feat: engines and files rules

Author: shellscape

README.md

@@ -48,6 +48,38 @@ $ npx prettier --write package.json
 
 This plugin enforces its own set of opinionated rules:
 
+### Engines
+
+Keys in `engines` are ordered alphabetically.
+
+#### Options
+
+`enginesNode`<br>
+Type: `string`
+
+Asserts an `engines.node` property value. e.g. `{ enginesNode: '>= 10.0.0' }`. If this option is set and no `node` key exists in `engines`, it will be created.
+
+`enginesNpm`<br>
+Type: `string`
+
+Asserts an `engines.npm` property value. e.g. `{ enginesNpm: '>= 10.0.0' }`. If this option is set and no `npm` key exists in `engines`, it will be created.
+
+### Files
+
+Keys in `files` are ordered alphabetically. Additionally, `LICENSE` and `README.md` are added to `files` if they are missing. This plugin prefers implicit declaration of those files, even though they are included in a package automatically by `npm`.
+
+#### Options
+
+`filesLicense`<br>
+Type: `boolean`
+
+To prevent `LICENSE` from being added to `files`, set this option to `false`.
+
+`filesReadme`<br>
+Type: `boolean`
+
+To prevent `README.md` from being added to `files`, set this option to `false`.
+
 ### Scripts
 
 Keys in `scripts` are ordered alphabetically. Use prefixes wisely to properly order child scripts. e.g. `lint`, `lint:ts`.
@@ -102,8 +134,6 @@ Unknown keys, or keys not part of the list above, will be alphabetically sorted
 Forthcoming rules include:
 
 - [ ] Author format
-- [ ] Engines format
-- [ ] Files order and content
 - [ ] Repository format
 
 ## Meta

lib/index.js

@@ -10,22 +10,28 @@
 */
 const { parsers } = require('prettier/parser-babylon');
 
-const { scripts } = require('./scripts');
-const { sort } = require('./sort');
+const { engines } = require('./rules/engines');
+const { files } = require('./rules/files');
+const { options: pluginOptions } = require('./options');
+const { scripts } = require('./rules/scripts');
+const { sort } = require('./rules/sort');
 
 const { 'json-stringify': parser } = parsers;
 const { parse } = parser;
 const rePkg = /package\.json$/;
 
-const format = (properties) => {
+const format = (properties, options) => {
   let props = sort(properties);
+  props = engines(props, options);
+  props = files(props, options);
   props = scripts(props);
 
   return props;
 };
 
 module.exports = {
   name: 'prettier-plugin-package',
+  options: pluginOptions,
   parsers: {
     'json-stringify': {
       ...parser,
@@ -36,7 +42,7 @@ module.exports = {
 
         if (rePkg.test(filepath)) {
           const { properties } = ast;
-          ast.properties = format(properties);
+          ast.properties = format(properties, options);
         }
 
         return ast;

lib/options.js

@@ -0,0 +1,46 @@
+/*
+  Copyright © 2019 Andrew Powell
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of this Source Code Form.
+*/
+const options = {
+  enginesNode: {
+    type: 'path',
+    category: 'Prettier Package',
+    default: '',
+    description: 'Asserts an `engines.node` property value for package.json.'
+  },
+  enginesNpm: {
+    type: 'path',
+    category: 'Prettier Package',
+    default: '',
+    description: 'Asserts an `engines.npm` property value for package.json.'
+  },
+  filesLicense: {
+    type: 'boolean',
+    category: 'Prettier Package',
+    default: true,
+    description:
+      'If true, asserts `LICENSE` as an entry in the `files` property value for package.json.'
+  },
+  filesReadme: {
+    type: 'boolean',
+    category: 'Prettier Package',
+    default: true,
+    description:
+      'If true, asserts `README.md` as an entry in the `files` property value for package.json.'
+  },
+  repository: {
+    type: 'path',
+    category: 'Prettier Package',
+    default: '',
+    description: 'Enforce a `repository` property value for package.json.'
+  }
+};
+
+module.exports = { options };

lib/rules/engines.js

@@ -0,0 +1,56 @@
+/*
+  Copyright © 2019 Andrew Powell
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of this Source Code Form.
+*/
+const process = (props, { enginesNode, enginesNpm }) => {
+  const enginesIndex = props.findIndex((prop) => prop.key.value === 'engines');
+
+  if (enginesIndex >= 0) {
+    const [engines] = props.splice(enginesIndex, 1);
+    const { properties } = engines.value;
+
+    properties.sort((a, b) => (a.key.value > b.key.value ? 1 : a.key.value < b.key.value ? -1 : 0));
+
+    if (enginesNode) {
+      const nodeIndex = properties.findIndex((prop) => prop.key.value === 'node');
+
+      if (nodeIndex >= 0) {
+        properties[nodeIndex].value.value = enginesNode;
+      } else {
+        properties.push({
+          type: 'ObjectProperty',
+          key: { type: 'StringLiteral', value: 'node' },
+          value: { type: 'StringLiteral', value: enginesNode }
+        });
+      }
+    }
+
+    if (enginesNpm) {
+      const npmIndex = properties.findIndex((prop) => prop.key.value === 'npm');
+
+      if (npmIndex >= 0) {
+        properties[npmIndex].value.value = enginesNpm;
+      } else {
+        properties.push({
+          type: 'ObjectProperty',
+          key: { type: 'StringLiteral', value: 'npm' },
+          value: { type: 'StringLiteral', value: enginesNpm }
+        });
+      }
+    }
+
+    engines.value.properties = properties;
+
+    props.splice(enginesIndex, 0, engines);
+  }
+
+  return props;
+};
+
+module.exports = { engines: process };

lib/rules/files.js

@@ -0,0 +1,42 @@
+/*
+  Copyright © 2019 Andrew Powell
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of this Source Code Form.
+*/
+const files = (props, { filesReadme, filesLicense }) => {
+  const filesIndex = props.findIndex((prop) => prop.key.value === 'files');
+
+  if (filesIndex >= 0) {
+    const [filesNode] = props.splice(filesIndex, 1);
+
+    let { elements } = filesNode.value;
+
+    elements = elements
+      .filter((node) => {
+        const value = node.value.toLowerCase();
+        return value !== 'license' && value !== 'readme.md';
+      })
+      .sort((a, b) => (a.value > b.value ? 1 : a.value < b.value ? -1 : 0));
+
+    if (filesLicense) {
+      elements.push({ type: 'StringLiteral', value: 'LICENSE' });
+    }
+
+    if (filesReadme) {
+      elements.push({ type: 'StringLiteral', value: 'README.md' });
+    }
+
+    filesNode.value.elements = elements;
+
+    props.splice(filesIndex, 0, filesNode);
+  }
+
+  return props;
+};
+
+module.exports = { files };

lib/scripts.js renamed to lib/rules/scripts.js

@@ -11,7 +11,7 @@
 const sort = (props) => {
   const scriptsIndex = props.findIndex((prop) => prop.key.value === 'scripts');
 
-  if (scriptsIndex) {
+  if (scriptsIndex >= 0) {
     const scripts = props[scriptsIndex];
     scripts.value.properties.sort((a, b) =>
       a.key.value > b.key.value ? 1 : a.key.value < b.key.value ? -1 : 0

lib/sort.js renamed to lib/rules/sort.js

@@ -0,0 +1,79 @@
+const test = require('ava');
+const prettier = require('prettier');
+
+test('default', (t) => {
+  const options = {
+    filepath: 'package.json',
+    parser: 'json-stringify',
+    plugins: ['.']
+  };
+  const fixture = {
+    engines: {
+      npm: 'joker',
+      node: 'batman'
+    }
+  };
+
+  const input = JSON.stringify(fixture, null, 2);
+  const output = prettier.format(input, options);
+
+  t.snapshot(output);
+});
+
+test('enginesNode', (t) => {
+  const options = {
+    enginesNode: '>= batcave',
+    filepath: 'package.json',
+    parser: 'json-stringify',
+    plugins: ['.']
+  };
+  const fixture = {
+    engines: {
+      npm: 'joker',
+      node: 'batman'
+    }
+  };
+
+  const input = JSON.stringify(fixture, null, 2);
+  const output = prettier.format(input, options);
+
+  t.snapshot(output);
+});
+
+test('enginesNpm', (t) => {
+  const options = {
+    enginesNpm: '>= harley',
+    filepath: 'package.json',
+    parser: 'json-stringify',
+    plugins: ['.']
+  };
+  const fixture = {
+    engines: {
+      npm: 'joker',
+      node: 'batman'
+    }
+  };
+
+  const input = JSON.stringify(fixture, null, 2);
+  const output = prettier.format(input, options);
+
+  t.snapshot(output);
+});
+
+test('missing', (t) => {
+  const options = {
+    enginesNode: '>= batcave',
+    enginesNpm: '>= harley',
+    filepath: 'package.json',
+    parser: 'json-stringify',
+    plugins: ['.']
+  };
+  const fixture = {
+    engines: {}
+  };
+
+  const input = JSON.stringify(fixture, null, 2);
+  const output = prettier.format(input, options);
+
+  t.snapshot(output);
+});

test/engines.js

@@ -0,0 +1,52 @@
+const test = require('ava');
+const prettier = require('prettier');
+
+test('default', (t) => {
+  const options = {
+    filepath: 'package.json',
+    parser: 'json-stringify',
+    plugins: ['.']
+  };
+  const fixture = {
+    files: ['lib/']
+  };
+
+  const input = JSON.stringify(fixture, null, 2);
+  const output = prettier.format(input, options);
+
+  t.snapshot(output);
+});
+
+test('filesLicense', (t) => {
+  const options = {
+    filepath: 'package.json',
+    filesLicense: false,
+    parser: 'json-stringify',
+    plugins: ['.']
+  };
+  const fixture = {
+    files: ['lib/']
+  };
+
+  const input = JSON.stringify(fixture, null, 2);
+  const output = prettier.format(input, options);
+
+  t.snapshot(output);
+});
+
+test('filesReadme', (t) => {
+  const options = {
+    filepath: 'package.json',
+    filesReadme: false,
+    parser: 'json-stringify',
+    plugins: ['.']
+  };
+  const fixture = {
+    files: ['lib/']
+  };
+
+  const input = JSON.stringify(fixture, null, 2);
+  const output = prettier.format(input, options);
+
+  t.snapshot(output);
+});

test/files.js

@@ -25,9 +25,10 @@
     "lint-staged": "lint-staged"
   },
   "files": [
-    "lib/",
     "README.md",
-    "LICENSE"
+    "lib/",
+    "LICENSE",
+    "index.js"
   ],
   "keywords": [
     "package",