feat: truncate short description exceeding the byte limit (#143)

* feat: truncate short description exceeding the byte limit

* fix tests

.github/dependabot.yml

@@ -4,6 +4,7 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+      day: "sunday"
     labels:
       - "dependencies"
 
@@ -11,5 +12,10 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
-    allow:
-      - dependency-name: "@actions/*"
+      day: "sunday"
+    ignore:
+      - dependency-name: "*"
+        update-types: ["version-update:semver-major"]
+    labels:
+      - "dependencies"
+ 

.github/workflows/automerge-dependabot.yml

@@ -0,0 +1,13 @@
+name: Auto-merge Dependabot
+on: pull_request
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
+    steps:
+      - uses: peter-evans/enable-pull-request-automerge@v3
+        with:
+          token: ${{ secrets.ACTIONS_BOT_TOKEN }}
+          pull-request-number: ${{ github.event.pull_request.number }}
+          merge-method: squash

.github/workflows/ci.yml

@@ -23,6 +23,7 @@ jobs:
       - uses: actions/setup-node@v3
         with:
           node-version: 16.x
+          cache: npm
       - run: npm ci
       - run: npm run build
       - run: npm run format-check
@@ -93,6 +94,7 @@ jobs:
       - name: Create Pull Request
         uses: peter-evans/create-pull-request@v4
         with:
+          token: ${{ secrets.ACTIONS_BOT_TOKEN }}
           commit-message: 'build: update distribution'
           title: Update distribution
           body: |

.github/workflows/update-major-version.yml

@@ -0,0 +1,31 @@
+name: Update Major Version
+run-name: Update ${{ github.event.inputs.main_version }} to ${{ github.event.inputs.target }}
+
+on:
+  workflow_dispatch:
+    inputs:
+      target:
+        description: The target tag or reference
+        required: true
+      main_version:
+        type: choice
+        description: The major version tag to update
+        options:
+          - v3
+
+jobs:
+  tag:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        token: ${{ secrets.ACTIONS_BOT_TOKEN }}
+        fetch-depth: 0
+    - name: Git config
+      run: |
+        git config user.name actions-bot
+        git config user.email actions-bot@users.noreply.github.com
+    - name: Tag new target
+      run: git tag -f ${{ github.event.inputs.main_version }} ${{ github.event.inputs.target }}
+    - name: Push new tag
+      run: git push origin ${{ github.event.inputs.main_version }} --force

README.md

@@ -25,11 +25,15 @@ This is useful if you `docker push` your images to Docker Hub. It provides an ea
 | `repository` | Docker Hub repository in the format `<namespace>/<name>`. | `github.repository` |
 | `short-description` | Docker Hub repository short description. | |
 | `readme-filepath` | Path to the repository readme. | `./README.md` |
+| `enable-url-completion` | Enables completion of relative URLs to absolute ones. See also [known Issues](#url-completion-known-issues). | `false` |
+| `image-extensions` | File extensions that will be treated as images. | `bmp,gif,jpg,jpeg,png,svg,webp` |
 
 #### Content limits
 
-DockerHub has content limits, which if exceeded will result in the content being automatically truncated.
+DockerHub has content limits.
 The readme content is limited to 25,000 bytes, and `short-description` is limited to 100 characters.
+This action truncates content to prevent the request being rejected.
+If the content has been truncated a warning will be issued in the run log.
 
 #### Specifying the file path
 
@@ -86,6 +90,7 @@ jobs:
         password: ${{ secrets.DOCKERHUB_PASSWORD }}
         repository: peterevans/dockerhub-description
         short-description: ${{ github.event.repository.description }}
+        enable-url-completion: true
 ```
 
 Updates the Docker Hub repository description whenever a new release is created.
@@ -108,6 +113,38 @@ jobs:
         short-description: ${{ github.event.repository.description }}
 ```
 
+### URL completion known Issues
+
+The completion of relative URLs has some known issues:
+
+1. Relative markdown links in inline-code and code blocks **are also converted**:
+
+   ```markdown
+   [link in inline code](#table-of-content)
+   ```
+
+   will be converted into
+
+   ```markdown
+   [link in inline code](https://github.com/peter-evans/dockerhub-description/blob/main/./README.md#table-of-content)
+   ```
+
+2. Links containing square brackets (`]`) in the text fragment **are not converted**:
+
+   ```markdown
+   [[link text with square brackets]](#table-of-content)
+   ```
+
+3. [Reference-style links/images](https://www.markdownguide.org/basic-syntax/#reference-style-links) **are not converted**.
+
+   ```markdown
+   [table-of-content][toc]
+
+   ...
+
+   [toc]: #table-of-content "Table of content"
+   ```
+
 ## Using the Docker image independently of GitHub Actions
 
 The image can be executed in other environments independently of GitHub Actions.

__test__/readme-helper.unit.test.ts

@@ -0,0 +1,335 @@
+import {completeRelativeUrls} from '../src/readme-helper'
+
+describe('complete relative urls tests', () => {
+  const GITHUB_SERVER_URL = process.env['GITHUB_SERVER_URL']
+  const GITHUB_REPOSITORY = process.env['GITHUB_REPOSITORY']
+  const GITHUB_REF_NAME = process.env['GITHUB_REF_NAME']
+
+  const README_FILEPATH = './README.md'
+  const EXPECTED_REPOSITORY_URL = `${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}`
+  const EXPECTED_BLOB_URL = `${EXPECTED_REPOSITORY_URL}/blob/${GITHUB_REF_NAME}`
+  const EXPECTED_RAW_URL = `${EXPECTED_REPOSITORY_URL}/raw/${GITHUB_REF_NAME}`
+
+  // known issues
+  test('reference-style links/image sources are not converted', async () => {
+    const content = [
+      'table-of-content][toc]',
+      '',
+      '[toc]: #table-of-content "Table of content"'
+    ].join('\n')
+    expect(completeRelativeUrls(content, README_FILEPATH, true, '')).toEqual(
+      content
+    )
+  })
+
+  test('links containing square brackets in the text fragment are not converted', async () => {
+    expect(
+      completeRelativeUrls(
+        '[[text with square brackets]](README.md)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual('[[text with square brackets]](README.md)')
+  })
+
+  test('links containing square brackets in the text fragment are not converted', async () => {
+    expect(
+      completeRelativeUrls('`[text](README.md)`', README_FILEPATH, true, '')
+    ).toEqual(`\`[text](${EXPECTED_BLOB_URL}/README.md)\``)
+  })
+
+  // misc
+  test('do not change content when disabled', async () => {
+    expect(
+      completeRelativeUrls('[text](README.md)', README_FILEPATH, false, '')
+    ).toEqual('[text](README.md)')
+  })
+
+  test('do not change link with mailto protocol', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](mailto:mail@example.com)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(`[text](mailto:mail@example.com)`)
+  })
+
+  test('do not change link with ftp protocol', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](ftp://example.com)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(`[text](ftp://example.com)`)
+  })
+
+  test('do not change link with http protocol', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](http://example.com)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(`[text](http://example.com)`)
+  })
+
+  test('do not change link with https protocol', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](https://example.com)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(`[text](https://example.com)`)
+  })
+
+  test('do not change link with protocol-like beginning', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](abc://example.com)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(`[text](abc://example.com)`)
+  })
+
+  test('do not change image from absolute source with absolute link', async () => {
+    expect(
+      completeRelativeUrls(
+        '[![alttext](https://example.com/image.svg)](https://example.com/image.svg)',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(
+      `[![alttext](https://example.com/image.svg)](https://example.com/image.svg)`
+    )
+  })
+
+  // anchors
+  test('anchor referencing the current document', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](#relative-anchor)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(`[text](${EXPECTED_BLOB_URL}/README.md#relative-anchor)`)
+  })
+
+  test('anchor referencing the current document with a title', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](#relative-anchor "the anchor (a title)")',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(
+      `[text](${EXPECTED_BLOB_URL}/README.md#relative-anchor "the anchor (a title)")`
+    )
+  })
+
+  test('anchor referencing the current document with a title and unicode', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text with 🌬](#relative-anchor "the anchor (a title with 🌬)")',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(
+      `[text with 🌬](${EXPECTED_BLOB_URL}/README.md#relative-anchor "the anchor (a title with 🌬)")`
+    )
+  })
+
+  test('anchor referencing another document', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](OTHER.md#absolute-anchor)',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(`[text](${EXPECTED_BLOB_URL}/OTHER.md#absolute-anchor)`)
+  })
+
+  test('anchor referencing another document with a title', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](OTHER.md#absolute-anchor "the anchor (a title)")',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(
+      `[text](${EXPECTED_BLOB_URL}/OTHER.md#absolute-anchor "the anchor (a title)")`
+    )
+  })
+
+  test('anchor with image referencing the current document', async () => {
+    expect(
+      completeRelativeUrls(
+        '[![alttext](image.svg)](#absolute-anchor "the anchor (a title)")',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(
+      `[![alttext](${EXPECTED_RAW_URL}/image.svg)](${EXPECTED_BLOB_URL}/README.md#absolute-anchor "the anchor (a title)")`
+    )
+  })
+
+  test('anchor with image referencing another document', async () => {
+    expect(
+      completeRelativeUrls(
+        '[![alttext](image.svg)](OTHER.md#absolute-anchor "the anchor (a title)")',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(
+      `[![alttext](${EXPECTED_RAW_URL}/image.svg)](${EXPECTED_BLOB_URL}/OTHER.md#absolute-anchor "the anchor (a title)")`
+    )
+  })
+
+  // documents
+  test('text document', async () => {
+    expect(
+      completeRelativeUrls('[text](document.yaml)', README_FILEPATH, true, '')
+    ).toEqual(`[text](${EXPECTED_BLOB_URL}/document.yaml)`)
+  })
+
+  test('pdf document', async () => {
+    expect(
+      completeRelativeUrls('[text](document.pdf)', README_FILEPATH, true, '')
+    ).toEqual(`[text](${EXPECTED_BLOB_URL}/document.pdf)`)
+  })
+
+  test('document with a title', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text](document.pdf "the document (a title)")',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(
+      `[text](${EXPECTED_BLOB_URL}/document.pdf "the document (a title)")`
+    )
+  })
+
+  test('document with a title and unicode', async () => {
+    expect(
+      completeRelativeUrls(
+        '[text with 🌬](document.pdf "the document (a title with 🌬)")',
+        README_FILEPATH,
+        true,
+        ''
+      )
+    ).toEqual(
+      `[text with 🌬](${EXPECTED_BLOB_URL}/document.pdf "the document (a title with 🌬)")`
+    )
+  })
+
+  // images
+  test('image with supported file extension', async () => {
+    expect(
+      completeRelativeUrls(
+        '![alttext](image.svg)',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(`![alttext](${EXPECTED_RAW_URL}/image.svg)`)
+  })
+
+  test('image with unsupported file extension', async () => {
+    expect(
+      completeRelativeUrls(
+        '![alttext](image.svg)',
+        README_FILEPATH,
+        true,
+        'jpeg'
+      )
+    ).toEqual(`![alttext](${EXPECTED_BLOB_URL}/image.svg)`)
+  })
+
+  test('image without alternate text', async () => {
+    expect(
+      completeRelativeUrls('![](image.svg)', README_FILEPATH, true, 'svg')
+    ).toEqual(`![](${EXPECTED_RAW_URL}/image.svg)`)
+  })
+
+  test('image with a title', async () => {
+    expect(
+      completeRelativeUrls(
+        '![alttext](image.svg "the image (a title)")',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(`![alttext](${EXPECTED_RAW_URL}/image.svg "the image (a title)")`)
+  })
+
+  test('image with relative link', async () => {
+    expect(
+      completeRelativeUrls(
+        '[![alttext](image.svg)](image.svg)',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(
+      `[![alttext](${EXPECTED_RAW_URL}/image.svg)](${EXPECTED_BLOB_URL}/image.svg)`
+    )
+  })
+
+  test('image with a title, unicode and relative link', async () => {
+    expect(
+      completeRelativeUrls(
+        '[![alttext with 🌬](image.🌬.svg "the image.🌬.svg (a title)")](image.🌬.svg)',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(
+      `[![alttext with 🌬](${EXPECTED_RAW_URL}/image.🌬.svg "the image.🌬.svg (a title)")](${EXPECTED_BLOB_URL}/image.🌬.svg)`
+    )
+  })
+
+  test('image from absolute source with relative link', async () => {
+    expect(
+      completeRelativeUrls(
+        '[![alttext](https://example.com/image.svg)](image.svg)',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(
+      `[![alttext](https://example.com/image.svg)](${EXPECTED_BLOB_URL}/image.svg)`
+    )
+  })
+
+  test('image with absolute link', async () => {
+    expect(
+      completeRelativeUrls(
+        '[![alttext](image.svg)](https://example.com/image.svg)',
+        README_FILEPATH,
+        true,
+        'svg'
+      )
+    ).toEqual(
+      `[![alttext](${EXPECTED_RAW_URL}/image.svg)](https://example.com/image.svg)`
+    )
+  })
+})

__test__/utils.unit.test.ts

@@ -0,0 +1,10 @@
+import {truncateToBytes} from '../src/utils'
+
+describe('truncate to bytes tests', () => {
+  test('unicode aware truncation to a number of bytes', async () => {
+    expect(truncateToBytes('test string to be truncated', 10)).toEqual(
+      'test strin'
+    )
+    expect(truncateToBytes('😀😁😂🤣😃😄😅', 10)).toEqual('😀😁')
+  })
+})

action.yml

@@ -18,6 +18,14 @@ inputs:
     description: >
       Path to the repository readme
       Default: `./README.md`
+  enable-url-completion:
+    description: >
+      Enables completion of relative URLs to absolute ones
+      Default: `false`
+  image-extensions:
+    description: >
+      File extensions that will be treated as images
+      Default: `bmp,gif,jpg,jpeg,png,svg,webp`
 runs:
   using: 'node16'
   main: 'dist/index.js'

dist/index.js

@@ -8,7 +8,11 @@
 
 var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
-    Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
 }) : (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
     o[k2] = m[k];
@@ -38,7 +42,6 @@ Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.updateRepositoryDescription = exports.getToken = void 0;
 const core = __importStar(__nccwpck_require__(2186));
 const fetch = __importStar(__nccwpck_require__(467));
-const DESCRIPTION_MAX_CHARS = 100;
 function getToken(username, password) {
     return __awaiter(this, void 0, void 0, function* () {
         const body = {
@@ -65,7 +68,7 @@ function updateRepositoryDescription(token, repository, description, fullDescrip
             full_description: fullDescription
         };
         if (description) {
-            body['description'] = description.slice(0, DESCRIPTION_MAX_CHARS);
+            body['description'] = description;
         }
         yield fetch(`https://hub.docker.com/v2/repositories/${repository}`, {
             method: 'patch',
@@ -93,7 +96,11 @@ exports.updateRepositoryDescription = updateRepositoryDescription;
 
 var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
-    Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
 }) : (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
     o[k2] = m[k];
@@ -113,14 +120,16 @@ var __importStar = (this && this.__importStar) || function (mod) {
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.validateInputs = exports.getInputs = void 0;
 const core = __importStar(__nccwpck_require__(2186));
-const README_FILEPATH_DEFAULT = './README.md';
+const readmeHelper = __importStar(__nccwpck_require__(3367));
 function getInputs() {
     const inputs = {
         username: core.getInput('username'),
         password: core.getInput('password'),
         repository: core.getInput('repository'),
         shortDescription: core.getInput('short-description'),
-        readmeFilepath: core.getInput('readme-filepath')
+        readmeFilepath: core.getInput('readme-filepath'),
+        enableUrlCompletion: Boolean(core.getInput('enable-url-completion')),
+        imageExtensions: core.getInput('image-extensions')
     };
     // Environment variable input alternatives and their aliases
     if (!inputs.username && process.env['DOCKERHUB_USERNAME']) {
@@ -147,15 +156,28 @@ function getInputs() {
     if (!inputs.readmeFilepath && process.env['README_FILEPATH']) {
         inputs.readmeFilepath = process.env['README_FILEPATH'];
     }
+    if (!inputs.enableUrlCompletion && process.env['ENABLE_URL_COMPLETION']) {
+        inputs.enableUrlCompletion = Boolean(process.env['ENABLE_URL_COMPLETION']);
+    }
+    if (!inputs.imageExtensions && process.env['IMAGE_EXTENSIONS']) {
+        inputs.imageExtensions = process.env['IMAGE_EXTENSIONS'];
+    }
     // Set defaults
     if (!inputs.readmeFilepath) {
-        inputs.readmeFilepath = README_FILEPATH_DEFAULT;
+        inputs.readmeFilepath = readmeHelper.README_FILEPATH_DEFAULT;
+    }
+    if (!inputs.enableUrlCompletion) {
+        inputs.enableUrlCompletion = readmeHelper.ENABLE_URL_COMPLETION_DEFAULT;
+    }
+    if (!inputs.imageExtensions) {
+        inputs.imageExtensions = readmeHelper.IMAGE_EXTENSIONS_DEFAULT;
     }
     if (!inputs.repository && process.env['GITHUB_REPOSITORY']) {
         inputs.repository = process.env['GITHUB_REPOSITORY'];
     }
-    // Docker repositories must be all lower case
+    // Enforce lower case, where needed
     inputs.repository = inputs.repository.toLowerCase();
+    inputs.imageExtensions = inputs.imageExtensions.toLowerCase();
     return inputs;
 }
 exports.getInputs = getInputs;
@@ -180,7 +202,11 @@ exports.validateInputs = validateInputs;
 
 var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
-    Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
 }) : (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
     o[k2] = m[k];
@@ -210,13 +236,10 @@ Object.defineProperty(exports, "__esModule", ({ value: true }));
 const core = __importStar(__nccwpck_require__(2186));
 const inputHelper = __importStar(__nccwpck_require__(5480));
 const dockerhubHelper = __importStar(__nccwpck_require__(1812));
-const fs = __importStar(__nccwpck_require__(7147));
+const readmeHelper = __importStar(__nccwpck_require__(3367));
+const utils = __importStar(__nccwpck_require__(918));
 const util_1 = __nccwpck_require__(3837);
-function getErrorMessage(error) {
-    if (error instanceof Error)
-        return error.message;
-    return String(error);
-}
+const SHORT_DESCRIPTION_MAX_BYTES = 100;
 function run() {
     return __awaiter(this, void 0, void 0, function* () {
         try {
@@ -224,9 +247,14 @@ function run() {
             core.debug(`Inputs: ${(0, util_1.inspect)(inputs)}`);
             inputHelper.validateInputs(inputs);
             // Fetch the readme content
-            const readmeContent = yield fs.promises.readFile(inputs.readmeFilepath, {
-                encoding: 'utf8'
-            });
+            core.info('Reading description source file');
+            const readmeContent = yield readmeHelper.getReadmeContent(inputs.readmeFilepath, inputs.enableUrlCompletion, inputs.imageExtensions);
+            core.debug(readmeContent);
+            // Truncate the short description if it is too long
+            const truncatedShortDescription = utils.truncateToBytes(inputs.shortDescription, SHORT_DESCRIPTION_MAX_BYTES);
+            if (truncatedShortDescription.length !== inputs.shortDescription.length) {
+                core.warning(`The short description exceeds DockerHub's limit and has been truncated to ${SHORT_DESCRIPTION_MAX_BYTES} bytes.`);
+            }
             // Acquire a token for the Docker Hub API
             core.info('Acquiring token');
             const token = yield dockerhubHelper.getToken(inputs.username, inputs.password);
@@ -237,13 +265,206 @@ function run() {
         }
         catch (error) {
             core.debug((0, util_1.inspect)(error));
-            core.setFailed(getErrorMessage(error));
+            core.setFailed(utils.getErrorMessage(error));
         }
     });
 }
 run();
 
 
+/***/ }),
+
+/***/ 3367:
+/***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
+
+"use strict";
+
+var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
+}) : (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    o[k2] = m[k];
+}));
+var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
+    Object.defineProperty(o, "default", { enumerable: true, value: v });
+}) : function(o, v) {
+    o["default"] = v;
+});
+var __importStar = (this && this.__importStar) || function (mod) {
+    if (mod && mod.__esModule) return mod;
+    var result = {};
+    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
+    __setModuleDefault(result, mod);
+    return result;
+};
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+Object.defineProperty(exports, "__esModule", ({ value: true }));
+exports.completeRelativeUrls = exports.getReadmeContent = exports.ENABLE_URL_COMPLETION_DEFAULT = exports.IMAGE_EXTENSIONS_DEFAULT = exports.README_FILEPATH_DEFAULT = void 0;
+const core = __importStar(__nccwpck_require__(2186));
+const fs = __importStar(__nccwpck_require__(7147));
+const utils = __importStar(__nccwpck_require__(918));
+exports.README_FILEPATH_DEFAULT = './README.md';
+exports.IMAGE_EXTENSIONS_DEFAULT = 'bmp,gif,jpg,jpeg,png,svg,webp';
+exports.ENABLE_URL_COMPLETION_DEFAULT = false;
+const TITLE_REGEX = `(?: +"[^"]+")?`;
+const REPOSITORY_URL = `${process.env['GITHUB_SERVER_URL']}/${process.env['GITHUB_REPOSITORY']}`;
+const BLOB_PREFIX = `${REPOSITORY_URL}/blob/${process.env['GITHUB_REF_NAME']}/`;
+const RAW_PREFIX = `${REPOSITORY_URL}/raw/${process.env['GITHUB_REF_NAME']}/`;
+const MAX_BYTES = 25000;
+function getReadmeContent(readmeFilepath, enableUrlCompletion, imageExtensions) {
+    return __awaiter(this, void 0, void 0, function* () {
+        // Fetch the readme content
+        let readmeContent = yield fs.promises.readFile(readmeFilepath, {
+            encoding: 'utf8'
+        });
+        readmeContent = completeRelativeUrls(readmeContent, readmeFilepath, enableUrlCompletion, imageExtensions);
+        const truncatedReadmeContent = utils.truncateToBytes(readmeContent, MAX_BYTES);
+        if (truncatedReadmeContent.length !== readmeContent.length) {
+            core.warning(`The README content exceeds DockerHub's limit and has been truncated to ${MAX_BYTES} bytes.`);
+        }
+        return truncatedReadmeContent;
+    });
+}
+exports.getReadmeContent = getReadmeContent;
+function completeRelativeUrls(readmeContent, readmeFilepath, enableUrlCompletion, imageExtensions) {
+    if (enableUrlCompletion) {
+        readmeFilepath = readmeFilepath.replace(/^[.][/]/, '');
+        // Make relative urls absolute
+        const rules = [
+            ...getRelativeReadmeAnchorsRules(readmeFilepath),
+            ...getRelativeImageUrlRules(imageExtensions),
+            ...getRelativeUrlRules()
+        ];
+        readmeContent = applyRules(rules, readmeContent);
+    }
+    return readmeContent;
+}
+exports.completeRelativeUrls = completeRelativeUrls;
+function applyRules(rules, readmeContent) {
+    rules.forEach(rule => {
+        const combinedRegex = `${rule.left.source}[(]${rule.url.source}[)]`;
+        core.debug(`rule: ${combinedRegex}`);
+        const replacement = `$<left>(${rule.absUrlPrefix}$<url>)`;
+        core.debug(`replacement: ${replacement}`);
+        readmeContent = readmeContent.replace(new RegExp(combinedRegex, 'giu'), replacement);
+    });
+    return readmeContent;
+}
+// has to be applied first to avoid wrong results
+function getRelativeReadmeAnchorsRules(readmeFilepath) {
+    const prefix = `${BLOB_PREFIX}${readmeFilepath}`;
+    // matches e.g.:
+    //    #table-of-content
+    //    #table-of-content "the anchor (a title)"
+    const url = new RegExp(`(?<url>#[^)]+${TITLE_REGEX})`);
+    const rules = [
+        // matches e.g.:
+        //    [#table-of-content](#table-of-content)
+        //    [#table-of-content](#table-of-content "the anchor (a title)")
+        {
+            left: /(?<left>\[[^\]]+\])/,
+            url: url,
+            absUrlPrefix: prefix
+        },
+        // matches e.g.:
+        //    [![media/image.svg](media/image.svg)](#table-of-content)
+        //    [![media/image.svg](media/image.svg "title a")](#table-of-content "title b")
+        {
+            left: /(?<left>\[!\[[^\]]*\]\([^)]+\)\])/,
+            url: url,
+            absUrlPrefix: prefix
+        }
+    ];
+    return rules;
+}
+function getRelativeImageUrlRules(imageExtensions) {
+    const extensionsRegex = imageExtensions.replace(/,/g, '|');
+    // matches e.g.:
+    //    media/image.svg
+    //    media/image.svg "with title"
+    const url = new RegExp(`(?<url>[^:)]+[.](?:${extensionsRegex})${TITLE_REGEX})`);
+    const rules = [
+        // matches e.g.:
+        //    ![media/image.svg](media/image.svg)
+        //    ![media/image.svg](media/image.svg "with title")
+        {
+            left: /(?<left>!\[[^\]]*\])/,
+            url: url,
+            absUrlPrefix: RAW_PREFIX
+        }
+    ];
+    return rules;
+}
+function getRelativeUrlRules() {
+    // matches e.g.:
+    //    .releaserc.yaml
+    //    README.md#table-of-content "title b"
+    //    .releaserc.yaml "the .releaserc.yaml file (a title)"
+    const url = new RegExp(`(?<url>[^:)]+${TITLE_REGEX})`);
+    const rules = [
+        // matches e.g.:
+        //    [.releaserc.yaml](.releaserc.yaml)
+        //    [.releaserc.yaml](.releaserc.yaml "the .releaserc.yaml file (a title)")
+        {
+            left: /(?<left>\[[^\]]+\])/,
+            url: url,
+            absUrlPrefix: BLOB_PREFIX
+        },
+        // matches e.g.:
+        //    [![media/image.svg](media/image.svg)](media/image.svg)
+        //    [![media/image.svg](media/image.svg)](README.md#table-of-content "title b")
+        //    [![media/image.svg](media/image.svg "title a")](media/image.svg)
+        //    [![media/image.svg](media/image.svg "title a")](media/image.svg "title b")
+        //    [![media/image.svg](media/image.svg "title a")](README.md#table-of-content "title b")
+        {
+            left: new RegExp(`(?<left>\\[!\\[[^\\]]*\\]\\([^)]+${TITLE_REGEX}\\)\\])`),
+            url: url,
+            absUrlPrefix: BLOB_PREFIX
+        }
+    ];
+    return rules;
+}
+
+
+/***/ }),
+
+/***/ 918:
+/***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
+
+"use strict";
+
+Object.defineProperty(exports, "__esModule", ({ value: true }));
+exports.truncateToBytes = exports.getErrorMessage = void 0;
+const unicodeSubstring = __nccwpck_require__(6986);
+function getErrorMessage(error) {
+    if (error instanceof Error)
+        return error.message;
+    return String(error);
+}
+exports.getErrorMessage = getErrorMessage;
+function truncateToBytes(s, n) {
+    let len = n;
+    while (Buffer.byteLength(s) > n) {
+        s = unicodeSubstring(s, 0, len--);
+    }
+    return s;
+}
+exports.truncateToBytes = truncateToBytes;
+
+
 /***/ }),
 
 /***/ 7351:
@@ -3430,6 +3651,20 @@ const isDomainOrSubdomain = function isDomainOrSubdomain(destination, original)
 	return orig === dest || orig[orig.length - dest.length - 1] === '.' && orig.endsWith(dest);
 };
 
+/**
+ * isSameProtocol reports whether the two provided URLs use the same protocol.
+ *
+ * Both domains must already be in canonical form.
+ * @param {string|URL} original
+ * @param {string|URL} destination
+ */
+const isSameProtocol = function isSameProtocol(destination, original) {
+	const orig = new URL$1(original).protocol;
+	const dest = new URL$1(destination).protocol;
+
+	return orig === dest;
+};
+
 /**
  * Fetch function
  *
@@ -3461,7 +3696,7 @@ function fetch(url, opts) {
 			let error = new AbortError('The user aborted a request.');
 			reject(error);
 			if (request.body && request.body instanceof Stream.Readable) {
-				request.body.destroy(error);
+				destroyStream(request.body, error);
 			}
 			if (!response || !response.body) return;
 			response.body.emit('error', error);
@@ -3502,9 +3737,43 @@ function fetch(url, opts) {
 
 		req.on('error', function (err) {
 			reject(new FetchError(`request to ${request.url} failed, reason: ${err.message}`, 'system', err));
+
+			if (response && response.body) {
+				destroyStream(response.body, err);
+			}
+
 			finalize();
 		});
 
+		fixResponseChunkedTransferBadEnding(req, function (err) {
+			if (signal && signal.aborted) {
+				return;
+			}
+
+			if (response && response.body) {
+				destroyStream(response.body, err);
+			}
+		});
+
+		/* c8 ignore next 18 */
+		if (parseInt(process.version.substring(1)) < 14) {
+			// Before Node.js 14, pipeline() does not fully support async iterators and does not always
+			// properly handle when the socket close/end events are out of order.
+			req.on('socket', function (s) {
+				s.addListener('close', function (hadError) {
+					// if a data listener is still present we didn't end cleanly
+					const hasDataListener = s.listenerCount('data') > 0;
+
+					// if end happened before close but the socket didn't emit an error, do it now
+					if (response && hasDataListener && !hadError && !(signal && signal.aborted)) {
+						const err = new Error('Premature close');
+						err.code = 'ERR_STREAM_PREMATURE_CLOSE';
+						response.body.emit('error', err);
+					}
+				});
+			});
+		}
+
 		req.on('response', function (res) {
 			clearTimeout(reqTimeout);
 
@@ -3576,7 +3845,7 @@ function fetch(url, opts) {
 							size: request.size
 						};
 
-						if (!isDomainOrSubdomain(request.url, locationURL)) {
+						if (!isDomainOrSubdomain(request.url, locationURL) || !isSameProtocol(request.url, locationURL)) {
 							for (const name of ['authorization', 'www-authenticate', 'cookie', 'cookie2']) {
 								requestOpts.headers.delete(name);
 							}
@@ -3669,6 +3938,13 @@ function fetch(url, opts) {
 					response = new Response(body, response_options);
 					resolve(response);
 				});
+				raw.on('end', function () {
+					// some old IIS servers return zero-length OK deflate responses, so 'data' is never emitted.
+					if (!response) {
+						response = new Response(body, response_options);
+						resolve(response);
+					}
+				});
 				return;
 			}
 
@@ -3688,6 +3964,41 @@ function fetch(url, opts) {
 		writeToStream(req, request);
 	});
 }
+function fixResponseChunkedTransferBadEnding(request, errorCallback) {
+	let socket;
+
+	request.on('socket', function (s) {
+		socket = s;
+	});
+
+	request.on('response', function (response) {
+		const headers = response.headers;
+
+		if (headers['transfer-encoding'] === 'chunked' && !headers['content-length']) {
+			response.once('close', function (hadError) {
+				// if a data listener is still present we didn't end cleanly
+				const hasDataListener = socket.listenerCount('data') > 0;
+
+				if (hasDataListener && !hadError) {
+					const err = new Error('Premature close');
+					err.code = 'ERR_STREAM_PREMATURE_CLOSE';
+					errorCallback(err);
+				}
+			});
+		}
+	});
+}
+
+function destroyStream(stream, err) {
+	if (stream.destroy) {
+		stream.destroy(err);
+	} else {
+		// node < 8
+		stream.emit('error', err);
+		stream.end();
+	}
+}
+
 /**
  * Redirect code matching
  *
@@ -6152,6 +6463,64 @@ if (process.env.NODE_DEBUG && /\btunnel\b/.test(process.env.NODE_DEBUG)) {
 exports.debug = debug; // for test
 
 
+/***/ }),
+
+/***/ 6986:
+/***/ ((module) => {
+
+"use strict";
+
+
+function charAt(string, index) {
+  var first = string.charCodeAt(index);
+  var second;
+  if (first >= 55296 && first <= 56319 && string.length > index + 1) {
+    second = string.charCodeAt(index + 1);
+    if (second >= 56320 && second <= 57343) {
+      return string.substring(index, index + 2);
+    }
+  }
+  return string[index];
+}
+
+function slice(string, start, end) {
+  var accumulator = "";
+  var character;
+  var stringIndex = 0;
+  var unicodeIndex = 0;
+  var length = string.length;
+
+  while (stringIndex < length) {
+    character = charAt(string, stringIndex);
+    if (unicodeIndex >= start && unicodeIndex < end) {
+      accumulator += character;
+    }
+    stringIndex += character.length;
+    unicodeIndex += 1;
+  }
+  return accumulator;
+}
+
+function toNumber(value, fallback) {
+  if (value === undefined) {
+    return fallback;
+  } else {
+    return Number(value);
+  }
+}
+
+module.exports = function (string, start, end) {
+  var realStart = toNumber(start, 0);
+  var realEnd = toNumber(end, string.length);
+  if (realEnd == realStart) {
+    return "";
+  } else if (realEnd > realStart) {
+    return slice(string, realStart, realEnd);
+  } else {
+    return slice(string, realEnd, realStart);
+  }
+};
+
 /***/ }),
 
 /***/ 5840:

jest.config.js

@@ -9,3 +9,8 @@ module.exports = {
   },
   verbose: true
 }
+process.env = Object.assign(process.env, {
+  GITHUB_SERVER_URL: 'https://github.com',
+  GITHUB_REPOSITORY: 'peter-evans/dockerhub-description',
+  GITHUB_REF_NAME: 'main'
+})

package.json

@@ -9,7 +9,7 @@
     "format": "prettier --write '**/*.ts'",
     "format-check": "prettier --check '**/*.ts'",
     "lint": "eslint src/**/*.ts",
-    "test": "jest --passWithNoTests"
+    "test": "jest"
   },
   "repository": {
     "type": "git",
@@ -28,21 +28,22 @@
   "homepage": "https://github.com/peter-evans/dockerhub-description#readme",
   "dependencies": {
     "@actions/core": "^1.10.0",
-    "node-fetch": "^2.6.7"
+    "node-fetch": "^2.6.9",
+    "unicode-substring": "^0.1.0"
   },
   "devDependencies": {
     "@types/jest": "^27.0.3",
-    "@types/node": "^16.11.11",
-    "@typescript-eslint/parser": "^5.5.0",
-    "@vercel/ncc": "^0.32.0",
-    "eslint": "^8.3.0",
-    "eslint-plugin-github": "^4.3.5",
-    "eslint-plugin-jest": "^25.3.0",
-    "jest": "^27.4.3",
-    "jest-circus": "^27.4.2",
+    "@types/node": "^16.18.23",
+    "@typescript-eslint/parser": "^5.57.0",
+    "@vercel/ncc": "^0.36.1",
+    "eslint": "^8.37.0",
+    "eslint-plugin-github": "^4.7.0",
+    "eslint-plugin-jest": "^25.7.0",
+    "jest": "^27.5.1",
+    "jest-circus": "^27.5.1",
     "js-yaml": "^4.1.0",
-    "prettier": "^2.5.0",
-    "ts-jest": "^27.0.7",
-    "typescript": "^4.5.2"
+    "prettier": "^2.8.7",
+    "ts-jest": "^27.1.5",
+    "typescript": "^4.9.5"
   }
 }

src/dockerhub-helper.ts

@@ -1,8 +1,6 @@
 import * as core from '@actions/core'
 import * as fetch from 'node-fetch'
 
-const DESCRIPTION_MAX_CHARS = 100
-
 export async function getToken(
   username: string,
   password: string
@@ -36,7 +34,7 @@ export async function updateRepositoryDescription(
     full_description: fullDescription
   }
   if (description) {
-    body['description'] = description.slice(0, DESCRIPTION_MAX_CHARS)
+    body['description'] = description
   }
   await fetch(`https://hub.docker.com/v2/repositories/${repository}`, {
     method: 'patch',

src/input-helper.ts

@@ -1,6 +1,5 @@
 import * as core from '@actions/core'
-
-const README_FILEPATH_DEFAULT = './README.md'
+import * as readmeHelper from './readme-helper'
 
 interface Inputs {
   username: string
@@ -8,6 +7,8 @@ interface Inputs {
   repository: string
   shortDescription: string
   readmeFilepath: string
+  enableUrlCompletion: boolean
+  imageExtensions: string
 }
 
 export function getInputs(): Inputs {
@@ -16,7 +17,9 @@ export function getInputs(): Inputs {
     password: core.getInput('password'),
     repository: core.getInput('repository'),
     shortDescription: core.getInput('short-description'),
-    readmeFilepath: core.getInput('readme-filepath')
+    readmeFilepath: core.getInput('readme-filepath'),
+    enableUrlCompletion: Boolean(core.getInput('enable-url-completion')),
+    imageExtensions: core.getInput('image-extensions')
   }
 
   // Environment variable input alternatives and their aliases
@@ -50,16 +53,31 @@ export function getInputs(): Inputs {
     inputs.readmeFilepath = process.env['README_FILEPATH']
   }
 
+  if (!inputs.enableUrlCompletion && process.env['ENABLE_URL_COMPLETION']) {
+    inputs.enableUrlCompletion = Boolean(process.env['ENABLE_URL_COMPLETION'])
+  }
+
+  if (!inputs.imageExtensions && process.env['IMAGE_EXTENSIONS']) {
+    inputs.imageExtensions = process.env['IMAGE_EXTENSIONS']
+  }
+
   // Set defaults
   if (!inputs.readmeFilepath) {
-    inputs.readmeFilepath = README_FILEPATH_DEFAULT
+    inputs.readmeFilepath = readmeHelper.README_FILEPATH_DEFAULT
+  }
+  if (!inputs.enableUrlCompletion) {
+    inputs.enableUrlCompletion = readmeHelper.ENABLE_URL_COMPLETION_DEFAULT
+  }
+  if (!inputs.imageExtensions) {
+    inputs.imageExtensions = readmeHelper.IMAGE_EXTENSIONS_DEFAULT
   }
   if (!inputs.repository && process.env['GITHUB_REPOSITORY']) {
     inputs.repository = process.env['GITHUB_REPOSITORY']
   }
 
-  // Docker repositories must be all lower case
+  // Enforce lower case, where needed
   inputs.repository = inputs.repository.toLowerCase()
+  inputs.imageExtensions = inputs.imageExtensions.toLowerCase()
 
   return inputs
 }

src/main.ts

@@ -1,13 +1,11 @@
 import * as core from '@actions/core'
 import * as inputHelper from './input-helper'
 import * as dockerhubHelper from './dockerhub-helper'
-import * as fs from 'fs'
+import * as readmeHelper from './readme-helper'
+import * as utils from './utils'
 import {inspect} from 'util'
 
-function getErrorMessage(error: unknown) {
-  if (error instanceof Error) return error.message
-  return String(error)
-}
+const SHORT_DESCRIPTION_MAX_BYTES = 100
 
 async function run(): Promise<void> {
   try {
@@ -17,9 +15,24 @@ async function run(): Promise<void> {
     inputHelper.validateInputs(inputs)
 
     // Fetch the readme content
-    const readmeContent = await fs.promises.readFile(inputs.readmeFilepath, {
-      encoding: 'utf8'
-    })
+    core.info('Reading description source file')
+    const readmeContent = await readmeHelper.getReadmeContent(
+      inputs.readmeFilepath,
+      inputs.enableUrlCompletion,
+      inputs.imageExtensions
+    )
+    core.debug(readmeContent)
+
+    // Truncate the short description if it is too long
+    const truncatedShortDescription = utils.truncateToBytes(
+      inputs.shortDescription,
+      SHORT_DESCRIPTION_MAX_BYTES
+    )
+    if (truncatedShortDescription.length !== inputs.shortDescription.length) {
+      core.warning(
+        `The short description exceeds DockerHub's limit and has been truncated to ${SHORT_DESCRIPTION_MAX_BYTES} bytes.`
+      )
+    }
 
     // Acquire a token for the Docker Hub API
     core.info('Acquiring token')
@@ -38,7 +51,7 @@ async function run(): Promise<void> {
     core.info('Request successful')
   } catch (error) {
     core.debug(inspect(error))
-    core.setFailed(getErrorMessage(error))
+    core.setFailed(utils.getErrorMessage(error))
   }
 }
 

src/readme-helper.ts

@@ -0,0 +1,185 @@
+import * as core from '@actions/core'
+import * as fs from 'fs'
+import * as utils from './utils'
+
+export const README_FILEPATH_DEFAULT = './README.md'
+export const IMAGE_EXTENSIONS_DEFAULT = 'bmp,gif,jpg,jpeg,png,svg,webp'
+export const ENABLE_URL_COMPLETION_DEFAULT = false
+
+const TITLE_REGEX = `(?: +"[^"]+")?`
+const REPOSITORY_URL = `${process.env['GITHUB_SERVER_URL']}/${process.env['GITHUB_REPOSITORY']}`
+const BLOB_PREFIX = `${REPOSITORY_URL}/blob/${process.env['GITHUB_REF_NAME']}/`
+const RAW_PREFIX = `${REPOSITORY_URL}/raw/${process.env['GITHUB_REF_NAME']}/`
+
+const MAX_BYTES = 25000
+
+type Rule = {
+  /**
+   * all left of the relative url belonging to the markdown image/link
+   */
+  left: RegExp
+  /**
+   * relative url
+   */
+  url: RegExp
+  /**
+   * part to prefix the relative url with (excluding github repository url)
+   */
+  absUrlPrefix: string
+}
+
+export async function getReadmeContent(
+  readmeFilepath: string,
+  enableUrlCompletion: boolean,
+  imageExtensions: string
+): Promise<string> {
+  // Fetch the readme content
+  let readmeContent = await fs.promises.readFile(readmeFilepath, {
+    encoding: 'utf8'
+  })
+
+  readmeContent = completeRelativeUrls(
+    readmeContent,
+    readmeFilepath,
+    enableUrlCompletion,
+    imageExtensions
+  )
+
+  const truncatedReadmeContent = utils.truncateToBytes(readmeContent, MAX_BYTES)
+  if (truncatedReadmeContent.length !== readmeContent.length) {
+    core.warning(
+      `The README content exceeds DockerHub's limit and has been truncated to ${MAX_BYTES} bytes.`
+    )
+  }
+
+  return truncatedReadmeContent
+}
+
+export function completeRelativeUrls(
+  readmeContent: string,
+  readmeFilepath: string,
+  enableUrlCompletion: boolean,
+  imageExtensions: string
+): string {
+  if (enableUrlCompletion) {
+    readmeFilepath = readmeFilepath.replace(/^[.][/]/, '')
+
+    // Make relative urls absolute
+    const rules = [
+      ...getRelativeReadmeAnchorsRules(readmeFilepath),
+      ...getRelativeImageUrlRules(imageExtensions),
+      ...getRelativeUrlRules()
+    ]
+
+    readmeContent = applyRules(rules, readmeContent)
+  }
+
+  return readmeContent
+}
+
+function applyRules(rules: Rule[], readmeContent: string): string {
+  rules.forEach(rule => {
+    const combinedRegex = `${rule.left.source}[(]${rule.url.source}[)]`
+    core.debug(`rule: ${combinedRegex}`)
+
+    const replacement = `$<left>(${rule.absUrlPrefix}$<url>)`
+    core.debug(`replacement: ${replacement}`)
+
+    readmeContent = readmeContent.replace(
+      new RegExp(combinedRegex, 'giu'),
+      replacement
+    )
+  })
+
+  return readmeContent
+}
+
+// has to be applied first to avoid wrong results
+function getRelativeReadmeAnchorsRules(readmeFilepath: string): Rule[] {
+  const prefix = `${BLOB_PREFIX}${readmeFilepath}`
+
+  // matches e.g.:
+  //    #table-of-content
+  //    #table-of-content "the anchor (a title)"
+  const url = new RegExp(`(?<url>#[^)]+${TITLE_REGEX})`)
+
+  const rules: Rule[] = [
+    // matches e.g.:
+    //    [#table-of-content](#table-of-content)
+    //    [#table-of-content](#table-of-content "the anchor (a title)")
+    {
+      left: /(?<left>\[[^\]]+\])/,
+      url: url,
+      absUrlPrefix: prefix
+    },
+
+    // matches e.g.:
+    //    [![media/image.svg](media/image.svg)](#table-of-content)
+    //    [![media/image.svg](media/image.svg "title a")](#table-of-content "title b")
+    {
+      left: /(?<left>\[!\[[^\]]*\]\([^)]+\)\])/,
+      url: url,
+      absUrlPrefix: prefix
+    }
+  ]
+
+  return rules
+}
+
+function getRelativeImageUrlRules(imageExtensions: string): Rule[] {
+  const extensionsRegex = imageExtensions.replace(/,/g, '|')
+  // matches e.g.:
+  //    media/image.svg
+  //    media/image.svg "with title"
+  const url = new RegExp(
+    `(?<url>[^:)]+[.](?:${extensionsRegex})${TITLE_REGEX})`
+  )
+
+  const rules: Rule[] = [
+    // matches e.g.:
+    //    ![media/image.svg](media/image.svg)
+    //    ![media/image.svg](media/image.svg "with title")
+    {
+      left: /(?<left>!\[[^\]]*\])/,
+      url: url,
+      absUrlPrefix: RAW_PREFIX
+    }
+  ]
+
+  return rules
+}
+
+function getRelativeUrlRules(): Rule[] {
+  // matches e.g.:
+  //    .releaserc.yaml
+  //    README.md#table-of-content "title b"
+  //    .releaserc.yaml "the .releaserc.yaml file (a title)"
+  const url = new RegExp(`(?<url>[^:)]+${TITLE_REGEX})`)
+
+  const rules: Rule[] = [
+    // matches e.g.:
+    //    [.releaserc.yaml](.releaserc.yaml)
+    //    [.releaserc.yaml](.releaserc.yaml "the .releaserc.yaml file (a title)")
+    {
+      left: /(?<left>\[[^\]]+\])/,
+      url: url,
+      absUrlPrefix: BLOB_PREFIX
+    },
+
+    // matches e.g.:
+    //    [![media/image.svg](media/image.svg)](media/image.svg)
+    //    [![media/image.svg](media/image.svg)](README.md#table-of-content "title b")
+    //    [![media/image.svg](media/image.svg "title a")](media/image.svg)
+    //    [![media/image.svg](media/image.svg "title a")](media/image.svg "title b")
+    //    [![media/image.svg](media/image.svg "title a")](README.md#table-of-content "title b")
+    {
+      left: new RegExp(
+        `(?<left>\\[!\\[[^\\]]*\\]\\([^)]+${TITLE_REGEX}\\)\\])`
+      ),
+      url: url,
+      absUrlPrefix: BLOB_PREFIX
+    }
+  ]
+
+  return rules
+}

src/utils.ts

@@ -0,0 +1,14 @@
+import unicodeSubstring = require('unicode-substring')
+
+export function getErrorMessage(error: unknown) {
+  if (error instanceof Error) return error.message
+  return String(error)
+}
+
+export function truncateToBytes(s: string, n: number): string {
+  let len = n
+  while (Buffer.byteLength(s) > n) {
+    s = unicodeSubstring(s, 0, len--)
+  }
+  return s
+}