feature: @putout/plugin-generators: add

README.md

@@ -2170,6 +2170,7 @@ It has a lot plugins divided by groups:
 | [`@putout/plugin-eslint`](/packages/plugin-eslint#readme) | [![npm](https://img.shields.io/npm/v/@putout/plugin-eslint.svg?maxAge=86400)](https://www.npmjs.com/package/@putout/plugin-eslint) |
 | [`@putout/plugin-package-json`](/packages/plugin-package-json#readme) | [![npm](https://img.shields.io/npm/v/@putout/plugin-package-json.svg?maxAge=86400)](https://www.npmjs.com/package/@putout/plugin-package-json) |
 | [`@putout/plugin-promises`](/packages/plugin-promises#readme) | [![npm](https://img.shields.io/npm/v/@putout/plugin-promises.svg?maxAge=86400)](https://www.npmjs.com/package/@putout/plugin-promises) |
+| [`@putout/plugin-generators`](/packages/plugin-generators#readme) | [![npm](https://img.shields.io/npm/v/@putout/plugin-generators.svg?maxAge=86400)](https://www.npmjs.com/package/@putout/plugin-generators) |
 | [`@putout/plugin-gitignore`](/packages/plugin-gitignore#readme) | [![npm](https://img.shields.io/npm/v/@putout/plugin-gitignore.svg?maxAge=86400)](https://www.npmjs.com/package/@putout/plugin-gitignore) |
 | [`@putout/plugin-npmignore`](/packages/plugin-npmignore#readme) | [![npm](https://img.shields.io/npm/v/@putout/plugin-npmignore.svg?maxAge=86400)](https://www.npmjs.com/package/@putout/plugin-npmignore) |
 | [`@putout/plugin-coverage`](/packages/plugin-coverage#readme) | [![npm](https://img.shields.io/npm/v/@putout/plugin-coverage.svg?maxAge=86400)](https://www.npmjs.com/package/@putout/plugin-coverage) |

packages/plugin-generators/.eslintrc.json

@@ -0,0 +1,10 @@
+{
+    "extends": [
+        "plugin:n/recommended",
+        "plugin:putout/recommended"
+    ],
+    "plugins": [
+        "n",
+        "putout"
+    ]
+}

packages/plugin-generators/.gitignore

@@ -0,0 +1,6 @@
+node_modules
+*.swp
+yarn-error.log
+
+coverage
+.idea

packages/plugin-generators/.madrun.mjs

@@ -0,0 +1,12 @@
+import {run} from 'madrun';
+
+export default {
+    'test': () => `tape 'test/*.js' 'lib/**/*.spec.js'`,
+    'watch:test': async () => `nodemon -w lib -w test -x ${await run('test')}`,
+    'lint': () => `putout .`,
+    'fresh:lint': () => run('lint', '--fresh'),
+    'lint:fresh': () => run('lint', '--fresh'),
+    'fix:lint': () => run('lint', '--fix'),
+    'coverage': async () => `c8 ${await run('test')}`,
+    'report': () => 'c8 report --reporter=lcov',
+};

packages/plugin-generators/.npmignore

@@ -0,0 +1,9 @@
+.*
+test
+yarn-error.log
+*.spec.js
+fixture
+
+
+coverage
+*.config.*

packages/plugin-generators/.nycrc.json

@@ -0,0 +1,15 @@
+{
+    "check-coverage": true,
+    "all": true,
+    "exclude": [
+        "**/*.spec.*",
+        "**/fixture",
+        "test",
+        ".*.*",
+        "**/*.config.*"
+    ],
+    "branches": 100,
+    "lines": 100,
+    "functions": 100,
+    "statements": 100
+}

packages/plugin-generators/.putout.json

@@ -0,0 +1,8 @@
+{
+    "printer": "putout",
+    "match": {
+        "*.md": {
+            "generators": "off"
+        }
+    }
+}

packages/plugin-generators/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) coderaiser
+
+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.

packages/plugin-generators/README.md

@@ -0,0 +1,85 @@
+# @putout/plugin-generators [![NPM version][NPMIMGURL]][NPMURL]
+
+[NPMIMGURL]: https://img.shields.io/npm/v/@putout/plugin-generators.svg?style=flat&longCache=true
+[NPMURL]: https://npmjs.org/package/@putout/plugin-generators"npm"
+
+> The `function*` declaration creates a binding of a new generator function to a given name. A generator function can be exited and later re-entered, with its context (variable bindings) saved across re-entrances.
+>
+> (c) [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)
+
+🐊[**Putout**](https://github.com/coderaiser/putout) plugin improves `Generator`-related code.
+
+## Install
+
+```
+npm i @putout/plugin-generators -D
+```
+
+## Rules
+
+- ✅ [add-missing-star](#add-missing-star);
+- ✅ [convert-multiple-to-generator](#convert-multiply-to-generator);
+
+## Config
+
+```json
+{
+    "rules": {
+        "generators/add-missing-star": "on",
+        "generators/convert-multiple-to-generator": "on"
+    }
+}
+```
+
+## add-missing-star
+
+> The `function*` declaration creates a binding of a new generator function to a given name.
+>
+> (c) [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*)
+
+### ❌ Example of incorrect code
+
+```js
+function hello() {
+    yield;
+    'world';
+}
+
+function func2() {
+    yield * func1();
+}
+```
+
+### ✅ Example of correct code
+
+```js
+function* hello() {
+    yield 'world';
+}
+
+function* func2() {
+    yield* func1();
+}
+```
+
+## convert-multiply-to-generator
+
+Checkout in 🐊[**Putout Editor**](https://putout.cloudcmd.io/#/gist/1c5326b470677a2ab253963fe39971f2/860b7eafb0bdd33ec007e709e7825c47bbc38940).
+
+### ❌ Example of incorrect code
+
+```js
+const a = 5 * function hello() {};
+```
+
+### ✅ Example of correct code
+
+```js
+const a = 5;
+
+function* hello() {}
+```
+
+## License
+
+MIT

packages/plugin-generators/lib/add-missing-star/fixture/add-missing-star-fix.js

@@ -0,0 +1,3 @@
+function* x() {
+    yield m;
+}

packages/plugin-generators/lib/add-missing-star/fixture/add-missing-star.js

@@ -0,0 +1,3 @@
+function x () {
+    yield m;
+}

packages/plugin-generators/lib/add-missing-star/fixture/member.js

@@ -0,0 +1 @@
+const ast = parse(fixture.yield);

packages/plugin-generators/lib/add-missing-star/fixture/yield-star-fix.js

@@ -0,0 +1,3 @@
+function* func2() {
+    yield* func1();
+}

packages/plugin-generators/lib/add-missing-star/fixture/yield-star.js

@@ -0,0 +1,3 @@
+function func2() {
+  yield* func1();
+}

packages/plugin-generators/lib/add-missing-star/index.js

@@ -0,0 +1,47 @@
+'use strict';
+
+const {types, operator} = require('putout');
+const {remove, replaceWith} = operator;
+const {YieldExpression} = types;
+
+const DELEGATE = true;
+
+module.exports.report = () => `Add missing '*' in generator function`;
+
+module.exports.fix = (path) => {
+    const fnPath = path.getFunctionParent();
+
+    fnPath.node.generator = true;
+
+    if (path.parentPath.isExpressionStatement()) {
+        const next = path.parentPath.getNextSibling();
+        const {expression} = next.node;
+
+        replaceWith(path, YieldExpression(expression));
+        remove(next);
+
+        return;
+    }
+
+    const {parentPath} = path;
+    const {right} = parentPath.node;
+
+    replaceWith(parentPath, YieldExpression(right, DELEGATE));
+};
+
+module.exports.traverse = ({push}) => ({
+    Identifier(path) {
+        if (path.node.name !== 'yield')
+            return;
+
+        if (path.parentPath.isBinaryExpression({operator: '*'})) {
+            push(path);
+            return;
+        }
+
+        if (!path.parentPath.isExpressionStatement())
+            return;
+
+        push(path);
+    },
+});

packages/plugin-generators/lib/add-missing-star/index.spec.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const {createTest} = require('@putout/test');
+const convert = require('.');
+
+const test = createTest(__dirname, {
+    printer: 'putout',
+    plugins: [
+        ['promises/add-missing-star', convert],
+    ],
+});
+
+test('plugin-add-missing-star: exports: report', (t) => {
+    t.report('add-missing-star', `Add missing '*' in generator function`);
+    t.end();
+});
+
+test('plugin-add-missing-star: no report: member', (t) => {
+    t.noReport('member');
+    t.end();
+});
+
+test('plugin-add-missing-star: transform', (t) => {
+    t.transform('add-missing-star');
+    t.end();
+});
+
+test('plugin-add-missing-star: transform: yield-star', (t) => {
+    t.transform('yield-star');
+    t.end();
+});

packages/plugin-generators/lib/convert-multiply-to-generator/fixture/convert-multiply-to-generator-fix.js

@@ -0,0 +1,10 @@
+const c = 1 * 2;
+1 + function() {};
+
+const a = 5;
+
+function* hello() {};
+let b = 5 * function() {};
+
+b = 5;
+function* world() {};

packages/plugin-generators/lib/convert-multiply-to-generator/fixture/convert-multiply-to-generator.js

@@ -0,0 +1,8 @@
+const c = 1 * 2;
+1 + function() {};
+
+const a = 5
+*function hello() {};
+
+let b = 5 * function() {};
+b = 5 * function world() {};

packages/plugin-generators/lib/convert-multiply-to-generator/index.js

@@ -0,0 +1,37 @@
+'use strict';
+
+const {types, operator} = require('putout');
+
+const {
+    insertAfter,
+    replaceWith,
+    getTemplateValues,
+} = operator;
+
+const {isStatement} = types;
+const MULTIPLY = '__a * __b';
+
+module.exports.report = () => `Use 'if condition' instead of 'ternary expression'`;
+
+module.exports.fix = (path) => {
+    const a = path.find(isStatement);
+    const {__a, __b} = getTemplateValues(path, MULTIPLY);
+
+    replaceWith(path, __a);
+    insertAfter(a, __b);
+    __b.generator = true;
+};
+
+module.exports.traverse = ({push}) => ({
+    [MULTIPLY]: (path) => {
+        const rightPath = path.get('right');
+
+        if (!rightPath.isFunctionExpression())
+            return;
+
+        if (!rightPath.node.id)
+            return;
+
+        push(path);
+    },
+});

packages/plugin-generators/lib/convert-multiply-to-generator/index.spec.js

@@ -0,0 +1,21 @@
+'use strict';
+
+const {createTest} = require('@putout/test');
+const plugin = require('.');
+
+const test = createTest(__dirname, {
+    printer: 'putout',
+    plugins: [
+        ['convert-multiply-to-generator', plugin],
+    ],
+});
+
+test('generators: convert-multiply-to-generator: report', (t) => {
+    t.report('convert-multiply-to-generator', `Use 'if condition' instead of 'ternary expression'`);
+    t.end();
+});
+
+test('generators: convert-multiply-to-generator: transform', (t) => {
+    t.transform('convert-multiply-to-generator');
+    t.end();
+});

packages/plugin-generators/lib/index.js

@@ -0,0 +1,9 @@
+'use strict';
+
+const addMissingStar = require('./add-missing-star');
+const convertMultiplyToGenerator = require('./convert-multiply-to-generator');
+
+module.exports.rules = {
+    'add-missing-star': addMissingStar,
+    'convert-multiply-to-generator': convertMultiplyToGenerator,
+};