fix: ignore external https image links

BREAKING CHANGE: links like ![Image](./not-an-image.txt) will now report
an error

.github/workflows/lint.yml

@@ -10,10 +10,10 @@ jobs:
   lint:
     runs-on: "ubuntu-latest"
     steps:
-      - uses: "actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8" # v5.0.0
+      - uses: "actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd" # v6.0.2
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903" # v6.0.0
+        uses: "actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238" # v6.2.0
         with:
           node-version: "lts/*"
           cache: "npm"
@@ -21,15 +21,7 @@ jobs:
       - name: "Install dependencies"
         run: "npm clean-install"
 
-      - run: "node --run lint:editorconfig"
       - run: "node --run lint:markdown"
-      - run: "node --run lint:eslint"
-      - run: "node --run lint:prettier"
       - run: "node --run lint:typescript"
-
-  commitlint:
-    runs-on: "ubuntu-latest"
-    steps:
-      - uses: "actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8" # v5.0.0
-
-      - uses: "wagoid/commitlint-github-action@b948419dd99f3fd78a6548d48f94e3df7f6bf3ed" # v6.2.1
+      - run: "node --run lint:oxlint"
+      - run: "node --run lint:oxfmt"

.github/workflows/release.yml

@@ -4,6 +4,10 @@ on:
   push:
     branches: [main]
 
+permissions:
+  id-token: "write" # OIDC
+  contents: "read"
+
 jobs:
   release:
     runs-on: "ubuntu-latest"
@@ -13,13 +17,13 @@ jobs:
       pull-requests: "write"
       id-token: "write"
     steps:
-      - uses: "actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8" # v5.0.0
+      - uses: "actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd" # v6.0.2
         with:
           fetch-depth: 0
           persist-credentials: false
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903" # v6.0.0
+        uses: "actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238" # v6.2.0
         with:
           node-version: "lts/*"
           cache: "npm"
@@ -34,4 +38,3 @@ jobs:
         run: "node --run release"
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/test.yml

@@ -17,10 +17,10 @@ jobs:
           - "macos-latest"
     runs-on: "${{ matrix.runs-on }}"
     steps:
-      - uses: "actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8" # v5.0.0
+      - uses: "actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd" # v6.0.2
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903" # v6.0.0
+        uses: "actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238" # v6.2.0
         with:
           node-version: "lts/*"
           cache: "npm"

.oxfmtrc.json

@@ -0,0 +1,4 @@
+{
+  "$schema": "./node_modules/oxfmt/configuration_schema.json",
+  "semi": false
+}

.oxlintrc.json

@@ -0,0 +1,4 @@
+{
+  "$schema": "./node_modules/oxlint/configuration_schema.json",
+  "extends": ["node_modules/eslint-config-conventions/.oxlintrc.json"]
+}

.prettierrc.json

@@ -1,3 +0,0 @@
-{
-  "semi": false
-}

CONTRIBUTING.md

@@ -4,7 +4,7 @@ Thanks a lot for your interest in contributing to **markdownlint-rule-relative-l
 
 ## Code of Conduct
 
-**markdownlint-rule-relative-links** adopted the [Contributor Covenant](https://www.contributor-covenant.org/) as its Code of Conduct, and we expect project participants to adhere to it. Please read [the full text](/CODE_OF_CONDUCT.md) so that you can understand what actions will and will not be tolerated.
+**markdownlint-rule-relative-links** adopted the [Contributor Covenant](https://www.contributor-covenant.org/) as its Code of Conduct, and we expect project participants to adhere to it. Please read [the full text](./CODE_OF_CONDUCT.md) so that you can understand what actions will and will not be tolerated.
 
 ## Open Development
 

eslint.config.js

@@ -1,13 +0,0 @@
-import typescriptESLint from "typescript-eslint"
-import configConventions from "eslint-config-conventions"
-
-export default typescriptESLint.config(...configConventions, {
-  files: ["**/*.ts", "**/*.tsx"],
-  languageOptions: {
-    parser: typescriptESLint.parser,
-    parserOptions: {
-      projectService: true,
-      tsconfigRootDir: import.meta.dirname,
-    },
-  },
-})

package.json

@@ -1,62 +1,58 @@
 {
   "name": "markdownlint-rule-relative-links",
   "version": "0.0.0-development",
-  "public": true,
   "description": "Custom rule for markdownlint to validate relative links.",
-  "author": "Théo LUDWIG <contact@theoludwig.fr>",
-  "license": "MIT",
-  "repository": {
-    "type": "git",
-    "url": "https://github.com/theoludwig/markdownlint-rule-relative-links.git"
-  },
-  "bugs": {
-    "url": "https://github.com/theoludwig/markdownlint-rule-relative-links/issues"
-  },
-  "homepage": "https://github.com/theoludwig/markdownlint-rule-relative-links#readme",
   "keywords": [
     "markdownlint",
     "markdownlint-rule"
   ],
-  "main": "src/index.js",
-  "types": "src/index.d.ts",
-  "type": "module",
+  "homepage": "https://github.com/theoludwig/markdownlint-rule-relative-links#readme",
+  "bugs": {
+    "url": "https://github.com/theoludwig/markdownlint-rule-relative-links/issues"
+  },
+  "license": "MIT",
+  "author": "Théo LUDWIG <contact@theoludwig.fr>",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/theoludwig/markdownlint-rule-relative-links.git"
+  },
   "files": [
     "src"
   ],
+  "type": "module",
+  "main": "src/index.js",
+  "types": "src/index.d.ts",
   "publishConfig": {
     "access": "public",
     "provenance": true
   },
-  "engines": {
-    "node": ">=22.0.0"
-  },
   "scripts": {
-    "lint:editorconfig": "editorconfig-checker",
     "lint:markdown": "markdownlint-cli2",
-    "lint:eslint": "eslint . --max-warnings 0",
-    "lint:prettier": "prettier . --check",
     "lint:typescript": "tsc --noEmit",
+    "lint:oxlint": "oxlint . --deny-warnings --report-unused-disable-directives",
+    "lint:oxfmt": "oxfmt . --check",
+    "oxfmt": "oxfmt .",
     "test": "node --test",
     "release": "semantic-release"
   },
   "dependencies": {
-    "markdown-it": "14.1.0"
+    "markdown-it": "14.1.0",
+    "mime": "4.1.0"
   },
   "devDependencies": {
     "@types/markdown-it": "14.1.2",
-    "@types/node": "24.10.1",
-    "editorconfig-checker": "6.1.1",
-    "eslint": "9.39.1",
-    "eslint-config-conventions": "21.1.0",
-    "eslint-plugin-promise": "7.2.1",
-    "eslint-plugin-unicorn": "62.0.0",
-    "eslint-plugin-import-x": "4.16.1",
-    "globals": "16.5.0",
-    "markdownlint": "0.39.0",
-    "markdownlint-cli2": "0.19.0",
-    "prettier": "3.6.2",
-    "semantic-release": "25.0.2",
-    "typescript-eslint": "8.46.4",
+    "@types/node": "25.2.1",
+    "eslint-config-conventions": "21.2.0",
+    "markdownlint": "0.40.0",
+    "markdownlint-cli2": "0.20.0",
+    "oxfmt": "0.28.0",
+    "oxlint": "1.43.0",
+    "oxlint-tsgolint": "0.11.4",
+    "semantic-release": "25.0.3",
     "typescript": "5.9.3"
-  }
+  },
+  "engines": {
+    "node": ">=22.0.0"
+  },
+  "public": true
 }

src/index.js

@@ -1,5 +1,6 @@
-import { pathToFileURL } from "node:url"
+import { fileURLToPath, pathToFileURL } from "node:url"
 import fs from "node:fs"
+import mime from "mime"
 
 import { filterTokens } from "./markdownlint-rule-helpers/helpers.js"
 import {
@@ -69,11 +70,24 @@ const relativeLinksRule = {
           url = new URL(hrefSrc, pathToFileURL(params.name))
         }
 
-        if (url.protocol !== "file:") {
+        const detail = `"${hrefSrc}"`
+
+        if (
+          type === "image" &&
+          url.protocol !== "file:" &&
+          url.protocol !== "http:" &&
+          url.protocol !== "https:"
+        ) {
+          onError({
+            lineNumber,
+            detail: `${detail} should be an image`,
+          })
           continue
         }
 
-        const detail = `"${hrefSrc}"`
+        if (url.protocol !== "file:") {
+          continue
+        }
 
         if (!fs.existsSync(url)) {
           onError({
@@ -83,6 +97,15 @@ const relativeLinksRule = {
           continue
         }
 
+        const mimeType = mime.getType(fileURLToPath(url))
+        if (type === "image" && (mimeType == null || !mimeType.startsWith("image/"))) {
+          onError({
+            lineNumber,
+            detail: `${detail} should be an image`,
+          })
+          continue
+        }
+
         if (url.hash.length <= 0) {
           if (hrefSrc.includes("#")) {
             if (type === "image") {
@@ -116,8 +139,7 @@ const relativeLinksRule = {
 
         const fileContent = fs.readFileSync(url, { encoding: "utf8" })
         const headings = getMarkdownHeadings(fileContent)
-        const idOrAnchorNameHTMLFragments =
-          getMarkdownIdOrAnchorNameFragments(fileContent)
+        const idOrAnchorNameHTMLFragments = getMarkdownIdOrAnchorNameFragments(fileContent)
 
         /** @type {Map<string, number>} */
         const fragments = new Map()
@@ -136,9 +158,7 @@ const relativeLinksRule = {
 
         if (!fragmentsHTML.includes(url.hash)) {
           if (url.hash.startsWith("#L")) {
-            const lineNumberFragmentString = getLineNumberStringFromFragment(
-              url.hash,
-            )
+            const lineNumberFragmentString = getLineNumberStringFromFragment(url.hash)
 
             const hasOnlyDigits = isValidIntegerString(lineNumberFragmentString)
             if (!hasOnlyDigits) {
@@ -153,10 +173,7 @@ const relativeLinksRule = {
               continue
             }
 
-            const lineNumberFragment = Number.parseInt(
-              lineNumberFragmentString,
-              10,
-            )
+            const lineNumberFragment = Number.parseInt(lineNumberFragmentString, 10)
             const numberOfLines = getNumberOfLines(fileContent)
             if (lineNumberFragment > numberOfLines) {
               onError({

src/utils.js

@@ -23,10 +23,7 @@ export const convertHeadingToHTMLFragment = (inlineText) => {
         // RegExp source with Ruby's \p{Word} expanded into its General Categories
         // https://github.com/gjtorikian/html-pipeline/blob/main/lib/html/pipeline/toc_filter.rb
         // https://ruby-doc.org/core-3.0.2/Regexp.html
-        .replace(
-          /[^\p{Letter}\p{Mark}\p{Number}\p{Connector_Punctuation}\- ]/gu,
-          "",
-        )
+        .replace(/[^\p{Letter}\p{Mark}\p{Number}\p{Connector_Punctuation}\- ]/gu, "")
         .replace(/ /gu, "-"),
     )
   )
@@ -96,8 +93,7 @@ export const getMarkdownIdOrAnchorNameFragments = (content) => {
 
   for (const token of tokens) {
     const regexMatch =
-      idHTMLAttributeRegex.exec(token.content) ||
-      nameHTMLAttributeRegex.exec(token.content)
+      idHTMLAttributeRegex.exec(token.content) || nameHTMLAttributeRegex.exec(token.content)
     if (regexMatch == null) {
       continue
     }

test/fixtures/invalid/invalid-image.md

@@ -0,0 +1,5 @@
+# Invalid
+
+![Image](../not-an-image.txt)
+
+![Image 2](mailto:not-an-image@pictures.com)

test/fixtures/not-an-image.txt

@@ -0,0 +1 @@
+not an image

test/fixtures/valid/ignore-external-image.md

@@ -0,0 +1,3 @@
+# Valid
+
+![External Image](https://example.com/image.png)

test/index.test.js

@@ -35,22 +35,18 @@ test("ensure the rule validates correctly", async (t) => {
     const testCases = [
       {
         name: "should be invalid with an empty id fragment",
-        fixturePath:
-          "test/fixtures/invalid/empty-id-fragment/empty-id-fragment.md",
+        fixturePath: "test/fixtures/invalid/empty-id-fragment/empty-id-fragment.md",
         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",
-        errors: [
-          '"./awesome.md#name-should-be-ignored" should have a valid fragment identifier',
-        ],
+        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",
+        fixturePath: "test/fixtures/invalid/ignore-not-an-id-fragment/ignore-not-an-id-fragment.md",
         errors: [
           '"./awesome.md#not-an-id-should-be-ignored" should have a valid fragment identifier',
         ],
@@ -59,17 +55,13 @@ test("ensure the rule validates correctly", async (t) => {
         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',
-        ],
+        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",
-        errors: [
-          '"./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",
@@ -121,22 +113,16 @@ test("ensure the rule validates correctly", async (t) => {
         name: "should be invalid with a non-existing heading fragment",
         fixturePath:
           "test/fixtures/invalid/non-existing-heading-fragment/non-existing-heading-fragment.md",
-        errors: [
-          '"./awesome.md#non-existing-heading" should have a valid fragment identifier',
-        ],
+        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",
-        errors: [
-          '"../image.png#" should not have a fragment identifier as it is an image',
-        ],
+        fixturePath: "test/fixtures/invalid/ignore-empty-fragment-checking-for-image.md",
+        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",
+        fixturePath: "test/fixtures/invalid/ignore-fragment-checking-for-image.md",
         errors: [
           '"../image.png#non-existing-fragment" should not have a fragment identifier as it is an image',
         ],
@@ -161,30 +147,25 @@ test("ensure the rule validates correctly", async (t) => {
           },
         },
       },
+      {
+        name: "should be invalid with file with an image link that is not an image",
+        fixturePath: "test/fixtures/invalid/invalid-image.md",
+        errors: [
+          '"../not-an-image.txt" should be an image',
+          '"mailto:not-an-image@pictures.com" should be an image',
+        ],
+      },
     ]
 
-    for (const {
-      name,
-      fixturePath,
-      errors,
-      config = defaultConfig,
-    } of testCases) {
+    for (const { name, fixturePath, errors, config = defaultConfig } of testCases) {
       await t.test(name, async () => {
-        const lintResults =
-          (await validateMarkdownLint(fixturePath, config)) ?? []
+        const lintResults = (await validateMarkdownLint(fixturePath, config)) ?? []
         const errorsDetails = lintResults.map((result) => {
           assert.deepEqual(result.ruleNames, relativeLinksRule.names)
-          assert.deepEqual(
-            result.ruleDescription,
-            relativeLinksRule.description,
-          )
+          assert.deepEqual(result.ruleDescription, relativeLinksRule.description)
           return result.errorDetail
         })
-        assert.deepStrictEqual(
-          errorsDetails,
-          errors,
-          `${fixturePath}: Expected errors`,
-        )
+        assert.deepStrictEqual(errorsDetails, errors, `${fixturePath}: Expected errors`)
       })
     }
   })
@@ -203,8 +184,7 @@ test("ensure the rule validates correctly", async (t) => {
       },
       {
         name: "should be valid with an existing heading fragment",
-        fixturePath:
-          "test/fixtures/valid/existing-heading-fragment/existing-heading-fragment.md",
+        fixturePath: "test/fixtures/valid/existing-heading-fragment/existing-heading-fragment.md",
       },
       {
         name: 'should be valid with an existing heading fragment with accents (e.g: "é")',
@@ -228,8 +208,7 @@ test("ensure the rule validates correctly", async (t) => {
       },
       {
         name: "should be valid with valid line number fragment",
-        fixturePath:
-          "test/fixtures/valid/valid-line-number-fragment/valid-line-number-fragment.md",
+        fixturePath: "test/fixtures/valid/valid-line-number-fragment/valid-line-number-fragment.md",
       },
       {
         name: "should be valid with an existing file",
@@ -249,8 +228,7 @@ test("ensure the rule validates correctly", async (t) => {
       },
       {
         name: "should ignore checking fragment in own file",
-        fixturePath:
-          "test/fixtures/valid/ignore-fragment-checking-in-own-file.md",
+        fixturePath: "test/fixtures/valid/ignore-fragment-checking-in-own-file.md",
       },
       {
         name: "should be valid with correct absolute paths if root_path is set",
@@ -261,12 +239,15 @@ test("ensure the rule validates correctly", async (t) => {
           },
         },
       },
+      {
+        name: "should ignore external image links",
+        fixturePath: "test/fixtures/valid/ignore-external-image.md",
+      },
     ]
 
     for (const { name, fixturePath, config = defaultConfig } of testCases) {
       await t.test(name, async () => {
-        const lintResults =
-          (await validateMarkdownLint(fixturePath, config)) ?? []
+        const lintResults = (await validateMarkdownLint(fixturePath, config)) ?? []
         const errorsDetails = lintResults.map((result) => {
           return result.errorDetail
         })

test/utils.test.js

@@ -12,18 +12,13 @@ import {
 
 test("utils", async (t) => {
   await t.test("convertHeadingToHTMLFragment", async () => {
-    assert.strictEqual(
-      convertHeadingToHTMLFragment("Valid Fragments"),
-      "#valid-fragments",
-    )
+    assert.strictEqual(convertHeadingToHTMLFragment("Valid Fragments"), "#valid-fragments")
     assert.strictEqual(
       convertHeadingToHTMLFragment("Valid Heading With Underscores _"),
       "#valid-heading-with-underscores-_",
     )
     assert.strictEqual(
-      convertHeadingToHTMLFragment(
-        `Valid Heading With Quotes ' And Double Quotes "`,
-      ),
+      convertHeadingToHTMLFragment(`Valid Heading With Quotes ' And Double Quotes "`),
       "#valid-heading-with-quotes--and-double-quotes-",
     )
     assert.strictEqual(
@@ -33,27 +28,22 @@ test("utils", async (t) => {
   })
 
   await t.test("getMarkdownHeadings", async () => {
-    assert.deepStrictEqual(
-      getMarkdownHeadings("# Hello\n\n## World\n\n## Hello, world!\n"),
-      ["Hello", "World", "Hello, world!"],
-    )
+    assert.deepStrictEqual(getMarkdownHeadings("# Hello\n\n## World\n\n## Hello, world!\n"), [
+      "Hello",
+      "World",
+      "Hello, world!",
+    ])
   })
 
   await t.test("getMarkdownIdOrAnchorNameFragments", async () => {
     assert.deepStrictEqual(
-      getMarkdownIdOrAnchorNameFragments(
-        '<a name="anchorName" id="anchorId">Link</a>',
-      ),
+      getMarkdownIdOrAnchorNameFragments('<a name="anchorName" id="anchorId">Link</a>'),
       ["#anchorId"],
     )
-    assert.deepStrictEqual(
-      getMarkdownIdOrAnchorNameFragments('<a name="anchorName">Link</a>'),
-      ["#anchorName"],
-    )
-    assert.deepStrictEqual(
-      getMarkdownIdOrAnchorNameFragments("<a>Link</a>"),
-      [],
-    )
+    assert.deepStrictEqual(getMarkdownIdOrAnchorNameFragments('<a name="anchorName">Link</a>'), [
+      "#anchorName",
+    ])
+    assert.deepStrictEqual(getMarkdownIdOrAnchorNameFragments("<a>Link</a>"), [])
     assert.deepStrictEqual(getMarkdownIdOrAnchorNameFragments("<a>"), [])
     assert.deepStrictEqual(getMarkdownIdOrAnchorNameFragments("<a id=>"), [])
   })

tsconfig.json

@@ -8,7 +8,6 @@
     "allowJs": true,
     "noEmit": true,
     "rootDir": ".",
-    "baseUrl": ".",
     "skipLibCheck": true,
     "strict": true,
     "allowUnusedLabels": false,