no-undefined-references: add support for regex as option

Closes GH-296.
Closes GH-297.

Reviewed-by: JounQin <admin@1stg.me>
Reviewed-by: Titus Wormer <tituswormer@gmail.com>

packages/remark-lint-no-undefined-references/index.js

@@ -8,9 +8,12 @@
  * The following options (default: `undefined`) are accepted:
  *
  * *   `Object` with the following fields:
- *     *   `allow` (`Array<string>`, default: `[]`)
- *         — text that you want to allowed between `[` and `]` even though it’s
- *         undefined
+ *     *   `allow` (`Array<string | RegExp | { source: string }>`,
+ *         default: `[]`)
+ *         — text or regex that you want to be allowed between `[` and `]`
+ *         even though it’s undefined; regex is provided via a `RegExp` object
+ *         or via a `{ source: string }` object where `source` is the source
+ *         text of a case-insensitive regex
  *
  * ## Recommendation
  *
@@ -61,6 +64,15 @@
  *   > Eliding a portion of a quoted passage […] is acceptable.
  *
  * @example
+ *   {"name": "ok-allow.md", "config": {"allow": ["a", {"source": "^b\\."}]}}
+ *
+ *   [foo][b.c]
+ *
+ *   [bar][a]
+ *
+ *   Matching is case-insensitive: [bar][B.C]
+ *
+ * @example
  *   {"name": "not-ok.md", "label": "input"}
  *
  *   [bar]
@@ -93,6 +105,19 @@
  *   15:13-15:25: Found reference to undefined definition
  *   17:17-17:23: Found reference to undefined definition
  *   17:23-17:26: Found reference to undefined definition
+ *
+ * @example
+ *   {"name": "not-ok.md", "label": "input", "config": {"allow": ["a", {"source": "^b\\."}]}}
+ *
+ *   [foo][a.c]
+ *
+ *   [bar][b]
+ *
+ * @example
+ *   {"name": "not-ok.md", "label": "output", "config": {"allow": ["a", {"source": "^b\\."}]}}
+ *
+ *   1:1-1:11: Found reference to undefined definition
+ *   3:1-3:9: Found reference to undefined definition
  */
 
 /**
@@ -101,7 +126,7 @@
  * @typedef {import('mdast').Paragraph} Paragraph
  *
  * @typedef Options
- * @property {Array<string>} [allow]
+ * @property {Array<string | RegExp | { source: string }>} [allow]
  *
  * @typedef {Array<number>} Range
  */
@@ -123,12 +148,28 @@ const remarkLintNoUndefinedReferences = lintRule(
     const contents = String(file)
     const loc = location(file)
     const lineEnding = /(\r?\n|\r)[\t ]*(>[\t ]*)*/g
-    const allow = new Set(
-      (option.allow || []).map((d) => normalizeIdentifier(d))
-    )
     /** @type {Record<string, boolean>} */
     const map = Object.create(null)
 
+    const allow = option.allow || []
+    /** @type {Array<RegExp>} */
+    const regexes = []
+    /** @type {Set<string>} */
+    const strings = new Set()
+
+    let index = -1
+
+    while (++index < allow.length) {
+      const value = allow[index]
+      if (typeof value === 'string') {
+        strings.add(normalizeIdentifier(value))
+      } else if (value instanceof RegExp) {
+        regexes.push(value)
+      } else {
+        regexes.push(new RegExp(value.source, 'i'))
+      }
+    }
+
     visit(tree, (node) => {
       if (
         (node.type === 'definition' || node.type === 'footnoteDefinition') &&
@@ -148,7 +189,7 @@ const remarkLintNoUndefinedReferences = lintRule(
           node.type === 'footnoteReference') &&
         !generated(node) &&
         !(normalizeIdentifier(node.identifier) in map) &&
-        !allow.has(normalizeIdentifier(node.identifier))
+        !isAllowed(node.identifier)
       ) {
         file.message('Found reference to undefined definition', node)
       }
@@ -305,12 +346,24 @@ const remarkLintNoUndefinedReferences = lintRule(
         if (
           !generated({position: pos}) &&
           !(normalizeIdentifier(id) in map) &&
-          !allow.has(normalizeIdentifier(id))
+          !isAllowed(id)
         ) {
           file.message('Found reference to undefined definition', pos)
         }
       }
     }
+
+    /**
+     * @param {string} id
+     * @returns {boolean}
+     */
+    function isAllowed(id) {
+      const normalized = normalizeIdentifier(id)
+      return (
+        strings.has(normalized) ||
+        regexes.some((regex) => regex.test(normalized))
+      )
+    }
   }
 )
 

packages/remark-lint-no-undefined-references/readme.md

@@ -125,9 +125,12 @@ This rule supports standard configuration that all remark lint rules accept
 The following options (default: `undefined`) are accepted:
 
 *   `Object` with the following fields:
-    *   `allow` (`Array<string>`, default: `[]`)
-        — text that you want to allowed between `[` and `]` even though it’s
-        undefined
+    *   `allow` (`Array<string | RegExp | { source: string }>`,
+        default: `[]`)
+        — text or regex that you want to be allowed between `[` and `]`
+        even though it’s undefined; regex is provided via a `RegExp` object
+        or via a `{ source: string }` object where `source` is the source
+        text of a case-insensitive regex
 
 ## Recommendation
 
@@ -227,6 +230,43 @@ When configured with `{ allow: [ '...', '…' ] }`.
 
 No messages.
 
+##### `ok-allow.md`
+
+When configured with `{ allow: [ 'a', { source: '^b\\.' } ] }`.
+
+###### In
+
+```markdown
+[foo][b.c]
+
+[bar][a]
+
+Matching is case-insensitive: [bar][B.C]
+```
+
+###### Out
+
+No messages.
+
+##### `not-ok.md`
+
+When configured with `{ allow: [ 'a', { source: '^b\\.' } ] }`.
+
+###### In
+
+```markdown
+[foo][a.c]
+
+[bar][b]
+```
+
+###### Out
+
+```text
+1:1-1:11: Found reference to undefined definition
+3:1-3:9: Found reference to undefined definition
+```
+
 ## Compatibility
 
 Projects maintained by the unified collective are compatible with all maintained

test.js

@@ -21,6 +21,7 @@ import {characters} from './script/characters.js'
 import lint from './packages/remark-lint/index.js'
 import noHeadingPunctuation from './packages/remark-lint-no-heading-punctuation/index.js'
 import noMultipleToplevelHeadings from './packages/remark-lint-no-multiple-toplevel-headings/index.js'
+import noUndefinedReferences from './packages/remark-lint-no-undefined-references/index.js'
 import finalNewline from './packages/remark-lint-final-newline/index.js'
 
 const own = {}.hasOwnProperty
@@ -226,6 +227,21 @@ test('core', async (t) => {
     'should fail on incorrect severities (too low)'
   )
 
+  file = await remark()
+    .use(noUndefinedReferences, {allow: [/^b\./i]})
+    .process(
+      toVFile({
+        path: 'virtual.md',
+        value: ['[foo][b.c]', '', '[bar][b]'].join('\n')
+      })
+    )
+
+  t.deepEqual(
+    asStrings(file.messages),
+    ['virtual.md:3:1-3:9: Found reference to undefined definition'],
+    'no-undefined-references allow option should work with native regex'
+  )
+
   file = await remark()
     .use(
       lintRule('test:rule', (tree, file) => {