feat: normalise declarative store config defaults

Co-Authored-By: Virgil <virgil@lethean.io>

doc.go

@@ -14,7 +14,9 @@
 // journal, purge interval, or workspace state directory are already known.
 // Prefer the struct literal over `store.New(..., store.WithJournal(...))`
 // when the full configuration is already available, because it reads as data
-// rather than a chain of steps. Use
+// rather than a chain of steps. Use `StoreConfig.Normalised()` when you want
+// the default purge interval and workspace state directory filled in before
+// you pass the config onward. Use
 // `store.WithWorkspaceStateDirectory("/tmp/core-state")` only when the
 // workspace path is assembled incrementally rather than declared up front.
 //

store.go

@@ -25,6 +25,7 @@ const (
 	entryGroupColumn        = "group_name"
 	entryKeyColumn          = "entry_key"
 	entryValueColumn        = "entry_value"
+	defaultPurgeInterval    = 60 * time.Second
 )
 
 // Usage example: `storeInstance, err := store.NewConfigured(store.StoreConfig{DatabasePath: "/tmp/go-store.db", Journal: store.JournalConfiguration{EndpointURL: "http://127.0.0.1:8086", Organisation: "core", BucketName: "events"}, PurgeInterval: 30 * time.Second})`
@@ -46,6 +47,19 @@ type StoreConfig struct {
 	WorkspaceStateDirectory string
 }
 
+// Usage example: `config := (store.StoreConfig{DatabasePath: ":memory:"}).Normalised(); fmt.Println(config.PurgeInterval, config.WorkspaceStateDirectory)`
+func (storeConfig StoreConfig) Normalised() StoreConfig {
+	if storeConfig.PurgeInterval == 0 {
+		storeConfig.PurgeInterval = defaultPurgeInterval
+	}
+	if storeConfig.WorkspaceStateDirectory == "" {
+		storeConfig.WorkspaceStateDirectory = normaliseWorkspaceStateDirectory(defaultWorkspaceStateDirectory)
+	} else {
+		storeConfig.WorkspaceStateDirectory = normaliseWorkspaceStateDirectory(storeConfig.WorkspaceStateDirectory)
+	}
+	return storeConfig
+}
+
 // Usage example: `if err := (store.StoreConfig{DatabasePath: ":memory:", PurgeInterval: 30 * time.Second}).Validate(); err != nil { return }`
 func (storeConfig StoreConfig) Validate() error {
 	if storeConfig.DatabasePath == "" {
@@ -265,6 +279,7 @@ func openConfiguredStore(operation string, storeConfig StoreConfig) (*Store, err
 	if err := storeConfig.Validate(); err != nil {
 		return nil, core.E(operation, "validate config", err)
 	}
+	storeConfig = storeConfig.Normalised()
 
 	storeInstance, err := openSQLiteStore(operation, storeConfig.DatabasePath)
 	if err != nil {
@@ -274,12 +289,8 @@ func openConfiguredStore(operation string, storeConfig StoreConfig) (*Store, err
 	if storeConfig.Journal != (JournalConfiguration{}) {
 		storeInstance.journalConfiguration = storeConfig.Journal
 	}
-	if storeConfig.PurgeInterval > 0 {
-		storeInstance.purgeInterval = storeConfig.PurgeInterval
-	}
-	if storeConfig.WorkspaceStateDirectory != "" {
-		storeInstance.workspaceStateDirectory = normaliseWorkspaceStateDirectory(storeConfig.WorkspaceStateDirectory)
-	}
+	storeInstance.purgeInterval = storeConfig.PurgeInterval
+	storeInstance.workspaceStateDirectory = storeConfig.WorkspaceStateDirectory
 
 	// New() performs a non-destructive orphan scan so callers can discover
 	// leftover workspaces via RecoverOrphans().
@@ -329,7 +340,7 @@ func openSQLiteStore(operation, databasePath string) (*Store, error) {
 		workspaceStateDirectory: normaliseWorkspaceStateDirectory(defaultWorkspaceStateDirectory),
 		purgeContext:            purgeContext,
 		cancelPurge:             cancel,
-		purgeInterval:           60 * time.Second,
+		purgeInterval:           defaultPurgeInterval,
 		watchers:                make(map[string][]chan Event),
 	}, nil
 }
@@ -839,7 +850,7 @@ func (storeInstance *Store) startBackgroundPurge() {
 		return
 	}
 	if storeInstance.purgeInterval <= 0 {
-		storeInstance.purgeInterval = 60 * time.Second
+		storeInstance.purgeInterval = defaultPurgeInterval
 	}
 	purgeInterval := storeInstance.purgeInterval
 

store_test.go

@@ -152,6 +152,7 @@ func TestStore_WorkspaceStateDirectory_Good_Default(t *testing.T) {
 
 	assert.Equal(t, normaliseWorkspaceStateDirectory(defaultWorkspaceStateDirectory), storeInstance.WorkspaceStateDirectory())
 	assert.Equal(t, storeInstance.WorkspaceStateDirectory(), storeInstance.Config().WorkspaceStateDirectory)
+	assert.Equal(t, defaultPurgeInterval, storeInstance.Config().PurgeInterval)
 }
 
 func TestStore_JournalConfiguration_Good(t *testing.T) {
@@ -244,6 +245,23 @@ func TestStore_StoreConfig_Good_Validate(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestStore_StoreConfig_Good_NormalisedDefaults(t *testing.T) {
+	normalisedConfig := (StoreConfig{DatabasePath: ":memory:"}).Normalised()
+
+	assert.Equal(t, ":memory:", normalisedConfig.DatabasePath)
+	assert.Equal(t, defaultPurgeInterval, normalisedConfig.PurgeInterval)
+	assert.Equal(t, normaliseWorkspaceStateDirectory(defaultWorkspaceStateDirectory), normalisedConfig.WorkspaceStateDirectory)
+}
+
+func TestStore_StoreConfig_Good_NormalisedWorkspaceStateDirectory(t *testing.T) {
+	normalisedConfig := (StoreConfig{
+		DatabasePath:            ":memory:",
+		WorkspaceStateDirectory: ".core/state///",
+	}).Normalised()
+
+	assert.Equal(t, ".core/state", normalisedConfig.WorkspaceStateDirectory)
+}
+
 func TestStore_StoreConfig_Bad_NegativePurgeInterval(t *testing.T) {
 	err := (StoreConfig{
 		DatabasePath:  ":memory:",