combine-async-iterators - npm Package Compare versions

Comparing version 1.1.2 to 2.0.0

index.d.ts

@@ -1,4 +0,17 @@
-declare function combineAsyncIterators(...iterators: AsyncIterableIterator<any>[]): AsyncIterableIterator<any>;
+declare function combineAsyncIterators(
+    ...iterators: AsyncIterableIterator<any>[]
+): AsyncIterableIterator<any>;
 
+declare namespace combineAsyncIterators {
+    interface CombineOptions {
+        throwError?: boolean;
+        errorCallback?: (err: Error, index: number) => any;
+    }
+}
+
+declare function combineAsyncIterators(
+    options: combineAsyncIterators.CombineOptions,
+    ...iterators: AsyncIterableIterator<any>[]
+): AsyncIterableIterator<any>;
+
 export = combineAsyncIterators;
-

index.js

 "use strict";
 
-function getNextAsyncIteratorValue(asyncIterator, index) {
-    return asyncIterator.next().then((iterator) => {
-        return { index, iterator };
-    });
+function getNextAsyncIteratorFactory(options) {
+    return async(asyncIterator, index) => {
+        try {
+            const iterator = await asyncIterator.next();
+
+            return { index, iterator };
+        }
+        catch (err) {
+            if (options.errorCallback) {
+                options.errorCallback(err, index);
+            }
+            if (options.throwError !== false) {
+                return Promise.reject(err);
+            }
+
+            return { index, iterator: { done: true } };
+        }
+    };
 }
 
 async function* combineAsyncIterators(...iterators) {
+    let [options] = iterators;
+    if (typeof options.next === "function") {
+        options = Object.create(null);
+    }
+    else {
+        iterators.shift();
+    }
+
     // Return if iterators is empty (avoid infinite loop).
@@ -14,27 +36,21 @@ if (iterators.length === 0) {
     }
-    const promiseThatNeverResolve = new Promise(() => null);
+    const getNextAsyncIteratorValue = getNextAsyncIteratorFactory(options);
 
     try {
-        const asyncIteratorsValues = iterators.map(getNextAsyncIteratorValue);
-        let numberOfIteratorsAlive = iterators.length;
+        const asyncIteratorsValues = new Map(iterators.map((it, idx) => [idx, getNextAsyncIteratorValue(it, idx)]));
 
         do {
-            const { iterator, index } = await Promise.race(asyncIteratorsValues);
+            const { iterator, index } = await Promise.race(asyncIteratorsValues.values());
             if (iterator.done) {
-                numberOfIteratorsAlive--;
-                // We dont want Promise.race to resolve again on this index
-                // so we replace it with a Promise that will never resolve.
-                asyncIteratorsValues[index] = promiseThatNeverResolve;
+                asyncIteratorsValues.delete(index);
             }
             else {
                 yield iterator.value;
-                asyncIteratorsValues[index] = getNextAsyncIteratorValue(iterators[index], index);
+                asyncIteratorsValues.set(index, getNextAsyncIteratorValue(iterators[index], index));
             }
-        } while (numberOfIteratorsAlive > 0);
+        } while (asyncIteratorsValues.size > 0);
     }
-    catch (err) {
+    finally {
         // TODO: replace .all with .allSettled
         await Promise.all(iterators.map((it) => it.return()));
-
-        throw err;
     }
@@ -41,0 +57,0 @@ }

package.json

 {
-  "name": "combine-async-iterators",
-  "version": "1.1.2",
-  "description": "Combine Multiple Asynchronous Iterators in one (not a sequence)",
-  "main": "index.js",
-  "scripts": {
-    "test": "node test/test.js"
-  },
-  "engines": {
-    "node": ">=11"
-  },
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/fraxken/combine-async-iterators.git"
-  },
-  "files": [
-    "index.d.ts"
-  ],
-  "keywords": [
-    "async",
-    "asynchronous",
-    "iterator",
-    "iterators",
-    "iteration",
-    "iterable",
-    "combine",
-    "merge",
-    "build",
-    "construct",
-    "sequence"
-  ],
-  "author": "GENTILHOMME Thomas <[e-mail]>",
-  "license": "MIT",
-  "bugs": {
-    "url": "https://github.com/fraxken/combine-async-iterators/issues"
-  },
-  "homepage": "https://github.com/fraxken/combine-async-iterators#readme",
-  "devDependencies": {
-    "@slimio/eslint-config": "^3.0.3",
-    "@slimio/is": "^1.5.1",
-    "@types/node": "^12.6.8",
-    "japa": "^3.0.1"
-  }
+    "name": "combine-async-iterators",
+    "version": "2.0.0",
+    "description": "Combine Multiple Asynchronous Iterators in one (not a sequence)",
+    "main": "index.js",
+    "scripts": {
+        "test": "node test/test.js"
+    },
+    "engines": {
+        "node": ">=11"
+    },
+    "repository": {
+        "type": "git",
+        "url": "git+https://github.com/fraxken/combine-async-iterators.git"
+    },
+    "files": [
+        "index.d.ts"
+    ],
+    "keywords": [
+        "async",
+        "asynchronous",
+        "iterator",
+        "iterators",
+        "iteration",
+        "iterable",
+        "combine",
+        "merge",
+        "build",
+        "construct",
+        "sequence"
+    ],
+    "author": "GENTILHOMME Thomas <[e-mail]>",
+    "license": "MIT",
+    "bugs": {
+        "url": "https://github.com/fraxken/combine-async-iterators/issues"
+    },
+    "homepage": "https://github.com/fraxken/combine-async-iterators#readme",
+    "devDependencies": {
+        "@slimio/eslint-config": "^4.1.0",
+        "@slimio/is": "^1.5.1",
+        "@types/node": "^14.6.1",
+        "japa": "^3.1.1",
+        "sinon": "^9.0.2"
+    }
 }

README.md

@@ -10,2 +10,4 @@ # Combine-async-iterators
 
+> ⚠️ This package was mainly built to work with native Asynchronous Generators (Iterators).
+
 ## Requirements
@@ -47,6 +49,36 @@ - [Node.js](https://nodejs.org/en/) version 11 or higher
 
+**Since 2.0.0** it is also possible to recover errors through a callback. By default the method is stopped when an error is thrown (the `throwError` parameter allow to disable this behaviour).
+
+```js
+function errorCallback(err) {
+    console.error("got you:", err);
+}
+
+const iteratorOptions = { errorCallback, throwError: false };
+const asyncIterator = combineAsyncIterators(iteratorOptions, getValues("first"), getValues("second"));
+for await (const value of asyncIterator) {
+    console.log(value);
+}
+```
+
 ## API
 
 ```ts
-function combineAsyncIterators(...iterators: AsyncIterableIterator<any>[]): AsyncIterableIterator<any>
+declare function combineAsyncIterators(
+    ...iterators: AsyncIterableIterator<any>[]
+): AsyncIterableIterator<any>;
+
+declare namespace combineAsyncIterators {
+    interface CombineOptions {
+        throwError?: boolean;
+        errorCallback?: (err: Error, index: number) => any;
+    }
+}
+
+declare function combineAsyncIterators(
+    options: combineAsyncIterators.CombineOptions,
+    ...iterators: AsyncIterableIterator<any>[]
+): AsyncIterableIterator<any>;
+
+export = combineAsyncIterators;
 ```
@@ -53,0 +85,0 @@

No alert changes

Improved metrics

Total package byte prevSize

7267

increased by31.72%

Lines of code

64

increased by68.42%

Number of lines in readme file

87

increased by58.18%

Worsened metrics

Dev dependency count

5

increased by25%

No dependency changes