Refactor code-style

lib/check-files.js

@@ -0,0 +1,49 @@
+/**
+ * @typedef {import('./index.js').Landmarks} Landmarks
+ */
+
+import {constants, promises as fs} from 'node:fs'
+
+/**
+ * @param {Landmarks} landmarks
+ *   Landmarks.
+ * @param {ReadonlyArray<string>} references
+ *   References.
+ * @returns {Promise<undefined>}
+ *   Nothing.
+ */
+export async function checkFiles(landmarks, references) {
+  /** @type {Array<Promise<undefined>>} */
+  const promises = []
+
+  for (const filePath of references) {
+    const marks = landmarks.get(filePath)
+
+    if (!marks) {
+      /** @type {Map<string, boolean>} */
+      const map = new Map()
+
+      landmarks.set(filePath, map)
+
+      promises.push(
+        fs.access(filePath, constants.F_OK).then(
+          /**
+           * @returns {undefined}
+           */
+          function () {
+            map.set('', true)
+          },
+          /**
+           * @param {NodeJS.ErrnoException} error
+           * @returns {undefined}
+           */
+          function (error) {
+            map.set('', error.code !== 'ENOENT' && error.code !== 'ENOTDIR')
+          }
+        )
+      )
+    }
+  }
+
+  await Promise.all(promises)
+}

lib/constants.js

@@ -1,8 +1,8 @@
-export const constants = {
-  sourceId: 'remark-validate-links',
-  headingRuleId: 'missing-heading',
-  headingInFileRuleId: 'missing-heading-in-file',
+export const constants = /** @type {const} */ ({
   fileRuleId: 'missing-file',
+  headingInFileRuleId: 'missing-heading-in-file',
+  headingRuleId: 'missing-heading',
   landmarkId: 'remarkValidateLinksLandmarks',
-  referenceId: 'remarkValidateLinksReferences'
-}
+  referenceId: 'remarkValidateLinksReferences',
+  sourceId: 'remark-validate-links'
+})