ref: remove init and mount channels as they aren't that useful

Author: logaretm

src/tracing.ts

@@ -1,5 +1,4 @@
 import type { H3Event } from "./event.ts";
-import type { H3Core } from "./h3.ts";
 import {
   definePlugin,
   type H3Plugin,
@@ -8,18 +7,8 @@ import {
 } from "./types/h3.ts";
 import type { EventHandler, Middleware } from "./types/handler.ts";
 
-export interface H3InitPayload {
-  app: H3Core;
-}
-
 export type HandlerType = "middleware" | "route";
 
-export interface H3MountPayload {
-  app: H3Core;
-  base: string;
-  mountedApp: unknown;
-}
-
 export interface H3THandlerTracePayload {
   event: H3Event;
   route?: string;
@@ -39,39 +28,9 @@ export interface TracingPluginOptions {
  */
 export const tracingPlugin = (traceOpts?: TracingPluginOptions): H3Plugin => {
   return definePlugin((h3) => {
-    const { tracingChannel, channel } =
+    const { tracingChannel } =
       globalThis.process.getBuiltinModule?.("diagnostics_channel") ?? {};
 
-    // Skip if diagnostics_channel is not available
-    // if channel isn't available, then tracingChannel is also not available since its built on top of it
-    if (!channel) {
-      return;
-    }
-
-    const initChannel = channel("h3.init");
-    const mountChannel = channel("h3.mount");
-
-    // Store original mount before overriding
-    const originalMount = h3.mount;
-
-    // Override the mount method to publish the mount event when a nested app is mounted.
-    h3.mount = (base, input) => {
-      if (mountChannel.hasSubscribers) {
-        mountChannel.publish({
-          app: h3,
-          base,
-          mountedApp: input,
-        } satisfies H3MountPayload);
-      }
-
-      return originalMount.call(h3, base, input);
-    };
-
-    // Publish the init event ASAP
-    if (initChannel.hasSubscribers) {
-      initChannel.publish({ app: h3 } satisfies H3InitPayload);
-    }
-
     // If tracingChannel is not available, then we can't trace request handlers
     if (!tracingChannel) {
       return;
@@ -169,6 +128,8 @@ export const tracingPlugin = (traceOpts?: TracingPluginOptions): H3Plugin => {
       return originalUse.call(h3, wrapMiddleware(fn), opts);
     };
 
+    // TODO: Trace mount
+
     return h3;
   })();
 };

test/tracing.test.ts

@@ -1,12 +1,6 @@
-import { channel, tracingChannel } from "node:diagnostics_channel";
-import { describeMatrix } from "./_setup.ts";
-import { H3 } from "../src/h3.ts";
-import {
-  type H3InitPayload,
-  type H3MountPayload,
-  type H3THandlerTracePayload,
-  tracingPlugin,
-} from "../src/tracing.ts";
+import { tracingChannel } from "node:diagnostics_channel";
+import { describeMatrix, type TestOptions } from "./_setup.ts";
+import { type H3THandlerTracePayload } from "../src/tracing.ts";
 
 type TracingEvent = {
   start?: { data: H3THandlerTracePayload };
@@ -16,14 +10,6 @@ type TracingEvent = {
   error?: { data: H3THandlerTracePayload; error: Error };
 };
 
-function createH3WithTracing() {
-  const app = new H3({
-    plugins: [tracingPlugin()],
-  });
-
-  return app;
-}
-
 function createTracingListener() {
   const events: TracingEvent[] = [];
 
@@ -69,111 +55,12 @@ function createTracingListener() {
   };
 }
 
+// Matrix is configured with tracing plugin enabled
+const testOpts: TestOptions = { tracing: true };
+
 describeMatrix(
   "tracing channels",
   (t, { it, expect }) => {
-    it("h3.init channel fires when app is initialized", async () => {
-      const events: H3InitPayload[] = [];
-      const initChannel = channel("h3.init");
-
-      const handler = (message: unknown) => {
-        events.push(message as H3InitPayload);
-      };
-      initChannel.subscribe(handler);
-
-      try {
-        const app = createH3WithTracing();
-        expect(events).toHaveLength(1);
-        expect(events[0].app).toBe(app);
-      } finally {
-        initChannel.unsubscribe(handler);
-      }
-    });
-
-    it("h3.init listener can configure global error handler", async () => {
-      const initChannel = channel("h3.init");
-
-      const customError = (error: any) => {
-        return new Response(
-          JSON.stringify({ custom: true, message: error.message }),
-          {
-            status: error.status || 500,
-            headers: { "content-type": "application/json" },
-          },
-        );
-      };
-
-      const handler = (message: unknown) => {
-        const { app } = message as H3InitPayload;
-        app.config.onError = customError;
-      };
-      initChannel.subscribe(handler);
-
-      try {
-        const app = createH3WithTracing();
-        app.get("/error", () => {
-          throw new Error("Test error");
-        });
-
-        const res = await app.request("/error");
-        expect(res.status).toBe(500);
-        const body = await res.json();
-        expect(body.custom).toBe(true);
-        expect(body.message).toBe("Test error");
-      } finally {
-        initChannel.unsubscribe(handler);
-      }
-    });
-
-    it("h3.mount channel fires when nested app is mounted", async () => {
-      const events: H3MountPayload[] = [];
-      const mountChannel = channel("h3.mount");
-
-      const handler = (message: unknown) => {
-        events.push(message as H3MountPayload);
-      };
-      mountChannel.subscribe(handler);
-
-      try {
-        const nestedApp = createH3WithTracing();
-        nestedApp.get("/test", () => "nested");
-
-        t.app.mount("/api", nestedApp);
-
-        expect(events).toHaveLength(1);
-        expect(events[0].app).toBe(t.app);
-        expect(events[0].base).toBe("/api");
-        expect(events[0].mountedApp).toBe(nestedApp);
-      } finally {
-        mountChannel.unsubscribe(handler);
-      }
-    });
-
-    it("h3.mount channel fires for fetchable objects", async () => {
-      const events: H3MountPayload[] = [];
-      const mountChannel = channel("h3.mount");
-
-      const handler = (message: unknown) => {
-        events.push(message as H3MountPayload);
-      };
-      mountChannel.subscribe(handler);
-
-      try {
-        const fetchHandler = {
-          fetch: () => new Response("fetchable"),
-        };
-
-        t.app.mount("/fetch", fetchHandler);
-
-        expect(events).toHaveLength(1);
-        expect(events[0].app).toBe(t.app);
-        expect(events[0].base).toBe("/fetch");
-        expect(events[0].mountedApp).toBe(fetchHandler);
-      } finally {
-        mountChannel.unsubscribe(handler);
-      }
-    });
-
     it("tracing channels fire for handlers", async () => {
       const listener = createTracingListener();
 
@@ -466,5 +353,5 @@ describeMatrix(
       }
     });
   },
-  { tracing: true },
+  testOpts,
 );