chore(cli): validate links with trailing slashes (#5652)

* remove trailing

* add entries

* new version

fern/pages/changelogs/cli/2025-01-19.mdx

@@ -1,3 +1,6 @@
+## 0.50.10
+**`(fix):`** An addition to the broken link checker to further reduce false positives.
+
 ## 0.50.9
 **`(fix):`** The Fern CLI no longer logs the full API request when finishing docs registration, 
 reducing unnecessary log output.

packages/cli/cli/versions.yml

@@ -1,3 +1,10 @@
+- changelogEntry:
+    - summary: |
+        An addition to the broken link checker to further reduce false positives.
+      type: fix
+  irVersion: 55
+  version: 0.50.10
+
 - changelogEntry:
     - summary: |
         The Fern CLI no longer logs the full API request when finishing docs registration, 

packages/cli/yaml/docs-validator/src/rules/valid-markdown-link/check-if-pathname-exists.ts

@@ -2,7 +2,7 @@ import { wrapWithHttps } from "@fern-api/docs-resolver";
 import { AbsoluteFilePath, RelativeFilePath, dirname, doesPathExist, join } from "@fern-api/fs-utils";
 
 import { getRedirectForPath } from "./redirect-for-path";
-import { addLeadingSlash, removeLeadingSlash } from "./url-utils";
+import { addLeadingSlash, removeLeadingSlash, removeTrailingSlash } from "./url-utils";
 
 /**
  * Checks if the given path exists in the docs.
@@ -40,6 +40,7 @@ export async function checkIfPathnameExists({
         basePath?: string;
     };
 }): Promise<true | string[]> {
+    pathname = removeTrailingSlash(pathname);
     const slugs = absoluteFilepath != null ? (absoluteFilePathsToSlugs.get(absoluteFilepath) ?? []) : [];
 
     // base case: empty pathname is valid