✨ Add library logger facades

src/BitLogger_test.mbt

@@ -770,3 +770,57 @@ test "configured queued file logger flushes queue through file helper" {
     inspect(logger.file_close(), content="false")
   }
 }
+
+test "library logger keeps a smaller stable facade" {
+  let captured_target : Ref[String] = Ref::new("")
+  let captured_message : Ref[String] = Ref::new("")
+  let captured_fields : Ref[Array[Field]] = Ref::new([])
+  let logger = LibraryLogger::new(
+    callback_sink(fn(rec) {
+      captured_target.val = rec.target
+      captured_message.val = rec.message
+      captured_fields.val = rec.fields
+    }),
+    min_level=Level::Info,
+    target="svc",
+  ).with_context_fields([field("service", "bitlogger")]).child("worker")
+  logger.info("ready", fields=[field("mode", "test")])
+  inspect(captured_target.val, content="svc.worker")
+  inspect(captured_message.val, content="ready")
+  inspect(captured_fields.val.length(), content="2")
+  inspect(captured_fields.val[0].key, content="service")
+  inspect(captured_fields.val[1].key, content="mode")
+}
+
+test "library logger can unwrap to full logger when needed" {
+  let base = LibraryLogger::new(console_sink(), min_level=Level::Warn, target="lib")
+  let full = base.to_logger().with_timestamp()
+  inspect(base.is_enabled(Level::Error), content="true")
+  inspect(base.is_enabled(Level::Info), content="false")
+  inspect(full.timestamp, content="true")
+  inspect(full.target, content="lib")
+}
+
+test "library logger can be built from configured runtime path" {
+  let logger = build_library_logger(
+    LoggerConfig::new(
+      min_level=Level::Warn,
+      target="lib.config",
+      sink=SinkConfig::new(kind=SinkKind::Console),
+    ),
+  )
+  let full = logger.to_logger()
+  inspect(logger.is_enabled(Level::Error), content="true")
+  inspect(logger.is_enabled(Level::Info), content="false")
+  inspect(full.target, content="lib.config")
+}
+
+test "library logger can be parsed and built from config text" {
+  let logger = parse_and_build_library_logger(
+    "{\"min_level\":\"warn\",\"target\":\"lib.json\",\"sink\":{\"kind\":\"console\"}}",
+  )
+  let full = logger.to_logger()
+  inspect(logger.is_enabled(Level::Error), content="true")
+  inspect(logger.is_enabled(Level::Info), content="false")
+  inspect(full.target, content="lib.json")
+}

src/library_logger.mbt

@@ -0,0 +1,97 @@
+pub struct LibraryLogger[S] {
+  inner : Logger[S]
+}
+
+pub fn[S] library_logger(logger : Logger[S]) -> LibraryLogger[S] {
+  { inner: logger }
+}
+
+pub fn[S] LibraryLogger::new(
+  sink : S,
+  min_level~ : Level = Level::Info,
+  target~ : String = "",
+) -> LibraryLogger[S] {
+  library_logger(Logger::new(sink, min_level=min_level, target=target))
+}
+
+pub fn[S] LibraryLogger::to_logger(self : LibraryLogger[S]) -> Logger[S] {
+  self.inner
+}
+
+pub fn configured_library_logger(logger : ConfiguredLogger) -> LibraryLogger[RuntimeSink] {
+  library_logger(logger)
+}
+
+pub fn build_library_logger(config : LoggerConfig) -> LibraryLogger[RuntimeSink] {
+  configured_library_logger(build_logger(config))
+}
+
+pub fn parse_and_build_library_logger(
+  input : String,
+) -> LibraryLogger[RuntimeSink] raise ConfigError {
+  configured_library_logger(parse_and_build_logger(input))
+}
+
+pub fn[S] LibraryLogger::with_target(self : LibraryLogger[S], target : String) -> LibraryLogger[S] {
+  library_logger(self.inner.with_target(target))
+}
+
+pub fn[S] LibraryLogger::child(self : LibraryLogger[S], target : String) -> LibraryLogger[S] {
+  library_logger(self.inner.child(target))
+}
+
+pub fn[S] LibraryLogger::with_context_fields(
+  self : LibraryLogger[S],
+  fields : Array[Field],
+) -> LibraryLogger[ContextSink[S]] {
+  library_logger(self.inner.with_context_fields(fields))
+}
+
+pub fn[S] LibraryLogger::bind(
+  self : LibraryLogger[S],
+  fields : Array[Field],
+) -> LibraryLogger[ContextSink[S]] {
+  self.with_context_fields(fields)
+}
+
+pub fn[S] LibraryLogger::is_enabled(self : LibraryLogger[S], level : Level) -> Bool {
+  self.inner.is_enabled(level)
+}
+
+pub fn[S : Sink] LibraryLogger::log(
+  self : LibraryLogger[S],
+  level : Level,
+  message : String,
+  fields~ : Array[Field] = [],
+  target? : String = "",
+) -> Unit {
+  self.inner.log(level, message, fields=fields, target=target)
+}
+
+pub fn[S : Sink] LibraryLogger::info(
+  self : LibraryLogger[S],
+  message : String,
+  fields~ : Array[Field] = [],
+) -> Unit {
+  self.inner.info(message, fields=fields)
+}
+
+pub fn[S : Sink] LibraryLogger::warn(
+  self : LibraryLogger[S],
+  message : String,
+  fields~ : Array[Field] = [],
+) -> Unit {
+  self.inner.warn(message, fields=fields)
+}
+
+pub fn[S : Sink] LibraryLogger::error(
+  self : LibraryLogger[S],
+  message : String,
+  fields~ : Array[Field] = [],
+) -> Unit {
+  self.inner.error(message, fields=fields)
+}
+
+pub fn default_library_logger() -> LibraryLogger[ConsoleSink] {
+  library_logger(default_logger())
+}