Replace sync.Once with sync.OnceFunc/OnceValue/OnceValues

.golangci.yaml

@@ -66,6 +66,8 @@ linters:
           msg: Use errors.Is(err, fs.ErrExist) instead.
         - pattern: 'os\.IsPermission'
           msg: Use errors.Is(err, fs.ErrPermission) instead.
+        - pattern: 'sync\.Once\b($|[^FV])'
+          msg: Use sync.OnceFunc, sync.OnceValue, or sync.OnceValues instead.
       analyze-types: true
     copyloopvar:
       check-alias: true

bundle/bundle.go

@@ -8,7 +8,6 @@ package bundle
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -121,11 +120,8 @@ type Bundle struct {
 	// in the WSFS location containing the bundle state.
 	Metadata metadata.Metadata
 
-	// Store a pointer to the workspace client.
-	// It can be initialized on demand after loading the configuration.
-	clientOnce sync.Once
-	client     *databricks.WorkspaceClient
-	clientErr  error
+	// Returns the workspace client, initializing it on first call.
+	getClient func() (*databricks.WorkspaceClient, error)
 
 	// Files that are synced to the workspace.file_path
 	Files []fileset.File
@@ -225,16 +221,21 @@ func TryLoad(ctx context.Context) *Bundle {
 	return b
 }
 
-func (b *Bundle) WorkspaceClientE() (*databricks.WorkspaceClient, error) {
-	b.clientOnce.Do(func() {
-		var err error
-		b.client, err = b.Config.Workspace.Client()
+func (b *Bundle) initClientOnce() {
+	b.getClient = sync.OnceValues(func() (*databricks.WorkspaceClient, error) {
+		w, err := b.Config.Workspace.Client()
 		if err != nil {
-			b.clientErr = fmt.Errorf("cannot resolve bundle auth configuration: %w", err)
+			return nil, fmt.Errorf("cannot resolve bundle auth configuration: %w", err)
 		}
+		return w, nil
 	})
+}
 
-	return b.client, b.clientErr
+func (b *Bundle) WorkspaceClientE() (*databricks.WorkspaceClient, error) {
+	if b.getClient == nil {
+		b.initClientOnce()
+	}
+	return b.getClient()
 }
 
 func (b *Bundle) WorkspaceClient() *databricks.WorkspaceClient {
@@ -249,16 +250,15 @@ func (b *Bundle) WorkspaceClient() *databricks.WorkspaceClient {
 // SetWorkpaceClient sets the workspace client for this bundle.
 // This is used to inject a mock client for testing.
 func (b *Bundle) SetWorkpaceClient(w *databricks.WorkspaceClient) {
-	b.clientOnce.Do(func() {})
-	b.client = w
+	b.getClient = func() (*databricks.WorkspaceClient, error) {
+		return w, nil
+	}
 }
 
 // ClearWorkspaceClient resets the workspace client cache, allowing
 // WorkspaceClientE() to attempt client creation again on the next call.
 func (b *Bundle) ClearWorkspaceClient() {
-	b.clientOnce = sync.Once{}
-	b.client = nil
-	b.clientErr = nil
+	b.initClientOnce()
 }
 
 // LocalStateDir returns directory to use for temporary files for this bundle without creating
@@ -347,12 +347,12 @@ func (b *Bundle) GetSyncIncludePatterns(ctx context.Context) ([]string, error) {
 // This map can be used to configure authentication for tools that
 // we call into from this bundle context.
 func (b *Bundle) AuthEnv() (map[string]string, error) {
-	if b.client == nil {
-		return nil, errors.New("workspace client not initialized yet")
+	w, err := b.WorkspaceClientE()
+	if err != nil {
+		return nil, err
 	}
 
-	cfg := b.client.Config
-	return auth.Env(cfg), nil
+	return auth.Env(w.Config), nil
 }
 
 // StateFilenameDirect returns (relative remote path, relative local path) for direct engine resource state

bundle/direct/dresources/config.go

@@ -75,48 +75,36 @@ var resourcesYAML []byte
 //go:embed resources.generated.yml
 var resourcesGeneratedYAML []byte
 
-var (
-	configOnce          sync.Once
-	globalConfig        *Config
-	generatedConfigOnce sync.Once
-	generatedConfig     *Config
-	empty               = ResourceLifecycleConfig{
-		IgnoreRemoteChanges: nil,
-		IgnoreLocalChanges:  nil,
-		RecreateOnChanges:   nil,
-		UpdateIDOnChanges:   nil,
-		BackendDefaults:     nil,
-	}
-)
+var empty = ResourceLifecycleConfig{
+	IgnoreRemoteChanges: nil,
+	IgnoreLocalChanges:  nil,
+	RecreateOnChanges:   nil,
+	UpdateIDOnChanges:   nil,
+	BackendDefaults:     nil,
+}
 
-// MustLoadConfig loads and parses the embedded resources.yml configuration.
-// The config is loaded once and cached for subsequent calls.
-// Panics if the embedded YAML is invalid.
-func MustLoadConfig() *Config {
-	configOnce.Do(func() {
-		globalConfig = &Config{
-			Resources: nil,
-		}
-		if err := yaml.Unmarshal(resourcesYAML, globalConfig); err != nil {
+func mustParseConfig(data []byte) func() *Config {
+	return sync.OnceValue(func() *Config {
+		c := &Config{Resources: nil}
+		if err := yaml.Unmarshal(data, c); err != nil {
 			panic(err)
 		}
+		return c
 	})
-	return globalConfig
 }
 
-// MustLoadGeneratedConfig loads and parses the embedded resources.generated.yml configuration.
-// The config is loaded once and cached for subsequent calls.
-// Panics if the embedded YAML is invalid.
+var loadConfig = mustParseConfig(resourcesYAML)
+
+var loadGeneratedConfig = mustParseConfig(resourcesGeneratedYAML)
+
+// MustLoadConfig returns the parsed resources.yml configuration.
+func MustLoadConfig() *Config {
+	return loadConfig()
+}
+
+// MustLoadGeneratedConfig returns the parsed resources.generated.yml configuration.
 func MustLoadGeneratedConfig() *Config {
-	generatedConfigOnce.Do(func() {
-		generatedConfig = &Config{
-			Resources: nil,
-		}
-		if err := yaml.Unmarshal(resourcesGeneratedYAML, generatedConfig); err != nil {
-			panic(err)
-		}
-	})
-	return generatedConfig
+	return loadGeneratedConfig()
 }
 
 // GetResourceConfig returns the lifecycle config for a given resource type.

internal/build/info.go

@@ -42,10 +42,6 @@ func (i Info) GetSanitizedVersion() string {
 	return version
 }
 
-var info Info
-
-var once sync.Once
-
 const DefaultSemver = "0.0.0-dev"
 
 // getDefaultBuildVersion uses build information stored by Go itself
@@ -73,7 +69,7 @@ func getDefaultBuildVersion() string {
 	return out
 }
 
-func initialize() {
+func initialize() Info {
 	// If buildVersion is empty it means the binary was NOT built through goreleaser.
 	// We try to pull version information from debug.BuildInfo().
 	if buildVersion == "" {
@@ -86,7 +82,7 @@ func initialize() {
 		panic(fmt.Sprintf(`version is not a valid semver string: "%s"`, buildVersion))
 	}
 
-	info = Info{
+	return Info{
 		ProjectName: buildProjectName,
 		Version:     buildVersion,
 
@@ -106,9 +102,10 @@ func initialize() {
 	}
 }
 
+var getInfo = sync.OnceValue(initialize)
+
 func GetInfo() Info {
-	once.Do(initialize)
-	return info
+	return getInfo()
 }
 
 func parseInt(s string) int64 {

internal/build/variables.go

@@ -1,5 +1,7 @@
 package build
 
+import "sync"
+
 var (
 	buildProjectName string = "cli"
 	buildVersion     string = ""
@@ -23,8 +25,8 @@ var (
 	buildTimestamp  string = "0"
 )
 
-// This function is used to set the build version for testing purposes.
+// SetBuildVersion sets the build version for testing purposes.
 func SetBuildVersion(version string) {
 	buildVersion = version
-	info.Version = version
+	getInfo = sync.OnceValue(initialize)
 }

libs/apps/logstream/streamer.go

@@ -347,15 +347,12 @@ func handleCloseError(err error) (bool, error) {
 }
 
 func watchContext(ctx context.Context, conn *websocket.Conn) func() {
-	var once sync.Once
 	closeCh := make(chan struct{})
 
-	closeConn := func() {
-		once.Do(func() {
-			_ = conn.WriteControl(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, "context canceled"), time.Now().Add(time.Second))
-			_ = conn.Close()
-		})
-	}
+	closeConn := sync.OnceFunc(func() {
+		_ = conn.WriteControl(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, "context canceled"), time.Now().Add(time.Second))
+		_ = conn.Close()
+	})
 
 	go func() {
 		select {

libs/apps/vite/bridge.go

@@ -83,7 +83,7 @@ type Bridge struct {
 	tunnelID           string
 	tunnelWriteChan    chan prioritizedMessage
 	stopChan           chan struct{}
-	stopOnce           sync.Once
+	stop               func()
 	httpClient         *http.Client
 	connectionRequests chan *BridgeMessage
 	port               int
@@ -101,7 +101,7 @@ func NewBridge(ctx context.Context, w *databricks.WorkspaceClient, appName strin
 		DisableCompression:  false,
 	}
 
-	return &Bridge{
+	b := &Bridge{
 		ctx:     ctx,
 		w:       w,
 		appName: appName,
@@ -114,6 +114,22 @@ func NewBridge(ctx context.Context, w *databricks.WorkspaceClient, appName strin
 		connectionRequests: make(chan *BridgeMessage, 10),
 		port:               port,
 	}
+
+	b.stop = sync.OnceFunc(func() {
+		close(b.stopChan)
+
+		if b.tunnelConn != nil {
+			_ = b.tunnelConn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
+			b.tunnelConn.Close()
+		}
+
+		if b.hmrConn != nil {
+			_ = b.hmrConn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
+			b.hmrConn.Close()
+		}
+	})
+
+	return b
 }
 
 func (vb *Bridge) getAuthHeaders(wsURL string) (http.Header, error) {
@@ -965,17 +981,5 @@ func (vb *Bridge) Start() error {
 }
 
 func (vb *Bridge) Stop() {
-	vb.stopOnce.Do(func() {
-		close(vb.stopChan)
-
-		if vb.tunnelConn != nil {
-			_ = vb.tunnelConn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
-			vb.tunnelConn.Close()
-		}
-
-		if vb.hmrConn != nil {
-			_ = vb.hmrConn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
-			vb.hmrConn.Close()
-		}
-	})
+	vb.stop()
 }

libs/cmdio/spinner.go

@@ -102,11 +102,11 @@ func (m spinnerModel) View() string {
 // The spinner automatically degrades in non-interactive terminals.
 // Context cancellation will automatically close the spinner.
 type spinner struct {
-	p    *tea.Program // nil in non-interactive mode
-	c    *cmdIO
-	ctx  context.Context
-	once sync.Once
-	done chan struct{} // Closed when tea.Program finishes
+	p        *tea.Program // nil in non-interactive mode
+	c        *cmdIO
+	ctx      context.Context
+	sendQuit func()
+	done     chan struct{} // Closed when tea.Program finishes
 }
 
 // Update sends a status message to the spinner.
@@ -121,11 +121,7 @@ func (sp *spinner) Update(msg string) {
 // It waits for the spinner to fully terminate before returning.
 // It is safe to call Close multiple times and from multiple goroutines.
 func (sp *spinner) Close() {
-	sp.once.Do(func() {
-		if sp.p != nil {
-			sp.p.Send(quitMsg{})
-		}
-	})
+	sp.sendQuit()
 	// Always wait for termination, even if we weren't the first caller
 	if sp.p != nil {
 		<-sp.done
@@ -147,7 +143,7 @@ func (sp *spinner) Close() {
 func (c *cmdIO) NewSpinner(ctx context.Context, opts ...SpinnerOption) *spinner {
 	// Don't show spinner if not interactive
 	if !c.capabilities.SupportsInteractive() {
-		return &spinner{p: nil, c: c, ctx: ctx}
+		return &spinner{p: nil, c: c, ctx: ctx, sendQuit: func() {}}
 	}
 
 	// Create model and program
@@ -167,10 +163,11 @@ func (c *cmdIO) NewSpinner(ctx context.Context, opts ...SpinnerOption) *spinner
 
 	done := make(chan struct{})
 	sp := &spinner{
-		p:    p,
-		c:    c,
-		ctx:  ctx,
-		done: done,
+		p:        p,
+		c:        c,
+		ctx:      ctx,
+		sendQuit: sync.OnceFunc(func() { p.Send(quitMsg{}) }),
+		done:     done,
 	}
 
 	// Start program in background