feat: allow missing formatters (#6)

Closes #3

Reviewed-on: #6
Co-authored-by: Brian McGee <brian@bmcgee.ie>
Co-committed-by: Brian McGee <brian@bmcgee.ie>

internal/cache/cache.go

@@ -61,6 +61,9 @@ func Open(treeRoot string, clean bool) (err error) {
 }
 
 func Close() error {
+	if db == nil {
+		return nil
+	}
 	return db.Close()
 }
 

internal/cli/cli.go

@@ -5,10 +5,11 @@ import "github.com/charmbracelet/log"
 var Cli = Options{}
 
 type Options struct {
-	Verbosity  int    `name:"verbose" short:"v" type:"counter" default:"0" env:"LOG_LEVEL" help:"Set the verbosity of logs e.g. -vv"`
-	ConfigFile string `type:"existingfile" default:"./treefmt.toml"`
-	TreeRoot   string `type:"existingdir" default:"."`
-	ClearCache bool   `short:"c" help:"Reset the evaluation cache. Use in case the cache is not precise enough"`
+	AllowMissingFormatter bool   `default:"false" help:"Do not exit with error if a configured formatter is missing"`
+	ClearCache            bool   `short:"c" help:"Reset the evaluation cache. Use in case the cache is not precise enough"`
+	ConfigFile            string `type:"existingfile" default:"./treefmt.toml"`
+	TreeRoot              string `type:"existingdir" default:"."`
+	Verbosity             int    `name:"verbose" short:"v" type:"counter" default:"0" env:"LOG_LEVEL" help:"Set the verbosity of logs e.g. -vv"`
 
 	Format Format `cmd:"" default:"."`
 }

internal/cli/format.go

@@ -44,7 +44,12 @@ func (f *Format) Run() error {
 
 	// init formatters
 	for name, formatter := range cfg.Formatters {
-		if err = formatter.Init(name); err != nil {
+		err = formatter.Init(name)
+		if err == format.ErrFormatterNotFound && Cli.AllowMissingFormatter {
+			l.Debugf("formatter not found: %v", name)
+			// remove this formatter
+			delete(cfg.Formatters, name)
+		} else if err != nil {
 			return errors.Annotatef(err, "failed to initialise formatter: %v", name)
 		}
 	}
@@ -155,5 +160,7 @@ func (f *Format) Run() error {
 		return cache.ChangeSet(ctx, Cli.TreeRoot, pathsCh)
 	})
 
+	// shutdown.Listen(syscall.SIGINT, syscall.SIGTERM)
+
 	return eg.Wait()
 }

internal/cli/format_test.go

@@ -0,0 +1,68 @@
+package cli
+
+import (
+	"os"
+	"testing"
+
+	"git.numtide.com/numtide/treefmt/internal/format"
+	"github.com/BurntSushi/toml"
+	"github.com/alecthomas/kong"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func writeConfig(t *testing.T, path string, cfg format.Config) {
+	t.Helper()
+	f, err := os.Create(path)
+	if err != nil {
+		t.Fatalf("failed to create a new config file: %v", err)
+	}
+	encoder := toml.NewEncoder(f)
+	if err = encoder.Encode(cfg); err != nil {
+		t.Fatalf("failed to write to config file: %v", err)
+	}
+}
+
+func newKong(t *testing.T, cli interface{}, options ...kong.Option) *kong.Kong {
+	t.Helper()
+	options = append([]kong.Option{
+		kong.Name("test"),
+		kong.Exit(func(int) {
+			t.Helper()
+			t.Fatalf("unexpected exit()")
+		}),
+	}, options...)
+	parser, err := kong.New(cli, options...)
+	assert.NoError(t, err)
+	return parser
+}
+
+func newCli(t *testing.T, args ...string) (*kong.Context, error) {
+	t.Helper()
+	p := newKong(t, &Cli)
+	return p.Parse(args)
+}
+
+func TestAllowMissingFormatter(t *testing.T) {
+	as := require.New(t)
+
+	tempDir := t.TempDir()
+	configPath := tempDir + "/treefmt.toml"
+
+	writeConfig(t, configPath, format.Config{
+		Formatters: map[string]*format.Formatter{
+			"foo-fmt": {
+				Command: "foo-fmt",
+			},
+		},
+	})
+
+	ctx, err := newCli(t, "--config-file", configPath, "--tree-root", tempDir)
+	as.NoError(err)
+	as.Error(ctx.Run(), format.ErrFormatterNotFound)
+
+	ctx, err = newCli(t, "--config-file", configPath, "--tree-root", tempDir, "--allow-missing-formatter")
+	as.NoError(err)
+
+	as.NoError(ctx.Run())
+}

internal/format/config_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestConfig(t *testing.T) {
+func TestReadConfigFile(t *testing.T) {
 	as := require.New(t)
 
 	cfg, err := ReadConfigFile("../../test/treefmt.toml")
@@ -119,4 +119,9 @@ shfmt -i 2 -s -w "$@"
 	as.Equal([]string{"fmt"}, terraform.Options)
 	as.Equal([]string{"*.tf"}, terraform.Includes)
 	as.Nil(terraform.Excludes)
+
+	// missing
+	foo, ok := cfg.Formatters["foo-fmt"]
+	as.True(ok, "foo formatter not found")
+	as.Equal("foo-fmt", foo.Command)
 }

internal/format/format.go

@@ -10,6 +10,10 @@ import (
 	"github.com/juju/errors"
 )
 
+const (
+	ErrFormatterNotFound = errors.ConstError("formatter not found")
+)
+
 type Formatter struct {
 	Name     string
 	Command  string
@@ -32,8 +36,13 @@ type Formatter struct {
 
 func (f *Formatter) Init(name string) error {
 	f.Name = name
-	f.log = log.WithPrefix("format | " + name)
 
+	// test if the formatter is available
+	if err := exec.Command(f.Command, "--help").Run(); err != nil {
+		return ErrFormatterNotFound
+	}
+
+	f.log = log.WithPrefix("format | " + name)
 	f.inbox = make(chan string, 1024)
 
 	f.batchSize = 1024

test/treefmt.toml

@@ -79,4 +79,7 @@ includes = ["*.sh"]
 # see https://github.com/numtide/treefmt/issues/97
 command = "terraform"
 options = ["fmt"]
-includes = ["*.tf"]
+includes = ["*.tf"]
+
+[formatter.foo-fmt]
+command = "foo-fmt"