				return opts, errHelp
 			case "version":
 				return opts, errVersion
-			case "context", "context-file", "prompt", "prompt-file", "engine", "include":
+			case "context", "context-file", "prompt", "prompt-file", "engine", "include", "exclude":
 				if !hasValue {
 					if i+1 >= len(args) {
 						return opts, fmt.Errorf("missing value for --%s", name)
@@ -132,6 +134,11 @@ func applyLongOption(opts *options, name, value string) error {
 			return fmt.Errorf("missing value for --include")
 		}
 		opts.includeFiles = append(opts.includeFiles, value)
+	case "exclude":
+		if value == "" {
+			return fmt.Errorf("missing value for --exclude")
+		}
+		opts.excludeFiles = append(opts.excludeFiles, value)
 	default:
 		return fmt.Errorf("unknown option --%s", name)
 	}
@@ -167,6 +174,26 @@ func parseShortOptions(opts *options, arg string, args []string, index *int) err
 				return fmt.Errorf("missing value for -i")
 			}
 			opts.includeFiles = append(opts.includeFiles, value)
+		case 'x':
+			value := ""
+			if i+1 < len(cluster) {
+				if cluster[i+1] == '=' {
+					value = cluster[i+2:]
+				} else {
+					value = cluster[i+1:]
+				}
+				i = len(cluster)
+			} else {
+				if *index+1 >= len(args) {
+					return fmt.Errorf("missing value for -x")
+				}
+				*index++
+				value = args[*index]
+			}
+			if value == "" {
+				return fmt.Errorf("missing value for -x")
+			}
+			opts.excludeFiles = append(opts.excludeFiles, value)
 		case 'h':
 			return errHelp
 		default:
@@ -189,6 +216,7 @@ func printUsage(out *os.File) {
 	fmt.Fprintln(out, "  --amend                   Amend the previous commit")
 	fmt.Fprintln(out, "  -a, --all                 Stage modified and deleted files before generating the message")
 	fmt.Fprintln(out, "  -i, --include VALUE       Stage specific files before generating the message")
+	fmt.Fprintln(out, "  -x, --exclude VALUE       Hide specific files from the diff for message generation")
 	fmt.Fprintln(out, "  --debug-prompt            Print the prompt before executing the engine")
 	fmt.Fprintln(out, "  --debug-command           Print the engine command before execution")
 	fmt.Fprintln(out, "  -h, --help                Show help")

cmd/git-ai-commit/main_test.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestParseArgs_ExcludeLong(t *testing.T) {
+	opts, err := parseArgs([]string{"--exclude", "go.sum"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(opts.excludeFiles) != 1 || opts.excludeFiles[0] != "go.sum" {
+		t.Errorf("expected excludeFiles=[go.sum], got %v", opts.excludeFiles)
+	}
+}
+
+func TestParseArgs_ExcludeLongEquals(t *testing.T) {
+	opts, err := parseArgs([]string{"--exclude=go.sum"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(opts.excludeFiles) != 1 || opts.excludeFiles[0] != "go.sum" {
+		t.Errorf("expected excludeFiles=[go.sum], got %v", opts.excludeFiles)
+	}
+}
+
+func TestParseArgs_ExcludeShort(t *testing.T) {
+	opts, err := parseArgs([]string{"-x", "go.sum"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(opts.excludeFiles) != 1 || opts.excludeFiles[0] != "go.sum" {
+		t.Errorf("expected excludeFiles=[go.sum], got %v", opts.excludeFiles)
+	}
+}
+
+func TestParseArgs_ExcludeMultiple(t *testing.T) {
+	opts, err := parseArgs([]string{"--exclude", "go.sum", "-x", "vendor/deps.go"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(opts.excludeFiles) != 2 {
+		t.Fatalf("expected 2 excludeFiles, got %v", opts.excludeFiles)
+	}
+	if opts.excludeFiles[0] != "go.sum" || opts.excludeFiles[1] != "vendor/deps.go" {
+		t.Errorf("expected [go.sum, vendor/deps.go], got %v", opts.excludeFiles)
+	}
+}
+
+func TestParseArgs_ExcludeMissingValue(t *testing.T) {
+	_, err := parseArgs([]string{"--exclude"})
+	if err == nil {
+		t.Fatal("expected error for missing value")
+	}
+}
+
+func TestParseArgs_ExcludeShortMissingValue(t *testing.T) {
+	_, err := parseArgs([]string{"-x"})
+	if err == nil {
+		t.Fatal("expected error for missing value")
+	}
+}
+
+func TestParseArgs_ExcludeShortCluster(t *testing.T) {
+	opts, err := parseArgs([]string{"-ax", "go.sum"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !opts.addAll {
+		t.Error("expected addAll to be true")
+	}
+	if len(opts.excludeFiles) != 1 || opts.excludeFiles[0] != "go.sum" {
+		t.Errorf("expected excludeFiles=[go.sum], got %v", opts.excludeFiles)
+	}
+}

internal/app/app.go

@@ -11,7 +11,7 @@ import (
 	"git-ai-commit/internal/prompt"
 )
 
-func Run(context, contextFile, promptName, promptFile, engineName string, amend, addAll bool, includeFiles []string, debugPrompt, debugCommand bool) (err error) {
+func Run(context, contextFile, promptName, promptFile, engineName string, amend, addAll bool, includeFiles, excludeFiles []string, debugPrompt, debugCommand bool) (err error) {
 	cfg, err := config.Load()
 	if err != nil {
 		return err
@@ -45,7 +45,7 @@ func Run(context, contextFile, promptName, promptFile, engineName string, amend,
 		}
 	}
 
-	diff, err := commitDiff(amend, cfg)
+	diff, err := commitDiff(amend, cfg, excludeFiles)
 	if err != nil {
 		return err
 	}
@@ -141,7 +141,7 @@ func sanitizeMessage(message string) string {
 	return clean
 }
 
-func commitDiff(amend bool, cfg config.Config) (string, error) {
+func commitDiff(amend bool, cfg config.Config, excludeFiles []string) (string, error) {
 	var diff string
 	var err error
 	if amend {
@@ -169,6 +169,7 @@ func commitDiff(amend bool, cfg config.Config) (string, error) {
 	opts := git.Options{
 		MaxFileLines:    maxLines,
 		ExcludePatterns: patterns,
+		ExcludeFiles:    excludeFiles,
 	}
 	result := git.Filter(diff, opts)
 

internal/git/filter.go

@@ -29,6 +29,7 @@ func DefaultExcludePatterns() []string {
 type Options struct {
 	MaxFileLines    int      // Maximum lines per file (0 = no limit)
 	ExcludePatterns []string // Glob patterns for files to exclude
+	ExcludeFiles    []string // Exact file paths to exclude
 }
 
 // Result holds the filtering outcome.
@@ -63,6 +64,12 @@ func Filter(diff string, opts Options) Result {
 	for _, fileName := range fileNames {
 		content := files[fileName]
 
+		// Check exact file exclusions
+		if containsFile(fileName, opts.ExcludeFiles) {
+			result.ExcludedFiles = append(result.ExcludedFiles, fileName)
+			continue
+		}
+
 		// Check exclusion patterns
 		if matchesAnyPattern(fileName, opts.ExcludePatterns) {
 			result.ExcludedFiles = append(result.ExcludedFiles, fileName)
@@ -212,6 +219,16 @@ func truncateFileDiff(content string, maxLines int, fileName string) (bool, stri
 	return true, result.String()
 }
 
+// containsFile checks if filePath is in the given list of exact paths.
+func containsFile(filePath string, files []string) bool {
+	for _, f := range files {
+		if f == filePath {
+			return true
+		}
+	}
+	return false
+}
+
 // matchesAnyPattern checks if the file path matches any of the glob patterns.
 func matchesAnyPattern(filePath string, patterns []string) bool {
 	for _, pattern := range patterns {

internal/git/filter_test.go

@@ -311,6 +311,153 @@ func TestMatchPattern_DoubleStarGlob(t *testing.T) {
 	}
 }
 
+func TestFilter_ExcludeFilesByExactPath(t *testing.T) {
+	diff := `diff --git a/go.sum b/go.sum
+index abc123..def456 100644
+--- a/go.sum
++++ b/go.sum
+@@ -1,3 +1,4 @@
++module v1.0.0 h1:abc=
+diff --git a/main.go b/main.go
+index abc123..def456 100644
+--- a/main.go
++++ b/main.go
+@@ -1,3 +1,4 @@
++code
+`
+	result := Filter(diff, Options{
+		ExcludeFiles: []string{"go.sum"},
+	})
+
+	if len(result.ExcludedFiles) != 1 || result.ExcludedFiles[0] != "go.sum" {
+		t.Errorf("expected excluded file 'go.sum', got %v", result.ExcludedFiles)
+	}
+	if strings.Contains(result.Diff, "go.sum") {
+		t.Error("expected go.sum to be excluded from diff")
+	}
+	if !strings.Contains(result.Diff, "main.go") {
+		t.Error("expected main.go to be in diff")
+	}
+}
+
+func TestFilter_ExcludeFilesMultiple(t *testing.T) {
+	diff := `diff --git a/go.sum b/go.sum
+index abc123..def456 100644
+--- a/go.sum
++++ b/go.sum
+@@ -1,3 +1,4 @@
++sum content
+diff --git a/main.go b/main.go
+index abc123..def456 100644
+--- a/main.go
++++ b/main.go
+@@ -1,3 +1,4 @@
++code
+diff --git a/vendor/deps.go b/vendor/deps.go
+index abc123..def456 100644
+--- a/vendor/deps.go
++++ b/vendor/deps.go
+@@ -1,3 +1,4 @@
++deps
+`
+	result := Filter(diff, Options{
+		ExcludeFiles: []string{"go.sum", "vendor/deps.go"},
+	})
+
+	if len(result.ExcludedFiles) != 2 {
+		t.Errorf("expected 2 excluded files, got %v", result.ExcludedFiles)
+	}
+	if strings.Contains(result.Diff, "go.sum") {
+		t.Error("expected go.sum to be excluded from diff")
+	}
+	if strings.Contains(result.Diff, "vendor/deps.go") {
+		t.Error("expected vendor/deps.go to be excluded from diff")
+	}
+	if !strings.Contains(result.Diff, "main.go") {
+		t.Error("expected main.go to be in diff")
+	}
+}
+
+func TestFilter_ExcludeFilesNoMatch(t *testing.T) {
+	diff := `diff --git a/main.go b/main.go
+index abc123..def456 100644
+--- a/main.go
++++ b/main.go
+@@ -1,3 +1,4 @@
++code
+`
+	result := Filter(diff, Options{
+		ExcludeFiles: []string{"nonexistent.go"},
+	})
+
+	if len(result.ExcludedFiles) != 0 {
+		t.Errorf("expected no excluded files, got %v", result.ExcludedFiles)
+	}
+	if !strings.Contains(result.Diff, "main.go") {
+		t.Error("expected main.go to be in diff")
+	}
+}
+
+func TestFilter_ExcludeFilesCombinedWithPatterns(t *testing.T) {
+	diff := `diff --git a/go.sum b/go.sum
+index abc123..def456 100644
+--- a/go.sum
++++ b/go.sum
+@@ -1,3 +1,4 @@
++sum content
+diff --git a/package-lock.json b/package-lock.json
+index abc123..def456 100644
+--- a/package-lock.json
++++ b/package-lock.json
+@@ -1,3 +1,4 @@
++lock content
+diff --git a/main.go b/main.go
+index abc123..def456 100644
+--- a/main.go
++++ b/main.go
+@@ -1,3 +1,4 @@
++code
+`
+	result := Filter(diff, Options{
+		ExcludeFiles:    []string{"go.sum"},
+		ExcludePatterns: []string{"**/*-lock.json"},
+	})
+
+	if len(result.ExcludedFiles) != 2 {
+		t.Errorf("expected 2 excluded files, got %v", result.ExcludedFiles)
+	}
+	if strings.Contains(result.Diff, "go.sum") {
+		t.Error("expected go.sum to be excluded from diff")
+	}
+	if strings.Contains(result.Diff, "package-lock.json") {
+		t.Error("expected package-lock.json to be excluded from diff")
+	}
+	if !strings.Contains(result.Diff, "main.go") {
+		t.Error("expected main.go to be in diff")
+	}
+}
+
+func TestContainsFile(t *testing.T) {
+	tests := []struct {
+		filePath string
+		files    []string
+		want     bool
+	}{
+		{"go.sum", []string{"go.sum"}, true},
+		{"vendor/deps.go", []string{"vendor/deps.go"}, true},
+		{"main.go", []string{"go.sum", "vendor/deps.go"}, false},
+		{"go.sum", []string{}, false},
+		{"go.sum", nil, false},
+	}
+
+	for _, tt := range tests {
+		got := containsFile(tt.filePath, tt.files)
+		if got != tt.want {
+			t.Errorf("containsFile(%q, %v) = %v, want %v", tt.filePath, tt.files, got, tt.want)
+		}
+	}
+}
+
 func TestExtractFilePath(t *testing.T) {
 	tests := []struct {
 		line string