fix: trace decorator's types

Author: le0m

packages/utils/src/lib/server/cache/base.ts

@@ -1,6 +1,6 @@
 import type { JitterFn, JitterMode } from '../../utils/misc.js';
 import type { StorageReadWriter } from '../storage.js';
-import { trace, ATTR_PEER_SERVICE } from '../telemetry.js';
+import { ATTR_PEER_SERVICE, trace } from '../telemetry.js';
 import { SpanKind } from '@opentelemetry/api';
 
 /**

packages/utils/src/lib/server/index.ts

@@ -2,6 +2,7 @@ export * from './cache/index.js';
 export * from './hooks/index.js';
 export * from './session.js';
 export * from './sitemap.js';
+export { traceDecoratorFactory, ATTR_PEER_SERVICE } from './telemetry.js';
 export * from './utils.js';
 
 import type { Session } from './session.js';

packages/utils/src/lib/server/telemetry.ts

@@ -6,36 +6,56 @@ import api, { type Span, type SpanOptions, SpanStatusCode } from '@opentelemetry
  */
 export const ATTR_PEER_SERVICE = 'peer.service' as const;
 
-export const tracer = api.trace.getTracer('@chialab/sveltekit-utils');
+export const traceDecoratorFactory = (name: string, version?: string) => {
+	const tracer = api.trace.getTracer(name, version);
 
-/**
- * Decorator to trace a method or function by wrapping it in a new active span.
- *
- * @param options Span options
- */
-export const trace =
-	(options: SpanOptions = {}) =>
-	(_: any, method: PropertyKey, descriptor: PropertyDescriptor) => ({
-		...descriptor,
-		value(...args: any[]) {
-			return tracer.startActiveSpan(
-				[this?.constructor?.name, method].filter(Boolean).join('.'),
-				options,
-				async (span: Span) => {
+	return <This, Value extends (this: This, ...args: any) => unknown>(options: SpanOptions = {}) =>
+		(target: Value, ctx: ClassMethodDecoratorContext<This, Value>): Value => {
+			type R = ReturnType<Value>;
+
+			return function (this: This, ...args: Parameters<Value>): R {
+				// @ts-expect-error Typing this properly would be cumbersome.
+				const className = ctx.static ? this.name : this.constructor.name;
+
+				return tracer.startActiveSpan([className, ctx.name].filter(Boolean).join('.'), options, (span: Span): R => {
 					try {
-						// Wait for the wrapped function to end before closing the span and returning
-						return await descriptor.value.call(this, ...args);
-					} catch (e) {
+						const result = target.call(this, ...args) as R;
+						if (result && typeof result === 'object' && 'then' in result && typeof result.then === 'function') {
+							return result.then(
+								(result: R) => {
+									span.end();
+
+									return result;
+								},
+								(err: unknown) => {
+									span.setStatus({ code: SpanStatusCode.ERROR });
+									if (err instanceof Error) {
+										span.recordException(err);
+									}
+									span.end();
+
+									throw err;
+								},
+							);
+						}
+
+						return result;
+					} catch (err: unknown) {
 						span.setStatus({ code: SpanStatusCode.ERROR });
-						if (e instanceof Error) {
-							span.recordException(e);
+						if (err instanceof Error) {
+							span.recordException(err);
 						}
 
-						throw e;
+						throw err;
 					} finally {
 						span.end();
 					}
-				},
-			);
-		},
-	});
+				});
+			} as Value;
+		};
+};
+
+/**
+ * Decorator to trace a method or function by wrapping it in a new active span.
+ */
+export const trace = traceDecoratorFactory('@chialab/sveltekit-utils');

packages/utils/tsconfig.json

@@ -4,13 +4,13 @@
 		"allowJs": true,
 		"checkJs": true,
 		"esModuleInterop": true,
-		"experimentalDecorators": true,
 		"forceConsistentCasingInFileNames": true,
 		"moduleResolution": "Bundler",
 		"resolveJsonModule": true,
 		"skipLibCheck": true,
 		"sourceMap": true,
-		"strict": true
+		"strict": true,
+		"target": "es2022"
 	},
 	"exclude": ["./tests/coverage/**"]
 	// Path aliases are handled by https://kit.svelte.dev/docs/configuration#alias