JustinBeckwith · JustinBeckwith · Nov 20, 2019 · Nov 19, 2019 · Nov 19, 2019 · Nov 19, 2019
diff --git a/README.md b/README.md
@@ -127,7 +127,7 @@ Asynchronous method that runs a site wide scan. Options come in the form of an o
 - `concurrency` (number) - The number of connections to make simultaneously. Defaults to 100.
 - `port` (number) - When the `path` is provided as a local path on disk, the `port` on which to start the temporary web server. Defaults to a random high range order port.
 - `recurse` (boolean) - By default, all scans are shallow. Only the top level links on the requested page will be scanned. By setting `recurse` to `true`, the crawler will follow all links on the page, and continue scanning links **on the same domain** for as long as it can go. Results are cached, so no worries about loops.
-- `linksToSkip` (array) - An array of regular expression strings that should be skipped during the scan.
+- `linksToSkip` (array | function) - An array of regular expression strings that should be skipped, OR an async function that's called for each link with the link URL as its only argument. Return a Promise that resolves to `true` to skip the link or `false` to check it.
 
 #### linkinator.LinkChecker()
 Constructor method that can be used to create a new `LinkChecker` instance. This is particularly useful if you want to receive events as the crawler crawls. Exposes the following events:

diff --git a/src/index.ts b/src/index.ts
@@ -16,7 +16,7 @@ export interface CheckOptions {
  port?: number;
  path: string;
  recurse?: boolean;
- linksToSkip?: string[];
+ linksToSkip?: string[] | ((link: string) => Promise<boolean>);
 }
 
 export enum LinkState {
@@ -137,14 +137,11 @@ export class LinkChecker extends EventEmitter {
  return;
  }
 
- // Check for user configured links that should be skipped
- const skips = opts.checkOptions
- .linksToSkip!.map(linkToSkip => {
- return new RegExp(linkToSkip).test(opts.url.href);
- })
- .filter(match => !!match);
-
- if (skips.length > 0) {
+ // Check for a user-configured function to filter out links
+ if (
+ typeof opts.checkOptions.linksToSkip === 'function' &&
+ (await opts.checkOptions.linksToSkip(opts.url.href))
+ ) {
  const result: LinkResult = {
  url: opts.url.href,
  state: LinkState.SKIPPED,
@@ -155,6 +152,26 @@ export class LinkChecker extends EventEmitter {
  return;
  }
 
+ // Check for a user-configured array of link regular expressions that should be skipped
+ if (Array.isArray(opts.checkOptions.linksToSkip)) {
+ const skips = opts.checkOptions.linksToSkip
+ .map(linkToSkip => {
+ return new RegExp(linkToSkip).test(opts.url.href);
+ })
+ .filter(match => !!match);
+
+ if (skips.length > 0) {
+ const result: LinkResult = {
+ url: opts.url.href,
+ state: LinkState.SKIPPED,
+ parent: opts.parent,
+ };
+ opts.results.push(result);
+ this.emit('link', result);
+ return;
+ }
+ }
+
  // Perform a HEAD or GET request based on the need to crawl
  let status = 0;
  let state = LinkState.BROKEN;

diff --git a/test/fixtures/filter/index.html b/test/fixtures/filter/index.html
@@ -0,0 +1,7 @@
+<html>
+<body>
+<a href="https://good.com">I'm good</a>
+<a href="http://www.filterme.com">I should be filtered</a>
+<a href="https://example.com/filtermetoo">I should also be filtered</a>
+</body>
+</html>
diff --git a/test/test.ts b/test/test.ts
@@ -45,6 +45,22 @@ describe('linkinator', () => {
  );
  });
 
+ it('should skip links if passed a linksToSkip function', async () => {
+ const scope = nock('https://good.com')
+ .head('/')
+ .reply(200);
+ const results = await check({
+ path: 'test/fixtures/filter',
+ linksToSkip: link => Promise.resolve(link.includes('filterme')),
+ });
+ assert.ok(results.passed);
+ assert.strictEqual(
+ results.links.filter(x => x.state === LinkState.SKIPPED).length,
+ 2
+ );
+ scope.done();
+ });
+
  it('should report broken links', async () => {
  const scope = nock('http://fake.local')
  .head('/')