refactor(loghelper): unify nil-safe logger initialization fallback

.claude/rules/logging-conventions.md

@@ -119,12 +119,12 @@ The one documented exception is `MemorySearch`'s `query` field — it's small, u
 
 ## 5. Nil-Logger Safety ★
 
-Library code — anything in `pkg/` — must accept a `nil` logger and behave silently. Two project conventions for the fallback:
+Library code — anything in `pkg/` — must accept a `nil` logger and behave silently. The two project conventions for the fallback are encoded once in `internal/loghelper`; **call the helper, never inline the `if logger == nil` block**:
 
-| Where | Fallback | Why |
+| Where | Helper | Why |
 |---|---|---|
-| `pkg/` libraries (`mcp`, `temperature`) | `slog.New(slog.DiscardHandler)` | Tests and embedders may not want output |
-| CLI-time code (`pkg/compiler` when invoked directly) | `slog.Default()` | Users running `remindb compile` want feedback |
+| `pkg/` libraries (`mcp`, `temperature`) | `loghelper.OrDiscard(l)` → `slog.New(slog.DiscardHandler)` | Tests and embedders may not want output |
+| CLI-time code (`pkg/compiler` when invoked directly) | `loghelper.OrDefault(l)` → `slog.Default()` | Users running `remindb compile` want feedback |
 
 ```go
 // Bad — assumes the caller passed a non-nil logger
@@ -134,26 +134,28 @@ func NewServer(st *store.Store, ..., logger *slog.Logger) *Server {
     return s
 }
 
-// Good — pkg/ library default
+// Bad — inlining the fallback; it now lives in one place
 func NewServer(st *store.Store, ..., logger *slog.Logger) *Server {
     if logger == nil {
         logger = slog.New(slog.DiscardHandler)
     }
     return &Server{logger: logger, ...}
 }
 
+// Good — pkg/ library default
+func NewServer(st *store.Store, ..., logger *slog.Logger) *Server {
+    return &Server{logger: loghelper.OrDiscard(logger), ...}
+}
+
 // Good — CLI-time default (used only when the call is the entry point)
 func Run(ctx context.Context, st *store.Store, opts ...Option) error {
     o := applyOptions(opts...)
-    logger := o.logger
-    if logger == nil {
-        logger = slog.Default()
-    }
+    logger := loghelper.OrDefault(o.logger)
     ...
 }
 ```
 
-See `pkg/mcp/server.go:26-28` and `pkg/temperature/tracker.go:30-32` for the discard pattern; `pkg/compiler/compiler.go:63-66` for the default pattern.
+`internal/loghelper/loghelper.go` is the canonical implementation of both conventions; every `pkg/` site resolves through it (`OrDiscard` for libraries, `OrDefault` for CLI-entry code). No `pkg/` file should still inline `if logger == nil { logger = slog.New(...) }`.
 
 ---
 

internal/loghelper/loghelper.go

@@ -0,0 +1,17 @@
+package loghelper
+
+import "log/slog"
+
+func OrDiscard(l *slog.Logger) *slog.Logger {
+	if l == nil {
+		return slog.New(slog.DiscardHandler)
+	}
+	return l
+}
+
+func OrDefault(l *slog.Logger) *slog.Logger {
+	if l == nil {
+		return slog.Default()
+	}
+	return l
+}

internal/loghelper/loghelper_test.go

@@ -0,0 +1,29 @@
+package loghelper
+
+import (
+	"log/slog"
+	"testing"
+)
+
+func TestOrDiscard(t *testing.T) {
+	if got := OrDiscard(nil); got == nil {
+		t.Fatal("OrDiscard(nil) returned nil")
+	}
+	OrDiscard(nil).Info("must not panic")
+
+	l := slog.New(slog.DiscardHandler)
+	if got := OrDiscard(l); got != l {
+		t.Errorf("OrDiscard(l) = %p, want identity %p", got, l)
+	}
+}
+
+func TestOrDefault(t *testing.T) {
+	if got := OrDefault(nil); got != slog.Default() {
+		t.Errorf("OrDefault(nil) = %p, want slog.Default() %p", got, slog.Default())
+	}
+
+	l := slog.New(slog.DiscardHandler)
+	if got := OrDefault(l); got != l {
+		t.Errorf("OrDefault(l) = %p, want identity %p", got, l)
+	}
+}

pkg/compiler/compiler.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/radimsem/remindb/internal/fileext"
 	"github.com/radimsem/remindb/internal/ignore"
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/internal/redaction"
 	"github.com/radimsem/remindb/internal/tempfile"
 	"github.com/radimsem/remindb/pkg/config"
@@ -131,10 +132,7 @@ func Compile(ctx context.Context, st *store.Store, opts ...Option) (*Result, err
 		opt(&o)
 	}
 
-	logger := o.logger
-	if logger == nil {
-		logger = slog.Default()
-	}
+	logger := loghelper.OrDefault(o.logger)
 
 	ctx, cancel := withTimeout(ctx, o.timeout)
 	defer cancel()

pkg/mcp/initial.go

@@ -5,15 +5,14 @@ import (
 	"fmt"
 	"log/slog"
 
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/pkg/compiler"
 	"github.com/radimsem/remindb/pkg/store"
 )
 
 // Run an initial compile when the store is empty; no-op otherwise.
 func MaybeInitialCompile(ctx context.Context, st *store.Store, dir string, logger *slog.Logger) error {
-	if logger == nil {
-		logger = slog.New(slog.DiscardHandler)
-	}
+	logger = loghelper.OrDiscard(logger)
 
 	stats, err := st.GetStats(ctx)
 	if err != nil {

pkg/mcp/ledger/ledger.go

@@ -15,6 +15,7 @@ import (
 	"sync"
 
 	"github.com/radimsem/remindb/internal/contentid"
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/pkg/config"
 	"github.com/radimsem/remindb/pkg/mcp/jsonlsink"
 )
@@ -64,9 +65,7 @@ type Ledger struct {
 
 // New opens (and compacts) the ledger under <workspace>/.remindb/sessions.
 func New(workspace string, logger *slog.Logger) (*Ledger, error) {
-	if logger == nil {
-		logger = slog.New(slog.DiscardHandler)
-	}
+	logger = loghelper.OrDiscard(logger)
 	dir := filepath.Join(workspace, config.DirName, subDir)
 
 	// growth bounded by compact(), not rotation

pkg/mcp/notify/notify.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	mcp "github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/pkg/config"
 	"github.com/radimsem/remindb/pkg/mcp/resources"
 )
@@ -31,9 +32,7 @@ type Publisher struct {
 }
 
 func NewPublisher(cfg config.ResourcesConfig, logger *slog.Logger) (*Publisher, error) {
-	if logger == nil {
-		logger = slog.New(slog.DiscardHandler)
-	}
+	logger = loghelper.OrDiscard(logger)
 
 	def := DefaultDebounce
 	if cfg.Debounce != nil {

pkg/mcp/rescan.go

@@ -15,6 +15,7 @@ import (
 	"github.com/radimsem/remindb/internal/contentid"
 	"github.com/radimsem/remindb/internal/fileext"
 	"github.com/radimsem/remindb/internal/ignore"
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/pkg/compiler"
 	"github.com/radimsem/remindb/pkg/config"
 	"github.com/radimsem/remindb/pkg/diff"
@@ -64,9 +65,7 @@ func NewRescanLoop(st *store.Store, dir string, interval time.Duration, cc confi
 	if interval <= 0 {
 		interval = defaultRescanInterval
 	}
-	if logger == nil {
-		logger = slog.New(slog.DiscardHandler)
-	}
+	logger = loghelper.OrDiscard(logger)
 	if status == nil {
 		status = rescanstat.New()
 	}

pkg/mcp/server.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/internal/redaction"
 	"github.com/radimsem/remindb/pkg/config"
 	"github.com/radimsem/remindb/pkg/logbuf"
@@ -102,10 +103,7 @@ func NewServer(st *store.Store, tracker *temperature.Tracker, cfg temperature.Co
 		opt(&o)
 	}
 
-	logger := o.logger
-	if logger == nil {
-		logger = slog.New(slog.DiscardHandler)
-	}
+	logger := loghelper.OrDiscard(o.logger)
 
 	transport := o.transport
 	if transport == "" {

pkg/mcp/session/registry.go

@@ -11,6 +11,7 @@ import (
 
 	gomcp "github.com/modelcontextprotocol/go-sdk/mcp"
 	"github.com/radimsem/remindb/internal/contentid"
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/pkg/mcp/ledger"
 	"github.com/radimsem/remindb/pkg/mcp/sessionlog"
 )
@@ -59,9 +60,7 @@ type Registry struct {
 
 // NewRegistry tracks live sessions; l (may be nil) persists their metrics.
 func NewRegistry(srv *gomcp.Server, transport, listen string, l *ledger.Ledger, logger *slog.Logger) *Registry {
-	if logger == nil {
-		logger = slog.New(slog.DiscardHandler)
-	}
+	logger = loghelper.OrDiscard(logger)
 
 	return &Registry{
 		srv:       srv,

pkg/temperature/tracker.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/radimsem/remindb/internal/contentid"
+	"github.com/radimsem/remindb/internal/loghelper"
 	"github.com/radimsem/remindb/pkg/config"
 	"github.com/radimsem/remindb/pkg/store"
 )
@@ -49,9 +50,7 @@ func NewTracker(s NodeStore, dir string, bootstrap Config, logger *slog.Logger)
 		return nil, fmt.Errorf("invalid config: %w", err)
 	}
 
-	if logger == nil {
-		logger = slog.New(slog.DiscardHandler)
-	}
+	logger = loghelper.OrDiscard(logger)
 	return &Tracker{
 		store:            s,
 		bootstrap:        bootstrap,