feat: initial commit

.babelrc.js

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+module.exports = {
+  presets: [
+    [
+      '@babel/preset-env',
+      {
+        modules: process.env.NODE_ENV === 'test' && 'commonjs',
+        targets: {node: '6'},
+      },
+    ],
+    '@babel/preset-flow',
+  ],
+};

.circleci/config.yml

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+jobs:
+
+  lint:
+    docker:
+      - image: circleci/node:8
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+          - v1-dependencies-{{ checksum "package.json" }}
+          - v1-dependencies-
+      - run: yarn install
+      - save_cache:
+          paths:
+            - node_modules
+          key: v1-dependencies-{{ checksum "package.json" }}
+      - run: yarn lint
+    working_directory: ~/repo
+
+  release:
+    docker:
+      - image: circleci/node:8
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+          - v1-dependencies-{{ checksum "package.json" }}
+          - v1-dependencies-
+      - run: yarn install
+      - save_cache:
+          paths:
+            - node_modules
+          key: v1-dependencies-{{ checksum "package.json" }}
+      - run: yarn build
+      - run: npx semantic-release
+
+  test:
+    docker:
+      - image: circleci/node:8
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+          - v1-dependencies-{{ checksum "package.json" }}
+          - v1-dependencies-
+      - run: yarn install
+      - save_cache:
+          paths:
+            - node_modules
+          key: v1-dependencies-{{ checksum "package.json" }}
+      - run: yarn test:src
+    working_directory: ~/repo
+
+  test-dist:
+    docker:
+      - image: circleci/node:8
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+          - v1-dependencies-{{ checksum "package.json" }}
+          - v1-dependencies-
+      - run: yarn install
+      - save_cache:
+          paths:
+            - node_modules
+          key: v1-dependencies-{{ checksum "package.json" }}
+      - run: yarn build
+      - run: yarn test:dist
+    working_directory: ~/repo
+
+version: 2
+
+workflows:
+  test_and_release:
+    jobs:
+      - lint
+      - test
+      - test-dist
+      - release:
+          filters:
+            branches:
+              only: master
+          requires:
+            - lint
+            - test
+            - test-dist
+  version: 2

.commitlintrc.yml

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+extends:
+  - '@commitlint/config-conventional'

.eslintignore

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+coverage/*
+dist/*
+flow-typed/*
+node_modules/*

.eslintrc.yml

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+env:
+  jest: true
+
+extends:
+  - airbnb-base
+  - plugin:flowtype/recommended
+  - prettier
+  - prettier/flowtype
+
+parser: babel-eslint
+
+plugins:
+  - flowtype
+
+rules:
+  no-restricted-syntax:
+    - error
+    - message: for..in loops iterate over the entire prototype chain, which is virtually
+        never what you want. Use Object.{keys,values,entries}, and iterate over the resulting
+        array.
+      selector: ForInStatement
+    - message: Labels are a form of GOTO; using them makes code confusing and hard to
+        maintain and understand.
+      selector: LabeledStatement
+    - message: "`with` is disallowed in strict mode because it makes code impossible to
+        predict and optimize."
+      selector: WithStatement

.flowconfig

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+[ignore]
+
+[include]
+
+[libs]
+
+[lints]
+
+[options]
+
+[strict]

.gitignore

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+coverage
+dist
+lib
+node_modules
+yarn.lock
+*.log*

.huskyrc.yml

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+hooks:
+  commit-msg: commitlint -e $HUSKY_GIT_PARAMS
+  pre-commit: flow && lint-staged && yarn docs

.lintstagedrc.yml

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+linters:
+ "*.{json,md}": ["prettier --write", "git add"]
+ "*.{js}": ["prettier --write", "eslint --fix", "git add", "jest --config ./scripts/jest/config.source.js --bail --findRelatedTests"]

.prettierignore

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+package.json

.prettierrc.yml

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+bracketSpacing: false
+singleQuote: true
+trailingComma: all

LICENSE

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+MIT License
+
+Copyright (c) Matthew Fernando Garcia <wtgtybhertgeghgtwtg@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+# buffer-async-iterator
+
+> Buffer an AsyncIterator before iteration.
+
+Create an AsyncIterator over the values of an AsyncIterator, eagerly iterated.
+
+## Install
+
+    $ yarn buffer-async-iterator
+
+## API
+
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+#### Table of Contents
+
+- [bufferAsyncIterator](#bufferasynciterator)
+
+### bufferAsyncIterator
+
+Create an AsyncIterator from `iterable`, with the values eagerly buffered.
+
+**Parameters**
+
+- `iterable` **(AsyncIterable&lt;Value> | Iterable&lt;Value>)** The iterable whose values will be buffered.
+- `write` **Write** A function that takes `iterable` and `buffer` and returns a Promise. `buffer` will not be iterated through until it resolves. (optional, default `defaultWrite`)
+- `buffer` **(AsyncIterable&lt;Value> | Iterable&lt;Value>)** An iterable representing the data being buffered. (optional, default `[]`)
+
+**Examples**
+
+```javascript
+import bufferAsyncIterator from 'bufferAsyncIterator';
+import got from 'got';
+
+async function* getWebsites(sites) {
+  for (const site of sites) {
+    yield await got(site);
+  }
+}
+
+// Immediate start running the generator.
+const websiteIterator = bufferAsyncIterator(getWebsites(['google.com', 'bing.com', 'is-yahoo-still-around.com']));
+
+for await (const site of websiteIterator) {
+  // Iteration begins only after the original generator has finished.
+}
+```
+
+## License
+
+MIT © Matthew Fernando Garcia

__tests__/bufferAsyncIterator.test.js

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+// @flow
+/* eslint-disable require-yield */
+import bufferAsyncIterator from '../src';
+
+async function* sample(done = () => {}) {
+  yield 1;
+  yield 2;
+  yield 3;
+  done();
+}
+
+function* syncSample(done = () => {}) {
+  yield 1;
+  yield 2;
+  yield 3;
+  done();
+}
+
+describe('bufferAsyncIterator', () => {
+  describe('invariants', () => {
+    it('throws if "iterable" is neither an AsyncIterable nor an Iterable.', () => {
+      // $FlowFixMe
+      expect(() => bufferAsyncIterator(3)).toThrow(
+        '"iterable" must be an AsyncIterable or Iterable.',
+      );
+    });
+
+    it('throws if "write" is neither a function nor undefined.', () => {
+      expect(() =>
+        // $FlowFixMe
+        bufferAsyncIterator([], 'Neither a function nor undefined.'),
+      ).toThrow('"write" must be a function or undefined.');
+    });
+
+    it('throws if "buffer" is neither an AsyncIterable, an Iterable, or undefined.', () => {
+      // $FlowFixMe
+      expect(() => bufferAsyncIterator([], undefined, 3)).toThrow(
+        '"buffer" must be an AsyncIterable, an Iterable, or undefined.',
+      );
+    });
+
+    it('throws if "write" is undefined and "buffer.push" is not a function.', () => {
+      expect(() => bufferAsyncIterator([], undefined, new Map())).toThrow(
+        'When using the default "write" function, "buffer.push" must be a function.',
+      );
+    });
+  });
+
+  describe('default buffering', () => {
+    it('buffers an AsyncIterable.', done => {
+      bufferAsyncIterator(sample(done));
+    });
+
+    it('buffers an Iterable.', done => {
+      bufferAsyncIterator(syncSample(done));
+    });
+
+    it('passes through all values.', async () => {
+      const values = [1, 2, 3];
+      let index = 0;
+      for await (const value of bufferAsyncIterator(values)) {
+        expect(values[index]).toEqual(value);
+        index += 1;
+      }
+    });
+
+    it('rejects if "iterable" rejects.', async () => {
+      const message = 'Iterable error.';
+
+      async function* rejectSample() {
+        throw new Error(message);
+      }
+
+      await expect(bufferAsyncIterator(rejectSample()).next()).rejects.toThrow(
+        message,
+      );
+    });
+
+    it('rejects if "iterable" throws.', async () => {
+      const message = 'Iterable error.';
+
+      function* rejectSample() {
+        throw new Error(message);
+      }
+
+      await expect(bufferAsyncIterator(rejectSample()).next()).rejects.toThrow(
+        message,
+      );
+    });
+  });
+
+  describe('with a "write" function.', () => {
+    it('does not iterate through "buffer" until "write" resolves.', async () => {
+      let hasResolved = false;
+      async function write() {
+        hasResolved = true;
+      }
+      await bufferAsyncIterator(sample(), write).next();
+      expect(hasResolved).toBe(true);
+    });
+
+    it('rejects if "write" rejects.', async () => {
+      const message = 'Write error.';
+
+      async function write() {
+        throw new Error(message);
+      }
+      await expect(bufferAsyncIterator(sample(), write).next()).rejects.toThrow(
+        message,
+      );
+    });
+
+    it('yields the values "write" adds to "buffer".', async () => {
+      async function write(iterable, buffer) {
+        for (const value of iterable) {
+          buffer.push(value * 3);
+        }
+      }
+
+      const values = [1, 2, 3];
+      let index = 0;
+
+      for await (const value of bufferAsyncIterator(values, write)) {
+        expect(value).toBe(values[index] * 3);
+        index += 1;
+      }
+    });
+  });
+
+  describe('with a "buffer".', () => {
+    it('rejects if "buffer" rejects.', async () => {
+      const message = 'Buffer error.';
+
+      async function* buffer() {
+        throw new Error(message);
+      }
+
+      await expect(
+        bufferAsyncIterator(sample(), () => {}, buffer()).next(),
+      ).rejects.toThrow(message);
+    });
+  });
+});