once/closer: refactor api (#338)

Author: matthewmueller

internal/once/closer.go

@@ -1,17 +1,22 @@
 package once
 
-import "github.com/livebud/bud/internal/errs"
+import (
+	"github.com/livebud/bud/internal/errs"
+)
 
 type Closer struct {
-	Closes []func() error
+	closes []func() error
 	once   Error
 }
 
-func (c *Closer) Close(reasons ...error) error {
+func (c *Closer) Add(fn func() error) {
+	c.closes = append(c.closes, fn)
+}
+
+func (c *Closer) Close() (err error) {
 	return c.once.Do(func() error {
-		err := errs.Join(reasons...)
-		for i := len(c.Closes) - 1; i >= 0; i-- {
-			err = errs.Join(err, c.Closes[i]())
+		for i := len(c.closes) - 1; i >= 0; i-- {
+			err = errs.Join(err, c.closes[i]())
 		}
 		return err
 	})

internal/once/closer_test.go

@@ -13,33 +13,21 @@ func TestCloserOk(t *testing.T) {
 	var closer once.Closer
 	a := func() error { return nil }
 	b := func() error { return nil }
-	closer.Closes = append(closer.Closes, a)
-	closer.Closes = append(closer.Closes, b)
+	closer.Add(a)
+	closer.Add(b)
 	err := closer.Close()
 	is.NoErr(err)
 }
 
-func TestCloserReason(t *testing.T) {
-	is := is.New(t)
-	e := errors.New("error")
-	var closer once.Closer
-	a := func() error { return nil }
-	b := func() error { return nil }
-	closer.Closes = append(closer.Closes, a)
-	closer.Closes = append(closer.Closes, b)
-	err := closer.Close(e)
-	is.True(errors.Is(err, e))
-}
-
 func TestCloserErrors(t *testing.T) {
 	is := is.New(t)
 	e1 := errors.New("error 1")
 	e2 := errors.New("error 2")
 	var closer once.Closer
 	a := func() error { return e1 }
 	b := func() error { return e2 }
-	closer.Closes = append(closer.Closes, a)
-	closer.Closes = append(closer.Closes, b)
+	closer.Add(a)
+	closer.Add(b)
 	err := closer.Close()
 	is.True(err != nil)
 	is.Equal(err.Error(), "error 2. error 1")

package/budfs/budfs.go

@@ -438,7 +438,7 @@ func (f *fileSystem) Context() context.Context {
 // Defer a function until close is called. May be called multiple times if
 // generators are triggered multiple times.
 func (f *fileSystem) Defer(fn func() error) {
-	f.fsys.closer.Closes = append(f.fsys.closer.Closes, fn)
+	f.fsys.closer.Add(fn)
 }
 
 // Glob implements fs.GlobFS

package/remotefs/command.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"io/fs"
 
+	"github.com/livebud/bud/internal/errs"
 	"github.com/livebud/bud/internal/exe"
 	"github.com/livebud/bud/internal/extrafile"
 	"github.com/livebud/bud/internal/once"
@@ -24,28 +25,31 @@ func (c *Command) Start(ctx context.Context, name string, args ...string) (*Proc
 	if err != nil {
 		return nil, err
 	}
-	closer.Closes = append(closer.Closes, ln.Close)
+	closer.Add(ln.Close)
 	// Turn the listener into a file to be passed to the subprocess
 	file, err := ln.File()
 	if err != nil {
-		return nil, closer.Close(err)
+		err = errs.Join(err, closer.Close())
+		return nil, err
 	}
-	closer.Closes = append(closer.Closes, file.Close)
+	closer.Add(file.Close)
 	// Inject the file listener into the subprocess
 	extrafile.Inject(&c.ExtraFiles, &c.Env, defaultPrefix, file)
 	// Start the subprocess
 	process, err := (*exe.Command)(c).Start(ctx, name, args...)
 	if err != nil {
-		return nil, closer.Close(err)
+		err = errs.Join(err, closer.Close())
+		return nil, err
 	}
-	closer.Closes = append(closer.Closes, process.Close)
+	closer.Add(process.Close)
 	// Dial the subprocess and return a client
 	addr := ln.Addr().String()
 	client, err := Dial(ctx, addr)
 	if err != nil {
-		return nil, closer.Close(err)
+		err = errs.Join(err, closer.Close())
+		return nil, err
 	}
-	closer.Closes = append(closer.Closes, client.Close)
+	closer.Add(client.Close)
 	// Return the process
 	return &Process{client, &closer, process, addr}, nil
 }