├── .editorconfig
├── .github
    └── workflows
    │   ├── bb.yml
    │   └── main.yml
├── .gitignore
├── .npmrc
├── .prettierignore
├── index.js
├── lib
    ├── a.js
    ├── an.js
    └── index.js
├── license
├── package.json
├── readme.md
├── test.js
└── tsconfig.json


/.editorconfig:
--------------------------------------------------------------------------------
 1 | root = true
 2 | 
 3 | [*]
 4 | indent_style = space
 5 | indent_size = 2
 6 | end_of_line = lf
 7 | charset = utf-8
 8 | trim_trailing_whitespace = true
 9 | insert_final_newline = true
10 | 


--------------------------------------------------------------------------------
/.github/workflows/bb.yml:
--------------------------------------------------------------------------------
 1 | name: bb
 2 | on:
 3 |   issues:
 4 |     types: [opened, reopened, edited, closed, labeled, unlabeled]
 5 |   pull_request_target:
 6 |     types: [opened, reopened, edited, closed, labeled, unlabeled]
 7 | jobs:
 8 |   main:
 9 |     runs-on: ubuntu-latest
10 |     steps:
11 |       - uses: unifiedjs/beep-boop-beta@main
12 |         with:
13 |           repo-token: ${{secrets.GITHUB_TOKEN}}
14 | 


--------------------------------------------------------------------------------
/.github/workflows/main.yml:
--------------------------------------------------------------------------------
 1 | name: main
 2 | on:
 3 |   - pull_request
 4 |   - push
 5 | jobs:
 6 |   main:
 7 |     name: ${{matrix.node}}
 8 |     runs-on: ubuntu-latest
 9 |     steps:
10 |       - uses: actions/checkout@v3
11 |       - uses: actions/setup-node@v3
12 |         with:
13 |           node-version: ${{matrix.node}}
14 |       - run: npm install
15 |       - run: npm test
16 |       - uses: codecov/codecov-action@v3
17 |     strategy:
18 |       matrix:
19 |         node:
20 |           - lts/gallium
21 |           - node
22 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
1 | coverage/
2 | node_modules/
3 | .DS_Store
4 | *.d.ts
5 | *.log
6 | yarn.lock
7 | 


--------------------------------------------------------------------------------
/.npmrc:
--------------------------------------------------------------------------------
1 | ignore-scripts=true
2 | package-lock=false
3 | 


--------------------------------------------------------------------------------
/.prettierignore:
--------------------------------------------------------------------------------
1 | coverage/
2 | *.md
3 | 


--------------------------------------------------------------------------------
/index.js:
--------------------------------------------------------------------------------
1 | export {default} from './lib/index.js'
2 | 


--------------------------------------------------------------------------------
/lib/a.js:
--------------------------------------------------------------------------------
  1 | /** @type {ReadonlyArray<string>} */
  2 | export const a = [
  3 |   // Please sort these entries.
  4 | 
  5 |   // Please *only* use casing if it adds something: `url` is fine, but it’s
  6 |   // `a UN meeting` and `an un-united germany`.
  7 |   'U',
  8 |   'UN',
  9 |   'eucalypt*',
 10 |   'eucha*',
 11 |   'euchr*',
 12 |   'euclid*',
 13 |   'eucrite',
 14 |   'eucryphia',
 15 |   'eugen*',
 16 |   'eukar*',
 17 |   'eulog*',
 18 |   'eunice',
 19 |   'eunuch',
 20 |   'euph*',
 21 |   'eura*',
 22 |   'eure*',
 23 |   'euro*',
 24 |   'eury*',
 25 |   'eutha*',
 26 |   'ewe',
 27 |   'ewer',
 28 |   'habitual',
 29 |   'hallucin*',
 30 |   'herb*',
 31 |   'heredit*',
 32 |   'hilarious*',
 33 |   'histor*',
 34 |   'horrend*',
 35 |   'horrif*',
 36 |   'hotel*',
 37 |   'ms',
 38 |   'once',
 39 |   'one',
 40 |   'one-*',
 41 |   'one/',
 42 |   'oneanother',
 43 |   'oneberry',
 44 |   'onefold*',
 45 |   'oneheart*',
 46 |   'oneness*',
 47 |   'oneself*',
 48 |   'onetime*',
 49 |   'oneway',
 50 |   'onewhere*',
 51 |   'oneyear',
 52 |   'ubiq*',
 53 |   'uefa',
 54 |   'ugandan',
 55 |   'uk',
 56 |   'ukase',
 57 |   'ukrain*',
 58 |   'ukulele',
 59 |   'ululated',
 60 |   'ululation',
 61 |   'unanim*',
 62 |   'unary',
 63 |   'unesco',
 64 |   'unhcr',
 65 |   'uniam*',
 66 |   'uniart*',
 67 |   'uniat*',
 68 |   'uniaur*',
 69 |   'uniax*',
 70 |   'unibas*',
 71 |   'unible',
 72 |   'unicycl*',
 73 |   'unidirect*',
 74 |   'unif*',
 75 |   'union*',
 76 |   'uniq*',
 77 |   'unist',
 78 |   'unit*',
 79 |   'univ*',
 80 |   'uran*',
 81 |   'urate',
 82 |   'uri*',
 83 |   'url',
 84 |   'urologist',
 85 |   'uruguay',
 86 |   'uruguayan',
 87 |   'uruguayans',
 88 |   'us',
 89 |   'usab*',
 90 |   'usage',
 91 |   'usb',
 92 |   'use*',
 93 |   'using',
 94 |   'usu*',
 95 |   'utah',
 96 |   'uten*',
 97 |   'uter*',
 98 |   'util*',
 99 |   'utop*',
100 |   'utrecht',
101 |   'uttoxeter',
102 |   'uvula',
103 |   'uvular',
104 |   'uyghur'
105 | ]
106 | 


--------------------------------------------------------------------------------
/lib/an.js:
--------------------------------------------------------------------------------
 1 | /** @type {ReadonlyArray<string>} */
 2 | export const an = [
 3 |   // Please sort these entries.
 4 |   // Please *only* use casing if it adds something: `url` is fine, but it’s
 5 |   // `a UN meeting` and `an un-united germany`.
 6 |   'IOU',
 7 |   'MA',
 8 |   'MS',
 9 |   'f',
10 |   'fbi',
11 |   'fda',
12 |   'fm',
13 |   'h',
14 |   'h1',
15 |   'h2',
16 |   'h3',
17 |   'h4',
18 |   'h5',
19 |   'h6',
20 |   'habitual',
21 |   'hallucin*',
22 |   'hauteur',
23 |   'hb',
24 |   'heir*',
25 |   'herb*',
26 |   'heredit*',
27 |   'hilarious*',
28 |   'histor*',
29 |   'hiv',
30 |   'homage',
31 |   'honest*',
32 |   'honor*',
33 |   'honour*',
34 |   'horrend*',
35 |   'horrif*',
36 |   'hotel*',
37 |   'hour*',
38 |   'html',
39 |   'l',
40 |   'lbw',
41 |   'lcd',
42 |   'm',
43 |   'mba',
44 |   'mdast',
45 |   'mpg',
46 |   'mph',
47 |   'mri',
48 |   'msc',
49 |   'mtv',
50 |   'n',
51 |   'nba',
52 |   'nbc',
53 |   'nfl',
54 |   'ngo',
55 |   'nhl',
56 |   'nlcst',
57 |   'npm',
58 |   'nvidia',
59 |   'r&d',
60 |   'r',
61 |   'raf',
62 |   's',
63 |   'sgml',
64 |   'sms',
65 |   'sos',
66 |   'spf',
67 |   'std',
68 |   'suv',
69 |   'x',
70 |   'x-ray',
71 |   'x-rays',
72 |   'xbox',
73 |   'xmas',
74 |   'xml',
75 |   'α'
76 | ]
77 | 


--------------------------------------------------------------------------------
/lib/index.js:
--------------------------------------------------------------------------------
  1 | /**
  2 |  * @typedef {import('nlcst').Root} Root
  3 |  * @typedef {import('nlcst').Sentence} Sentence
  4 |  * @typedef {import('nlcst').Word} Word
  5 |  *
  6 |  * @typedef {import('vfile').VFile} VFile
  7 |  */
  8 | 
  9 | /**
 10 |  * @typedef {'a' | 'a-or-an' | 'an'} Type
 11 |  *   Type.
 12 |  */
 13 | 
 14 | import {toString} from 'nlcst-to-string'
 15 | import numberToWords from 'number-to-words'
 16 | import {visit} from 'unist-util-visit'
 17 | import {a} from './a.js'
 18 | import {an} from './an.js'
 19 | 
 20 | const needsA = createCheck(a)
 21 | const needsAn = createCheck(an)
 22 | 
 23 | /**
 24 |  * Check `a` and `an`.
 25 |  *
 26 |  * @returns
 27 |  *   Transform.
 28 |  */
 29 | export default function retextIndefiniteArticle() {
 30 |   /**
 31 |    * Transform.
 32 |    *
 33 |    * @param {Root} tree
 34 |    *   Tree.
 35 |    * @param {VFile} file
 36 |    *   File.
 37 |    * @returns {undefined}
 38 |    *   Nothing.
 39 |    */
 40 |   return function (tree, file) {
 41 |     visit(tree, 'WordNode', function (node, index, parent) {
 42 |       const actual = toString(node)
 43 |       const normal = actual.toLowerCase()
 44 | 
 45 |       if (
 46 |         (normal !== 'a' && normal !== 'an') ||
 47 |         !parent ||
 48 |         index === undefined
 49 |       ) {
 50 |         return
 51 |       }
 52 | 
 53 |       const next = after(parent, index)
 54 | 
 55 |       if (!next) {
 56 |         return
 57 |       }
 58 | 
 59 |       const an = actual.length !== 1
 60 |       const following = toString(next)
 61 | 
 62 |       // Exit if `A` and this isn’t sentence-start: `Station A equals`
 63 |       if (normal !== actual && !an && !firstWord(parent, index)) {
 64 |         return
 65 |       }
 66 | 
 67 |       // Exit if `a` is used as a letter: `a and b`.
 68 |       if (normal === actual && !an && /^(and|nor|or)$/i.test(following)) {
 69 |         return
 70 |       }
 71 | 
 72 |       /** @type {string | undefined} */
 73 |       let expected = classify(following)
 74 | 
 75 |       if (!(expected === 'an' && !an) && !(expected === 'a' && an)) {
 76 |         return
 77 |       }
 78 | 
 79 |       if (normal !== actual) {
 80 |         expected = expected.charAt(0).toUpperCase() + expected.slice(1)
 81 |       }
 82 | 
 83 |       const message = file.message(
 84 |         'Unexpected article `' +
 85 |           actual +
 86 |           '` before `' +
 87 |           following +
 88 |           '`, expected `' +
 89 |           expected +
 90 |           '`',
 91 |         {
 92 |           ancestors: [parent, node],
 93 |           place: node.position,
 94 |           ruleId: 'retext-indefinite-article',
 95 |           source: 'retext-indefinite-article'
 96 |         }
 97 |       )
 98 | 
 99 |       message.actual = actual
100 |       message.expected = [expected]
101 |       message.url =
102 |         'https://github.com/retextjs/retext-indefinite-article#readme'
103 |     })
104 |   }
105 | }
106 | 
107 | /**
108 |  * Check if there’s no word before `index`.
109 |  *
110 |  * @param {Root | Sentence} parent
111 |  *   Node.
112 |  * @param {number} index
113 |  *   Index.
114 |  * @returns {boolean}
115 |  *   Whether there is no word before `index`.
116 |  */
117 | function firstWord(parent, index) {
118 |   const siblings = parent.children
119 | 
120 |   while (index--) {
121 |     if (siblings[index].type === 'WordNode') {
122 |       return false
123 |     }
124 |   }
125 | 
126 |   return true
127 | }
128 | 
129 | /**
130 |  * Get the next word.
131 |  *
132 |  * @param {Root | Sentence} parent
133 |  *   Node.
134 |  * @param {number} index
135 |  *   Index.
136 |  * @returns {Word | undefined}
137 |  *   Next word.
138 |  */
139 | function after(parent, index) {
140 |   const siblings = parent.children
141 |   let sibling = siblings[++index]
142 |   /** @type {Word | undefined} */
143 |   let other
144 | 
145 |   if (sibling && sibling.type === 'WhiteSpaceNode') {
146 |     sibling = siblings[++index]
147 | 
148 |     if (
149 |       sibling &&
150 |       sibling.type === 'PunctuationNode' &&
151 |       /^[“”‘’'"()[\]]$/.test(toString(sibling))
152 |     ) {
153 |       sibling = siblings[++index]
154 |     }
155 | 
156 |     if (sibling && sibling.type === 'WordNode') {
157 |       other = sibling
158 |     }
159 |   }
160 | 
161 |   return other
162 | }
163 | 
164 | /**
165 |  * Classify a word.
166 |  *
167 |  * @param {string} value
168 |  *   Word to classify.
169 |  * @returns {Type | undefined}
170 |  *   Type.
171 |  */
172 | function classify(value) {
173 |   const head = value
174 |     .replace(/^\d+/, function (value) {
175 |       return numberToWords.toWords(value) + ' '
176 |     })
177 |     .split(/['’ -]/, 1)[0]
178 |   const a = needsA(head)
179 |   const an = needsAn(head)
180 | 
181 |   return a && an
182 |     ? 'a-or-an'
183 |     : a
184 |     ? 'a'
185 |     : an
186 |     ? 'an'
187 |     : head.toLowerCase() === head
188 |     ? /[aeiou]/.test(head.charAt(0).toLowerCase())
189 |       ? 'an'
190 |       : 'a'
191 |     : undefined
192 | }
193 | 
194 | /**
195 |  * Create a test based on a list of phrases.
196 |  *
197 |  * @param {ReadonlyArray<string>} list
198 |  *   List of phrases.
199 |  * @returns
200 |  *   Check.
201 |  */
202 | function createCheck(list) {
203 |   /** @type {Set<RegExp>} */
204 |   const expressions = new Set()
205 |   /** @type {Set<string>} */
206 |   const sensitive = new Set()
207 |   /** @type {Set<string>} */
208 |   const insensitive = new Set()
209 |   let index = -1
210 | 
211 |   while (++index < list.length) {
212 |     const value = list[index]
213 | 
214 |     if (value.charAt(value.length - 1) === '*') {
215 |       // Regexes are insensitive now, once we need them this should check for
216 |       // `normal` as well.
217 |       expressions.add(new RegExp('^' + value.slice(0, -1), 'i'))
218 |     } else if (value === value.toLowerCase()) {
219 |       insensitive.add(value)
220 |     } else {
221 |       sensitive.add(value)
222 |     }
223 |   }
224 | 
225 |   return check
226 | 
227 |   /**
228 |    * Check.
229 |    *
230 |    * @param {string} value
231 |    *   Value to check.
232 |    * @returns {boolean}
233 |    *   Whether `value` is in `list`.
234 |    */
235 |   function check(value) {
236 |     if (sensitive.has(value) || insensitive.has(value.toLowerCase())) {
237 |       return true
238 |     }
239 | 
240 |     for (const expression of expressions) {
241 |       if (expression.test(value)) {
242 |         return true
243 |       }
244 |     }
245 | 
246 |     return false
247 |   }
248 | }
249 | 


--------------------------------------------------------------------------------
/license:
--------------------------------------------------------------------------------
 1 | (The MIT License)
 2 | 
 3 | Copyright (c) 2016 Titus Wormer <tituswormer@gmail.com>
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining
 6 | a copy of this software and associated documentation files (the
 7 | 'Software'), to deal in the Software without restriction, including
 8 | without limitation the rights to use, copy, modify, merge, publish,
 9 | distribute, sublicense, and/or sell copies of the Software, and to
10 | permit persons to whom the Software is furnished to do so, subject to
11 | the following conditions:
12 | 
13 | The above copyright notice and this permission notice shall be
14 | included in all copies or substantial portions of the Software.
15 | 
16 | THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
17 | EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 | MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
19 | IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
20 | CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
21 | TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
22 | SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 | 


--------------------------------------------------------------------------------
/package.json:
--------------------------------------------------------------------------------
  1 | {
  2 |   "name": "retext-indefinite-article",
  3 |   "version": "5.0.0",
  4 |   "description": "retext plugin to check if indefinite articles (`a`, `an`) are used correctly",
  5 |   "license": "MIT",
  6 |   "keywords": [
  7 |     "a",
  8 |     "an",
  9 |     "article",
 10 |     "articles",
 11 |     "indefinite",
 12 |     "plugin",
 13 |     "retext",
 14 |     "retext-plugin",
 15 |     "unified"
 16 |   ],
 17 |   "repository": "retextjs/retext-indefinite-article",
 18 |   "bugs": "https://github.com/retextjs/retext-indefinite-article/issues",
 19 |   "funding": {
 20 |     "type": "opencollective",
 21 |     "url": "https://opencollective.com/unified"
 22 |   },
 23 |   "author": "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)",
 24 |   "contributors": [
 25 |     "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)"
 26 |   ],
 27 |   "sideEffects": false,
 28 |   "type": "module",
 29 |   "exports": "./index.js",
 30 |   "files": [
 31 |     "lib/",
 32 |     "index.d.ts",
 33 |     "index.js"
 34 |   ],
 35 |   "dependencies": {
 36 |     "@types/nlcst": "^2.0.0",
 37 |     "nlcst-to-string": "^4.0.0",
 38 |     "number-to-words": "^1.0.0",
 39 |     "unist-util-visit": "^5.0.0",
 40 |     "vfile": "^6.0.0"
 41 |   },
 42 |   "devDependencies": {
 43 |     "@types/node": "^20.0.0",
 44 |     "@types/number-to-words": "^1.0.0",
 45 |     "c8": "^8.0.0",
 46 |     "chalk": "^5.0.0",
 47 |     "prettier": "^3.0.0",
 48 |     "remark-cli": "^11.0.0",
 49 |     "remark-preset-wooorm": "^9.0.0",
 50 |     "retext": "^9.0.0",
 51 |     "type-coverage": "^2.0.0",
 52 |     "typescript": "^5.0.0",
 53 |     "xo": "^0.56.0"
 54 |   },
 55 |   "scripts": {
 56 |     "build": "tsc --build --clean && tsc --build && type-coverage",
 57 |     "format": "remark . --frail --output --quiet && prettier . --log-level warn --write && xo --fix",
 58 |     "prepack": "npm run build && npm run format",
 59 |     "test": "npm run build && npm run format && npm run test-coverage",
 60 |     "test-api": "node --conditions development test.js",
 61 |     "test-coverage": "c8 --100 --check-coverage --reporter lcov npm run test-api"
 62 |   },
 63 |   "prettier": {
 64 |     "bracketSpacing": false,
 65 |     "singleQuote": true,
 66 |     "semi": false,
 67 |     "tabWidth": 2,
 68 |     "trailingComma": "none",
 69 |     "useTabs": false
 70 |   },
 71 |   "remarkConfig": {
 72 |     "plugins": [
 73 |       "remark-preset-wooorm"
 74 |     ]
 75 |   },
 76 |   "typeCoverage": {
 77 |     "atLeast": 100,
 78 |     "detail": true,
 79 |     "ignoreCatch": true,
 80 |     "strict": true
 81 |   },
 82 |   "xo": {
 83 |     "overrides": [
 84 |       {
 85 |         "files": [
 86 |           "test.js"
 87 |         ],
 88 |         "rules": {
 89 |           "no-await-in-loop": "off"
 90 |         }
 91 |       }
 92 |     ],
 93 |     "prettier": true,
 94 |     "rules": {
 95 |       "unicorn/prefer-at": "off",
 96 |       "unicorn/prefer-string-replace-all": "off"
 97 |     }
 98 |   }
 99 | }
100 | 


--------------------------------------------------------------------------------
/readme.md:
--------------------------------------------------------------------------------
  1 | # retext-indefinite-article
  2 | 
  3 | [![Build][build-badge]][build]
  4 | [![Coverage][coverage-badge]][coverage]
  5 | [![Downloads][downloads-badge]][downloads]
  6 | [![Size][size-badge]][size]
  7 | [![Sponsors][sponsors-badge]][collective]
  8 | [![Backers][backers-badge]][collective]
  9 | [![Chat][chat-badge]][chat]
 10 | 
 11 | **[retext][]** plugin to check `a` and `an`.
 12 | 
 13 | ## Contents
 14 | 
 15 | *   [What is this?](#what-is-this)
 16 | *   [When should I use this?](#when-should-i-use-this)
 17 | *   [Install](#install)
 18 | *   [Use](#use)
 19 | *   [API](#api)
 20 |     *   [`unified().use(retextIndefiniteArticle)`](#unifieduseretextindefinitearticle)
 21 | *   [Messages](#messages)
 22 | *   [Types](#types)
 23 | *   [Compatibility](#compatibility)
 24 | *   [Related](#related)
 25 | *   [Contribute](#contribute)
 26 | *   [License](#license)
 27 | 
 28 | ## What is this?
 29 | 
 30 | This package is a [unified][] ([retext][]) plugin to check indefinite articles
 31 | (`a` and `an`).
 32 | It’s more complex than checking vowels, as it has to do with sounds.
 33 | This package knows about how digits are pronounced as well.
 34 | 
 35 | ## When should I use this?
 36 | 
 37 | You can use this plugin when you’re dealing with content that might contain
 38 | grammar mistakes, and have authors that can fix that content.
 39 | 
 40 | ## Install
 41 | 
 42 | This package is [ESM only][esm].
 43 | In Node.js (version 16+), install with [npm][]:
 44 | 
 45 | ```sh
 46 | npm install retext-indefinite-article
 47 | ```
 48 | 
 49 | In Deno with [`esm.sh`][esmsh]:
 50 | 
 51 | ```js
 52 | import retextIndefiniteArticle from 'https://esm.sh/retext-indefinite-article@5'
 53 | ```
 54 | 
 55 | In browsers with [`esm.sh`][esmsh]:
 56 | 
 57 | ```html
 58 | <script type="module">
 59 |   import retextIndefiniteArticle from 'https://esm.sh/retext-indefinite-article@5?bundle'
 60 | </script>
 61 | ```
 62 | 
 63 | ## Use
 64 | 
 65 | Say our document `example.txt` contains:
 66 | 
 67 | ```txt
 68 | He should, a 8-year old boy, should have arrived a hour
 69 | ago on an European flight.
 70 | An historic event, or a historic event? Both are fine.
 71 | ```
 72 | 
 73 | …and our module `example.js` contains:
 74 | 
 75 | ```js
 76 | import retextEnglish from 'retext-english'
 77 | import retextIndefiniteArticle from 'retext-indefinite-article'
 78 | import retextStringify from 'retext-stringify'
 79 | import {read} from 'to-vfile'
 80 | import {unified} from 'unified'
 81 | import {reporter} from 'vfile-reporter'
 82 | 
 83 | const file = await unified()
 84 |   .use(retextEnglish)
 85 |   .use(retextIndefiniteArticle)
 86 |   .use(retextStringify)
 87 |   .process(await read('example.txt'))
 88 | 
 89 | console.error(reporter(file))
 90 | ```
 91 | 
 92 | …now running `node example.js` yields:
 93 | 
 94 | ```txt
 95 | example.txt
 96 | 1:12-1:13 warning Unexpected article `a` before `8-year`, expected `an`   retext-indefinite-article retext-indefinite-article
 97 | 1:50-1:51 warning Unexpected article `a` before `hour`, expected `an`     retext-indefinite-article retext-indefinite-article
 98 | 2:8-2:10  warning Unexpected article `an` before `European`, expected `a` retext-indefinite-article retext-indefinite-article
 99 | 
100 | ⚠ 3 warnings
101 | ```
102 | 
103 | ## API
104 | 
105 | This package exports no identifiers.
106 | The default export is
107 | [`retextIndefiniteArticle`][api-retext-indefinite-article].
108 | 
109 | ### `unified().use(retextIndefiniteArticle)`
110 | 
111 | Check `a` and `an`.
112 | 
113 | ###### Parameters
114 | 
115 | There are no parameters.
116 | 
117 | ###### Returns
118 | 
119 | Transform ([`Transformer`][unified-transformer]).
120 | 
121 | ## Messages
122 | 
123 | Each message is emitted as a [`VFileMessage`][vfile-message] on `file`, with
124 | `source` set to `'retext-indefinite-article'`, `ruleId` to
125 | `'retext-indefinite-article'`, `actual` to the unexpected word, and `expected`
126 | to suggestions.
127 | 
128 | ## Types
129 | 
130 | This package is fully typed with [TypeScript][].
131 | It exports no additional types.
132 | 
133 | ## Compatibility
134 | 
135 | Projects maintained by the unified collective are compatible with maintained
136 | versions of Node.js.
137 | 
138 | When we cut a new major release, we drop support for unmaintained versions of
139 | Node.
140 | This means we try to keep the current release line,
141 | `retext-indefinite-article@^5`, compatible with Node.js 16.
142 | 
143 | ## Related
144 | 
145 | *   [`retext-redundant-acronyms`](https://github.com/retextjs/retext-redundant-acronyms)
146 |     — check for redundant acronyms (`ATM machine`)
147 | *   [`retext-repeated-words`](https://github.com/retextjs/retext-repeated-words)
148 |     — check `for for` repeated words
149 | 
150 | ## Contribute
151 | 
152 | See [`contributing.md`][contributing] in [`retextjs/.github`][health] for ways
153 | to get started.
154 | See [`support.md`][support] for ways to get help.
155 | 
156 | This project has a [code of conduct][coc].
157 | By interacting with this repository, organization, or community you agree to
158 | abide by its terms.
159 | 
160 | ## License
161 | 
162 | [MIT][license] © [Titus Wormer][author]
163 | 
164 | <!-- Definitions -->
165 | 
166 | [build-badge]: https://github.com/retextjs/retext-indefinite-article/workflows/main/badge.svg
167 | 
168 | [build]: https://github.com/retextjs/retext-indefinite-article/actions
169 | 
170 | [coverage-badge]: https://img.shields.io/codecov/c/github/retextjs/retext-indefinite-article.svg
171 | 
172 | [coverage]: https://codecov.io/github/retextjs/retext-indefinite-article
173 | 
174 | [downloads-badge]: https://img.shields.io/npm/dm/retext-indefinite-article.svg
175 | 
176 | [downloads]: https://www.npmjs.com/package/retext-indefinite-article
177 | 
178 | [size-badge]: https://img.shields.io/bundlejs/size/retext-indefinite-article
179 | 
180 | [size]: https://bundlejs.com/?q=retext-indefinite-article
181 | 
182 | [sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg
183 | 
184 | [backers-badge]: https://opencollective.com/unified/backers/badge.svg
185 | 
186 | [collective]: https://opencollective.com/unified
187 | 
188 | [chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg
189 | 
190 | [chat]: https://github.com/retextjs/retext/discussions
191 | 
192 | [npm]: https://docs.npmjs.com/cli/install
193 | 
194 | [esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c
195 | 
196 | [esmsh]: https://esm.sh
197 | 
198 | [typescript]: https://www.typescriptlang.org
199 | 
200 | [health]: https://github.com/retextjs/.github
201 | 
202 | [contributing]: https://github.com/retextjs/.github/blob/main/contributing.md
203 | 
204 | [support]: https://github.com/retextjs/.github/blob/main/support.md
205 | 
206 | [coc]: https://github.com/retextjs/.github/blob/main/code-of-conduct.md
207 | 
208 | [license]: license
209 | 
210 | [author]: https://wooorm.com
211 | 
212 | [retext]: https://github.com/retextjs/retext
213 | 
214 | [unified]: https://github.com/unifiedjs/unified
215 | 
216 | [unified-transformer]: https://github.com/unifiedjs/unified#transformer
217 | 
218 | [vfile-message]: https://github.com/vfile/vfile-message
219 | 
220 | [api-retext-indefinite-article]: #unifieduseretextindefinitearticle
221 | 


--------------------------------------------------------------------------------
/test.js:
--------------------------------------------------------------------------------
  1 | import assert from 'node:assert/strict'
  2 | import test from 'node:test'
  3 | import chalk from 'chalk'
  4 | import {retext} from 'retext'
  5 | import retextIndefiniteArticle from 'retext-indefinite-article'
  6 | 
  7 | test('retextIndefiniteArticle', async function (t) {
  8 |   await t.test('should expose the public api', async function () {
  9 |     assert.deepEqual(
 10 |       Object.keys(await import('retext-indefinite-article')).sort(),
 11 |       ['default']
 12 |     )
 13 |   })
 14 | 
 15 |   await t.test('should catch indefinite articles', async function () {
 16 |     const file = await retext()
 17 |       .use(retextIndefiniteArticle)
 18 |       .process(
 19 |         [
 20 |           'He should have arrived a hour ago on an European flight.',
 21 |           'an historic event, or a historic event?'
 22 |         ].join('\n')
 23 |       )
 24 | 
 25 |     assert.deepEqual(file.messages.map(String), [
 26 |       '1:24-1:25: Unexpected article `a` before `hour`, expected `an`',
 27 |       '1:38-1:40: Unexpected article `an` before `European`, expected `a`'
 28 |     ])
 29 |   })
 30 | 
 31 |   const good = [
 32 |     // https://en.wikipedia.org/wiki/Article_(grammar)#Indefinite_article
 33 |     'She had a house so large that an elephant would get lost without a map',
 34 |     'a European',
 35 |     'a hallucination',
 36 |     'an hallucination',
 37 |     'a hilarious',
 38 |     'an hilarious',
 39 |     'a historic',
 40 |     'an historic',
 41 |     'a historical',
 42 |     'an historical',
 43 |     'a horrendous',
 44 |     'an horrendous',
 45 |     'a horrific',
 46 |     'an horrific',
 47 |     'a hotel',
 48 |     'an hotel',
 49 |     'a herb',
 50 |     'an herb',
 51 |     'a hereditary',
 52 |     'an hereditary',
 53 |     'a unist tree',
 54 |     'an mdast tree',
 55 | 
 56 |     'This is a test sentence',
 57 |     'It was an hour ago',
 58 |     'A unidirectional flow',
 59 |     'A unified thing',
 60 |     'A university is',
 61 |     'A one-way street',
 62 |     'An hour’s work',
 63 |     'Going to an “industry party”',
 64 |     'An 8-year old boy',
 65 |     'An 18-year old boy',
 66 |     'a 1px border',
 67 |     'a 100m sprint',
 68 |     'a 1rem font size',
 69 |     'a 1/4" hole',
 70 |     'a 1-off thing',
 71 |     'a 1x increase',
 72 |     'a 1:1 correspondence',
 73 |     'a 1:00 train',
 74 |     'a 1.0 release',
 75 |     'an h1',
 76 |     'an h6',
 77 |     'The A-levels are',
 78 |     'An NOP check',
 79 |     'A USA-wide license',
 80 |     'asked a UN member',
 81 |     'In an un-united Germany',
 82 |     'Here, a and b are supplementary angles',
 83 |     'Station A equals station B',
 84 |     'A University',
 85 |     'a unique identifier',
 86 |     'A Europe wide thing',
 87 |     'an npm package',
 88 |     'A. R.J. Turgot',
 89 |     'an MSc',
 90 |     'an XMR-based',
 91 |     "plural A’s, A's, As, as, or a’s, a's.",
 92 |     'They form a union and get laws passed.',
 93 |     // Don’t fail without words.
 94 |     'Station N equals station A',
 95 |     'Station N equals station A.',
 96 |     'a.',
 97 |     'an.',
 98 |     'a "',
 99 |     'a (',
100 |     // Punctuation.
101 |     'an “hour',
102 |     'a "bicycle"',
103 |     'a unicycle'
104 |   ]
105 | 
106 |   let index = -1
107 | 
108 |   while (++index < good.length) {
109 |     const value = good[index]
110 | 
111 |     await t.test(
112 |       'should work on good `' + highlight(value) + '`',
113 |       async function () {
114 |         const file = await retext().use(retextIndefiniteArticle).process(value)
115 |         assert.deepEqual(file.messages.map(String), [])
116 |       }
117 |     )
118 |   }
119 | 
120 |   const bad = [
121 |     'was a hour ago',
122 |     'was an sentence',
123 |     'An unidirectional flow',
124 |     'was a uninteresting',
125 |     'An university',
126 |     'A uninteresting',
127 |     'A hour’s work',
128 |     'to a “industry party”',
129 |     '"It was a uninteresting talk"',
130 |     'then an University',
131 |     'A 8-year old',
132 |     'A 18-year old',
133 |     'An 1/4" hole',
134 |     'An 1-off thing',
135 |     'an 1:1 correspondence',
136 |     'an 1:00 train',
137 |     'a h1',
138 |     'a h6',
139 |     'asked an UN member',
140 |     'In a un-united Germany',
141 |     'Anyone for a MSc?',
142 |     'They form an union and get laws passed.',
143 |     'an unicycle',
144 |     'an URL'
145 |   ]
146 | 
147 |   index = -1
148 | 
149 |   while (++index < bad.length) {
150 |     const value = bad[index]
151 | 
152 |     await t.test(
153 |       'should work on bad `' + highlight(value) + '`',
154 |       async function () {
155 |         const file = await retext().use(retextIndefiniteArticle).process(value)
156 |         assert.equal(file.messages.length, 1)
157 |       }
158 |     )
159 |   }
160 | })
161 | 
162 | /**
163 |  * @param {string} name
164 |  *   Value.
165 |  * @returns {name}
166 |  *   Value with `a` and `an` highlighted.
167 |  */
168 | function highlight(name) {
169 |   return name.replace(/\ban?\b/gi, function ($0) {
170 |     return chalk.bold($0)
171 |   })
172 | }
173 | 


--------------------------------------------------------------------------------
/tsconfig.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "compilerOptions": {
 3 |     "checkJs": true,
 4 |     "customConditions": ["development"],
 5 |     "declaration": true,
 6 |     "emitDeclarationOnly": true,
 7 |     "exactOptionalPropertyTypes": true,
 8 |     "lib": ["es2022"],
 9 |     "module": "node16",
10 |     "strict": true,
11 |     "target": "es2022"
12 |   },
13 |   "exclude": ["coverage/", "node_modules/"],
14 |   "include": ["**/*.js"]
15 | }
16 | 


--------------------------------------------------------------------------------