chore: rename FromSlog to NewCustomLogger

This is more in line with the existing zerolog-focused API.

Also update a couple more comments, and add a test for the With method.

log/README.md

@@ -2,4 +2,4 @@
 
 The `cosmossdk.io/log` provides a zerolog logging implementation for the Cosmos SDK and Cosmos SDK modules.
 
-To use a logger backed by an instance of the standard library's `log/slog` package, use `cosmossdk.io/log/slog`.
+To use a logger wrapping an instance of the standard library's `log/slog` package, use `cosmossdk.io/log/slog`.

log/slog/logger.go

@@ -16,8 +16,11 @@ type Logger struct {
 	log *slog.Logger
 }
 
-// FromSlog returns a Logger backed by an existing slog.Logger instance.
-func FromSlog(log *slog.Logger) Logger {
+// NewCustomLogger returns a Logger backed by an existing slog.Logger instance.
+// All logging methods are called directly on the *slog.Logger;
+// therefore it is the caller's responsibility to configure message filtering,
+// level filtering, output format, and so on.
+func NewCustomLogger(log *slog.Logger) Logger {
 	return Logger{log: log}
 }
 

log/slog/logger_test.go

@@ -14,7 +14,7 @@ func TestSlog(t *testing.T) {
 	h := stdslog.NewJSONHandler(&buf, &stdslog.HandlerOptions{
 		Level: stdslog.LevelDebug,
 	})
-	logger := slog.FromSlog(stdslog.New(h))
+	logger := slog.NewCustomLogger(stdslog.New(h))
 
 	type logLine struct {
 		Level string `json:"level"`
@@ -74,4 +74,19 @@ func TestSlog(t *testing.T) {
 	}); want != line {
 		t.Fatalf("unexpected log record: want %v, got %v", want, line)
 	}
+
+	wLogger := logger.With("num", 5)
+	buf.Reset()
+	wLogger.Info("Using .With")
+
+	if err := json.Unmarshal(buf.Bytes(), &line); err != nil {
+		t.Fatal(err)
+	}
+	if want := (logLine{
+		Level: stdslog.LevelInfo.String(),
+		Msg:   "Using .With",
+		Num:   5,
+	}); want != line {
+		t.Fatalf("unexpected log record: want %v, got %v", want, line)
+	}
 }