fix #3552: calling stop() now clears go timeouts

CHANGELOG.md

@@ -89,6 +89,12 @@
     new Foo();
     ```
 
+* Terminate the Go GC when esbuild's `stop()` API is called ([#3552](https://github.com/evanw/esbuild/issues/3552))
+
+    If you use esbuild with WebAssembly and pass the `worker: false` flag to `esbuild.initialize()`, then esbuild will run the WebAssembly module on the main thread. If you do this within a Deno test and that test calls `esbuild.stop()` to clean up esbuild's resources, Deno may complain that a `setTimeout()` call lasted past the end of the test. This happens when the Go is in the middle of a garbage collection pass and has scheduled additional ongoing garbage collection work. Normally calling `esbuild.stop()` will terminate the web worker that the WebAssembly module runs in, which will terminate the Go GC, but that doesn't happen if you disable the web worker with `worker: false`.
+
+    With this release, esbuild will now attempt to terminate the Go GC in this edge case by calling `clearTimeout()` on these pending timeouts.
+
 ## 0.19.9
 
 * Add support for transforming new CSS gradient syntax for older browsers

lib/deno/wasm.ts

@@ -2,9 +2,13 @@ import type * as types from "../shared/types"
 import * as common from "../shared/common"
 import * as ourselves from "./wasm"
 
+interface Go {
+  _scheduledTimeouts: Map<number, ReturnType<typeof setTimeout>>
+}
+
 declare const ESBUILD_VERSION: string
 declare let WEB_WORKER_SOURCE_CODE: string
-declare let WEB_WORKER_FUNCTION: (postMessage: (data: Uint8Array) => void) => (event: { data: Uint8Array | ArrayBuffer | WebAssembly.Module }) => void
+declare let WEB_WORKER_FUNCTION: (postMessage: (data: Uint8Array) => void) => (event: { data: Uint8Array | ArrayBuffer | WebAssembly.Module }) => Go
 
 export let version = ESBUILD_VERSION
 
@@ -91,10 +95,14 @@ const startRunningService = async (wasmURL: string | URL, wasmModule: WebAssembl
   } else {
     // Run esbuild on the main thread
     let onmessage = WEB_WORKER_FUNCTION((data: Uint8Array) => worker.onmessage!({ data }))
+    let go: Go | undefined
     worker = {
       onmessage: null,
-      postMessage: data => setTimeout(() => onmessage({ data })),
+      postMessage: data => setTimeout(() => go = onmessage({ data })),
       terminate() {
+        if (go)
+          for (let timeout of go._scheduledTimeouts.values())
+            clearTimeout(timeout)
       },
     }
   }

lib/npm/browser.ts

@@ -2,9 +2,13 @@ import type * as types from "../shared/types"
 import * as common from "../shared/common"
 import * as ourselves from "./browser"
 
+interface Go {
+  _scheduledTimeouts: Map<number, ReturnType<typeof setTimeout>>
+}
+
 declare const ESBUILD_VERSION: string
 declare let WEB_WORKER_SOURCE_CODE: string
-declare let WEB_WORKER_FUNCTION: (postMessage: (data: Uint8Array) => void) => (event: { data: Uint8Array | ArrayBuffer | WebAssembly.Module }) => void
+declare let WEB_WORKER_FUNCTION: (postMessage: (data: Uint8Array) => void) => (event: { data: Uint8Array | ArrayBuffer | WebAssembly.Module }) => Go
 
 export let version = ESBUILD_VERSION
 
@@ -85,10 +89,14 @@ const startRunningService = async (wasmURL: string | URL, wasmModule: WebAssembl
   } else {
     // Run esbuild on the main thread
     let onmessage = WEB_WORKER_FUNCTION((data: Uint8Array) => worker.onmessage!({ data }))
+    let go: Go | undefined
     worker = {
       onmessage: null,
-      postMessage: data => setTimeout(() => onmessage({ data })),
+      postMessage: data => setTimeout(() => go = onmessage({ data })),
       terminate() {
+        if (go)
+          for (let timeout of go._scheduledTimeouts.values())
+            clearTimeout(timeout)
       },
     }
   }

lib/shared/worker.ts

@@ -37,6 +37,7 @@ onmessage = ({ data: wasm }: { data: WebAssembly.Module | string }) => {
       stdin.push(data)
       if (resumeStdin) resumeStdin()
     }
+    return go
   }
 
   fs.read = (
@@ -76,6 +77,8 @@ onmessage = ({ data: wasm }: { data: WebAssembly.Module | string }) => {
       postMessage(error)
     },
   )
+
+  return go
 }
 
 async function tryToInstantiateModule(wasm: WebAssembly.Module | string, go: Go): Promise<WebAssembly.Instance> {

scripts/deno-tests.js

@@ -25,10 +25,6 @@ function test(name, backends, fn) {
       promise.then(cancel, cancel)
       promise.then(resolve, reject)
     }),
-
-    // It's ok that the Go WebAssembly runtime uses "setTimeout"
-    sanitizeResources: false,
-    sanitizeOps: false,
   })
 
   for (const backend of backends) {