feat: stricter validation of heading fragments by being Case sensitive

Fixes #8

BREAKING CHANGE: Heading fragments is now Case sensitive.
For example "#ExistIng-Heading" is invalid as it should be "#existing-heading".

package.json

@@ -47,25 +47,25 @@
     "markdown-it": "14.1.0"
   },
   "devDependencies": {
-    "@commitlint/cli": "19.1.0",
+    "@commitlint/cli": "19.2.2",
-    "@commitlint/config-conventional": "19.1.0",
+    "@commitlint/config-conventional": "19.2.2",
-    "@types/markdown-it": "14.0.0",
+    "@types/markdown-it": "14.1.1",
-    "@types/node": "20.12.5",
+    "@types/node": "20.12.12",
     "editorconfig-checker": "5.1.5",
-    "eslint": "8.56.0",
+    "eslint": "8.57.0",
-    "eslint-config-conventions": "14.1.0",
+    "eslint-config-conventions": "14.2.0",
     "eslint-config-prettier": "9.1.0",
     "eslint-plugin-import": "2.29.1",
     "eslint-plugin-prettier": "5.1.3",
-    "eslint-plugin-promise": "6.1.1",
+    "eslint-plugin-promise": "6.2.0",
-    "eslint-plugin-unicorn": "51.0.1",
+    "eslint-plugin-unicorn": "53.0.0",
     "husky": "9.0.11",
-    "lint-staged": "15.2.2",
+    "lint-staged": "15.2.5",
     "markdownlint": "0.34.0",
     "markdownlint-cli2": "0.13.0",
     "pinst": "3.0.0",
     "prettier": "3.2.5",
-    "semantic-release": "23.0.7",
+    "semantic-release": "23.1.1",
-    "typescript": "5.4.4"
+    "typescript": "5.4.5"
   }
 }

src/index.js

@@ -11,6 +11,7 @@ const {
   isValidIntegerString,
   getNumberOfLines,
   getLineNumberStringFromFragment,
+  lineFragmentRe,
 } = require("./utils.js")
 
 /** @typedef {import('markdownlint').Rule} MarkdownLintRule */
@@ -125,7 +126,7 @@ const customRule = {
 
         fragmentsHTML.push(...idOrAnchorNameHTMLFragments)
 
-        if (!fragmentsHTML.includes(url.hash.toLowerCase())) {
+        if (!fragmentsHTML.includes(url.hash)) {
           if (url.hash.startsWith("#L")) {
             const lineNumberFragmentString = getLineNumberStringFromFragment(
               url.hash,
@@ -133,6 +134,10 @@ const customRule = {
 
             const hasOnlyDigits = isValidIntegerString(lineNumberFragmentString)
             if (!hasOnlyDigits) {
+              if (lineFragmentRe.test(url.hash)) {
+                continue
+              }
+
               onError({
                 lineNumber,
                 detail: `${detail} should have a valid fragment identifier`,
@@ -152,6 +157,8 @@ const customRule = {
               })
               continue
             }
+
+            continue
           }
 
           onError({

src/utils.js

@@ -4,6 +4,8 @@ const { getHtmlAttributeRe } = require("./markdownlint-rule-helpers/helpers.js")
 
 const markdownIt = new MarkdownIt({ html: true })
 
+const lineFragmentRe = /^#(?:L\d+(?:C\d+)?-L\d+(?:C\d+)?|L\d+)$/
+
 /**
  * Converts a Markdown heading into an HTML fragment according to the rules
  * used by GitHub.
@@ -26,7 +28,7 @@ const convertHeadingToHTMLFragment = (inlineText) => {
           "",
         )
         .replace(/ /gu, "-"),
-    ).toLowerCase()
+    )
   )
 }
 
@@ -151,6 +153,7 @@ const getLineNumberStringFromFragment = (fragment) => {
 }
 
 module.exports = {
+  lineFragmentRe,
   convertHeadingToHTMLFragment,
   getMarkdownHeadings,
   getMarkdownIdOrAnchorNameFragments,

test/fixtures/invalid/invalid-line-column-range-number-fragment/awesome.md

@@ -0,0 +1 @@
+# Awesome

test/fixtures/invalid/invalid-line-column-range-number-fragment/invalid-line-column-range-number-fragment.md

@@ -0,0 +1,31 @@
+# Invalid
+
+[Invalid](./awesome.md#L12-not-a-line-link)
+
+[Invalid](./awesome.md#l7)
+
+[Invalid](./awesome.md#L)
+
+[Invalid](./awesome.md#L7extra)
+
+[Invalid](./awesome.md#L30C)
+
+[Invalid](./awesome.md#L30Cextra)
+
+[Invalid](./awesome.md#L30L12)
+
+[Invalid](./awesome.md#L30C12)
+
+[Invalid](./awesome.md#L30C11-)
+
+[Invalid](./awesome.md#L30C11-L)
+
+[Invalid](./awesome.md#L30C11-L31C)
+
+[Invalid](./awesome.md#L30C11-C31)
+
+[Invalid](./awesome.md#C30)
+
+[Invalid](./awesome.md#C11-C31)
+
+[Invalid](./awesome.md#C11-L4C31)

test/fixtures/valid/valid-heading-like-number-fragment/valid-heading-like-number-fragment.md

@@ -1,3 +1,3 @@
 # Valid
 
-[Link fragment](./awesome.md#L7)
+[Link fragment](./awesome.md#l7)

test/fixtures/valid/valid-line-column-range-number-fragment/awesome.md

@@ -0,0 +1,3 @@
+# Awesome
+
+## L12 Not A Line Link

test/fixtures/valid/valid-line-column-range-number-fragment/valid-line-column-range-number-fragment.md

@@ -0,0 +1,11 @@
+# Valid
+
+[Valid](./awesome.md#l12-not-a-line-link)
+
+[Valid](./awesome.md#L30-L31)
+
+[Valid](./awesome.md#L3C24-L88)
+
+[Valid](./awesome.md#L304-L314C98)
+
+[Valid](./awesome.md#L200C4-L3244C2)

test/index.test.js

@@ -29,92 +29,138 @@ test("ensure the rule validates correctly", async (t) => {
         name: "should be invalid with an empty id fragment",
         fixturePath:
           "test/fixtures/invalid/empty-id-fragment/empty-id-fragment.md",
-        error: '"./awesome.md#" should have a valid fragment identifier',
+        errors: ['"./awesome.md#" should have a valid fragment identifier'],
       },
       {
         name: "should be invalid with a name fragment other than for an anchor",
         fixturePath:
           "test/fixtures/invalid/ignore-name-fragment-if-not-an-anchor/ignore-name-fragment-if-not-an-anchor.md",
-        error:
+        errors: [
           '"./awesome.md#name-should-be-ignored" should have a valid fragment identifier',
+        ],
       },
       {
         name: "should be invalid with a non-existing id fragment (data-id !== id)",
         fixturePath:
           "test/fixtures/invalid/ignore-not-an-id-fragment/ignore-not-an-id-fragment.md",
-        error:
+        errors: [
           '"./awesome.md#not-an-id-should-be-ignored" should have a valid fragment identifier',
+        ],
+      },
+      {
+        name: "should be invalid with uppercase letters in fragment (case sensitive)",
+        fixturePath:
+          "test/fixtures/invalid/invalid-heading-case-sensitive/invalid-heading-case-sensitive.md",
+        errors: [
+          '"./awesome.md#ExistIng-Heading" should have a valid fragment identifier',
+        ],
       },
       {
         name: "should be invalid with invalid heading with #L fragment",
         fixturePath:
           "test/fixtures/invalid/invalid-heading-with-L-fragment/invalid-heading-with-L-fragment.md",
-        error: '"./awesome.md#L7abc" should have a valid fragment identifier',
+        errors: [
+          '"./awesome.md#L7abc" should have a valid fragment identifier',
+        ],
+      },
+      {
+        name: "should be invalid with a invalid line column range number fragment",
+        fixturePath:
+          "test/fixtures/invalid/invalid-line-column-range-number-fragment/invalid-line-column-range-number-fragment.md",
+        errors: [
+          '"./awesome.md#L12-not-a-line-link" should have a valid fragment identifier',
+          '"./awesome.md#l7" should have a valid fragment identifier',
+          '"./awesome.md#L" should have a valid fragment identifier',
+          '"./awesome.md#L7extra" should have a valid fragment identifier',
+          '"./awesome.md#L30C" should have a valid fragment identifier',
+          '"./awesome.md#L30Cextra" should have a valid fragment identifier',
+          '"./awesome.md#L30L12" should have a valid fragment identifier',
+          '"./awesome.md#L30C12" should have a valid fragment identifier',
+          '"./awesome.md#L30C11-" should have a valid fragment identifier',
+          '"./awesome.md#L30C11-L" should have a valid fragment identifier',
+          '"./awesome.md#L30C11-L31C" should have a valid fragment identifier',
+          '"./awesome.md#L30C11-C31" should have a valid fragment identifier',
+          '"./awesome.md#C30" should have a valid fragment identifier',
+          '"./awesome.md#C11-C31" should have a valid fragment identifier',
+          '"./awesome.md#C11-L4C31" should have a valid fragment identifier',
+        ],
       },
       {
         name: "should be invalid with a invalid line number fragment",
         fixturePath:
           "test/fixtures/invalid/invalid-line-number-fragment/invalid-line-number-fragment.md",
-        error:
+        errors: [
           '"./awesome.md#L7" should have a valid fragment identifier, "./awesome.md#L7" should have at least 7 lines to be valid',
+        ],
       },
       {
         name: "should be invalid with a non-existing anchor name fragment",
         fixturePath:
           "test/fixtures/invalid/non-existing-anchor-name-fragment/non-existing-anchor-name-fragment.md",
-        error:
+        errors: [
           '"./awesome.md#non-existing-anchor-name-fragment" should have a valid fragment identifier',
+        ],
       },
       {
         name: "should be invalid with a non-existing element id fragment",
         fixturePath:
           "test/fixtures/invalid/non-existing-element-id-fragment/non-existing-element-id-fragment.md",
-        error:
+        errors: [
           '"./awesome.md#non-existing-element-id-fragment" should have a valid fragment identifier',
+        ],
       },
       {
         name: "should be invalid with a non-existing heading fragment",
         fixturePath:
           "test/fixtures/invalid/non-existing-heading-fragment/non-existing-heading-fragment.md",
-        error:
+        errors: [
           '"./awesome.md#non-existing-heading" should have a valid fragment identifier',
+        ],
       },
       {
         name: "should be invalid with a link to an image with a empty fragment",
         fixturePath:
           "test/fixtures/invalid/ignore-empty-fragment-checking-for-image.md",
-        error:
+        errors: [
           '"../image.png#" should not have a fragment identifier as it is an image',
+        ],
       },
       {
         name: "should be invalid with a link to an image with a fragment",
         fixturePath:
           "test/fixtures/invalid/ignore-fragment-checking-for-image.md",
-        error:
+        errors: [
           '"../image.png#non-existing-fragment" should not have a fragment identifier as it is an image',
+        ],
       },
       {
         name: "should be invalid with a non-existing file",
         fixturePath: "test/fixtures/invalid/non-existing-file.md",
-        error: '"./index.test.js" should exist in the file system',
+        errors: ['"./index.test.js" should exist in the file system'],
       },
       {
         name: "should be invalid with a non-existing image",
         fixturePath: "test/fixtures/invalid/non-existing-image.md",
-        error: '"./image.png" should exist in the file system',
+        errors: ['"./image.png" should exist in the file system'],
       },
     ]
 
-    for (const { name, fixturePath, error } of testCases) {
+    for (const { name, fixturePath, errors } of testCases) {
       await t.test(name, async () => {
-        const lintResults = await validateMarkdownLint(fixturePath)
+        const lintResults = (await validateMarkdownLint(fixturePath)) ?? []
-        assert.equal(lintResults?.length, 1)
+        const errorsDetails = lintResults.map((result) => {
-        assert.deepEqual(lintResults?.[0]?.ruleNames, relativeLinksRule.names)
+          assert.deepEqual(result.ruleNames, relativeLinksRule.names)
-        assert.equal(
+          assert.deepEqual(
-          lintResults?.[0]?.ruleDescription,
+            result.ruleDescription,
             relativeLinksRule.description,
           )
-        assert.equal(lintResults?.[0]?.errorDetail, error)
+          return result.errorDetail
+        })
+        assert.deepStrictEqual(
+          errorsDetails,
+          errors,
+          `${fixturePath}: Expected errors`,
+        )
       })
     }
   })
@@ -131,11 +177,6 @@ test("ensure the rule validates correctly", async (t) => {
         fixturePath:
           "test/fixtures/valid/existing-element-id-fragment/existing-element-id-fragment.md",
       },
-      {
-        name: "should be valid with an existing heading fragment (case insensitive)",
-        fixturePath:
-          "test/fixtures/valid/existing-heading-case-insensitive/existing-heading-case-insensitive.md",
-      },
       {
         name: "should be valid with an existing heading fragment",
         fixturePath:
@@ -151,6 +192,11 @@ test("ensure the rule validates correctly", async (t) => {
         fixturePath:
           "test/fixtures/valid/only-parse-markdown-files-for-fragments/only-parse-markdown-files-for-fragments.md",
       },
+      {
+        name: "should support lines and columns range numbers in link fragments",
+        fixturePath:
+          "test/fixtures/valid/valid-line-column-range-number-fragment/valid-line-column-range-number-fragment.md",
+      },
       {
         name: 'should be valid with valid heading "like" line number fragment',
         fixturePath:
@@ -186,8 +232,15 @@ test("ensure the rule validates correctly", async (t) => {
 
     for (const { name, fixturePath } of testCases) {
       await t.test(name, async () => {
-        const lintResults = await validateMarkdownLint(fixturePath)
+        const lintResults = (await validateMarkdownLint(fixturePath)) ?? []
-        assert.equal(lintResults?.length, 0)
+        const errorsDetails = lintResults.map((result) => {
+          return result.errorDetail
+        })
+        assert.equal(
+          errorsDetails.length,
+          0,
+          `${fixturePath}: Expected no errors, got ${errorsDetails.join(", ")}`,
+        )
       })
     }
   })