fixup! async_hooks: add AsyncResource.bind utility

nodejs · Aug 4, 2020 · 1432c48 · 1432c48
1 parent 6c6bdf8
commit 1432c48
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Showing 3 changed files with 32 additions and 2 deletions.
diff --git a/doc/api/async_hooks.md b/doc/api/async_hooks.md
@@ -740,6 +740,9 @@ added: REPLACEME
 
 Binds the given function to the current execution context.
 
+The returned function will have an `asyncResource` property referencing
+the `AsyncResource` to which the function is bound.
+
 #### `asyncResource.bind(fn)`
 <!-- YAML
 added: REPLACEME
@@ -749,6 +752,9 @@ added: REPLACEME
 
 Binds the given function to execute to this `AsyncResource`'s scope.
 
+The returned function will have an `asyncResource` property referencing
+the `AsyncResource` to which the function is bound.
+
 #### `asyncResource.runInAsyncScope(fn[, thisArg, ...args])`
 <!-- YAML
 added: v9.6.0

diff --git a/lib/async_hooks.js b/lib/async_hooks.js
@@ -2,13 +2,15 @@
 
 const {
   NumberIsSafeInteger,
+  ObjectDefineProperties,
   ReflectApply,
   Symbol,
 } = primordials;
 
 const {
   ERR_ASYNC_CALLBACK,
   ERR_ASYNC_TYPE,
+  ERR_INVALID_ARG_TYPE,
   ERR_INVALID_ASYNC_ID
 } = require('internal/errors').codes;
 const { validateString } = require('internal/validators');
@@ -213,7 +215,20 @@ class AsyncResource {
   }
 
   bind(fn) {
-    return this.runInAsyncScope.bind(this, fn);
+    if (typeof fn !== 'function')
+      throw new ERR_INVALID_ARG_TYPE('fn', 'Function', fn);
+    const ret = this.runInAsyncScope.bind(this, fn);
+    ObjectDefineProperties(ret, {
+      'length': {
+        enumerable: true,
+        value: fn.length,
+      },
+      'asyncResource': {
+        enumerable: true,
+        value: this,
+      }
+    });
+    return ret;
   }
 
   static bind(fn, type) {

diff --git a/test/parallel/test-asyncresource-bind.js b/test/parallel/test-asyncresource-bind.js
@@ -15,10 +15,19 @@ setImmediate(() => {
 
 const asyncResource = new AsyncResource('test');
 
-const fn2 = asyncResource.bind(() => {
+[1, false, '', {}, []].forEach((i) => {
+  assert.throws(() => asyncResource.bind(i), {
+    code: 'ERR_INVALID_ARG_TYPE'
+  });
+});
+
+const fn2 = asyncResource.bind((a, b) => {
   return executionAsyncId();
 });
 
+assert.strictEqual(fn2.asyncResource, asyncResource);
+assert.strictEqual(fn2.length, 2);
+
 setImmediate(() => {
   const asyncId = executionAsyncId();
   assert.strictEqual(asyncResource.asyncId(), fn2());