feat: Add repository-aware link checking

.github/workflows/pr-link-check.yml

@@ -0,0 +1,27 @@
+name: 'PR Link Check'
+
+on:
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  markdown-link-check:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '18'
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Generate file manifest
+        id: manifest
+        run: git ls-files > file-manifest.txt
+
+      - name: Run markdown-link-check
+        run: ./markdown-link-check --file-manifest file-manifest.txt .

index.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const path = require('path');
 const async = require('async');
 const linkCheck = require('link-check');
 const LinkCheckResult = require('link-check').LinkCheckResult;
@@ -199,6 +200,35 @@ module.exports = function markdownLinkCheck(markdown, opts, callback) {
             return;
         }
 
+        // Check for relative file paths if a file manifest is provided
+        if (opts.projectFiles && opts.sourceFile) {
+            const isAbsoluteUrl = /^[a-zA-Z][a-zA-Z.+-]*:/.test(link);
+
+            if (!isAbsoluteUrl && !link.startsWith('#')) {
+                const sourceDir = path.dirname(opts.sourceFile);
+
+                // The link may have a hash/anchor at the end, which should be ignored for file path resolution
+                const hashIndex = link.indexOf('#');
+                const linkPath = hashIndex === -1 ? link : link.substring(0, hashIndex);
+
+                const resolvedPath = path.resolve(sourceDir, linkPath);
+                const projectRoot = process.cwd();
+                const relativePath = path.relative(projectRoot, resolvedPath);
+
+                // Normalize path separators to handle cross-platform differences
+                const normalizedRelativePath = relativePath.replace(/\\/g, '/');
+                const normalizedProjectFiles = opts.projectFiles.map(p => p.replace(/\\/g, '/'));
+
+                if (normalizedProjectFiles.includes(normalizedRelativePath)) {
+                    // File exists in the project, so we'll treat the link as 'alive'
+                    const result = new LinkCheckResult(opts, link, 200, undefined);
+                    result.status = 'alive';
+                    callback(null, result);
+                    return; // Bypass the external linkCheck
+                }
+            }
+        }
+
         linkCheck(link, opts, function (err, result) {
             if (opts.showProgressBar) {
                 bar.tick();

markdown-link-check

@@ -126,6 +126,7 @@ function getInputs() {
         .option('-a, --alive <code>', 'comma separated list of HTTP codes to be considered as alive', commaSeparatedCodesList)
         .option('-r, --retry', 'retry after the duration indicated in \'retry-after\' header when HTTP code is 429')
         .option('--reporters <names>', 'specify reporters to use', commaSeparatedReportersList)
+        .option('--file-manifest <path>', 'path to a file containing a newline-separated list of project files for relative link validation')
         .option('--projectBaseUrl <url>', 'the URL to use for {{BASEURL}} replacement')
         .arguments('[filenamesOrDirectorynamesOrUrls...]')
         .action(function (filenamesOrUrls) {
@@ -200,16 +201,30 @@ function getInputs() {
                         }
 
                         stream = fs.createReadStream(filenameForOutput);
-                        inputs.push(new Input(filenameForOutput, stream, {baseUrl: baseUrl}));
+                        inputs.push(new Input(filenameForOutput, stream, {baseUrl: baseUrl, sourceFile: resolved}));
                     }
                 }
             }
         }
     ).parse(process.argv);
 
+    const opts = program.opts();
+    let projectFiles = [];
+    if (opts.fileManifest) {
+        try {
+            projectFiles = fs.readFileSync(opts.fileManifest, 'utf8').split('\n').filter(Boolean);
+        } catch (err) {
+            console.error(`\nERROR: Cannot read file manifest '${opts.fileManifest}'`);
+            process.exit(1);
+        }
+    }
+
     for (const input of inputs) {
-        input.opts.showProgressBar = (program.opts().progress === true); // force true or undefined to be true or false.
-        input.opts.quiet = (program.opts().quiet === true);
+        if (projectFiles.length > 0) {
+            input.opts.projectFiles = projectFiles;
+        }
+        input.opts.showProgressBar = (opts.progress === true); // force true or undefined to be true or false.
+        input.opts.quiet = (opts.quiet === true);
         input.opts.verbose = (program.opts().verbose === true);
         input.opts.retryOn429 = (program.opts().retry === true);
         input.opts.aliveStatusCodes = program.opts().alive;

test-manifest.txt

@@ -0,0 +1 @@
+test/project-files-test.md\ntest/another-file.md

test/another-file.md

@@ -0,0 +1,4 @@
+This is another file.
+
+## Section
+Here is the content of the section.

test/markdown-link-check.test.js

@@ -436,4 +436,45 @@ describe('markdown-link-check', function () {
             done();
         });
     });
+
+    describe('project files', function () {
+        it('should pass for local file link when manifest is provided', function (done) {
+            const markdown = fs.readFileSync(path.join(dirname, 'project-files-test.md'), 'utf8');
+            const opts = {
+                projectFiles: [
+                    'test/project-files-test.md',
+                    'test/another-file.md'
+                ],
+                sourceFile: path.resolve(path.join(dirname, 'project-files-test.md'))
+            };
+
+            markdownLinkCheck(markdown, opts, function (err, results) {
+                expect(err).to.be(null);
+                expect(results).to.be.an('array');
+                expect(results).to.have.length(2);
+                expect(results[0].status).to.be('alive');
+                expect(results[0].link).to.be('./another-file.md');
+                expect(results[1].status).to.be('alive');
+                expect(results[1].link).to.be('./another-file.md#section');
+                done();
+            });
+        });
+
+        it('should fail for local file link when manifest is not provided', function (done) {
+            const markdown = fs.readFileSync(path.join(dirname, 'project-files-test.md'), 'utf8');
+            const opts = {
+                baseUrl: 'http://localhost:1234' // Provide a dummy base URL
+            };
+
+            markdownLinkCheck(markdown, opts, function (err, results) {
+                expect(err).to.be(null);
+                expect(results).to.be.an('array');
+                expect(results).to.have.length(2);
+                // Without the manifest, it tries to resolve them as web links and fails
+                expect(results[0].status).to.be('dead');
+                expect(results[1].status).to.be('dead');
+                done();
+            });
+        });
+    });
 });

test/project-files-test.md

@@ -0,0 +1,5 @@
+This file contains a link to another file within the project.
+
+[Link to another file](./another-file.md)
+
+[Link to another file with anchor](./another-file.md#section)