feat: improve errors message to distinguish between file system and f…

…ragment errors

README.md

@@ -21,7 +21,7 @@
 
 **markdownlint-rule-relative-links** is a [markdownlint](https://github.com/DavidAnson/markdownlint) custom rule to validate relative links.
 
-It ensures that relative links (using `file:` protocol) are working and not "dead" which means that it exists in the file system of the project that uses [markdownlint](https://github.com/DavidAnson/markdownlint).
+It ensures that relative links (using `file:` protocol) are working and exists in the file system of the project that uses [markdownlint](https://github.com/DavidAnson/markdownlint).
 
 ### Example
 
@@ -37,13 +37,13 @@ With `awesome.md` content:
 ```md
 [abc](./abc.txt)
 
-[Dead link](./dead.txt)
+[Invalid link](./invalid.txt)
 ```
 
 Running [markdownlint-cli2](https://github.com/DavidAnson/markdownlint-cli2) with `markdownlint-rule-relative-links` will output:
 
 ```sh
-awesome.md:3 relative-links Relative links should be valid [Link "./dead.txt" is dead]
+awesome.md:3 relative-links Relative links should be valid [Link "./invalid.txt" should exist in the file system]
 ```
 
 ### Related links

src/index.js

@@ -43,10 +43,14 @@ const customRule = {
           const isRelative =
             url.protocol === 'file:' && !hrefSrc.startsWith('/')
           if (isRelative) {
-            const detail = `Link "${hrefSrc}" is not valid`
+            const detail = `Link "${hrefSrc}"`
 
             if (!fs.existsSync(url)) {
-              addError(onError, lineNumber, detail)
+              addError(
+                onError,
+                lineNumber,
+                `${detail} should exist in the file system`
+              )
               return
             }
 
@@ -68,7 +72,11 @@ const customRule = {
               })
 
               if (!headingsHTMLFragments.includes(url.hash)) {
-                addError(onError, lineNumber, detail)
+                addError(
+                  onError,
+                  lineNumber,
+                  `${detail} should have a valid fragment`
+                )
               }
             }
           }

src/utils.js

@@ -41,8 +41,7 @@ const addError = (onError, lineNumber, detail, context, range, fixInfo) => {
  * Converts a Markdown heading into an HTML fragment according to the rules
  * used by GitHub.
  *
- * Taken from <https://github.com/DavidAnson/markdownlint/blob/d01180ec5a014083ee9d574b693a8d7fbc1e566d/lib/md051.js#L19>
- *
+ * @see https://github.com/DavidAnson/markdownlint/blob/d01180ec5a014083ee9d574b693a8d7fbc1e566d/lib/md051.js#L1
  * @param {string} inlineText Inline token for heading.
  * @returns {string} Fragment string for heading.
  */

test/basic.test.js

@@ -23,7 +23,7 @@ test('ensure the rule validate correctly', async () => {
   )
   assert.equal(
     lintResults['test/fixtures/Invalid.md'][0]?.errorDetail,
-    'Link "./basic.test.js" is not valid'
+    'Link "./basic.test.js" should exist in the file system'
   )
 
   assert.equal(
@@ -32,7 +32,7 @@ test('ensure the rule validate correctly', async () => {
   )
   assert.equal(
     lintResults['test/fixtures/Invalid.md'][1]?.errorDetail,
-    'Link "../image.png" is not valid'
+    'Link "../image.png" should exist in the file system'
   )
 
   assert.equal(
@@ -41,6 +41,6 @@ test('ensure the rule validate correctly', async () => {
   )
   assert.equal(
     lintResults['test/fixtures/Invalid.md'][2]?.errorDetail,
-    'Link "./Valid.md#not-existing-heading" is not valid'
+    'Link "./Valid.md#not-existing-heading" should have a valid fragment'
   )
 })