docs: add script to catch bad redirects (#12361)

* docs: add script to catch bad redirects

* add missing dependency

www/packages/build-scripts/src/catch-bad-redirects.ts

@@ -0,0 +1,17 @@
+import type { NextConfig } from "next"
+
+type CatchBadRedirectsOptions = Awaited<
+  ReturnType<NonNullable<NextConfig["redirects"]>>
+>
+
+export const catchBadRedirects = (redirects: CatchBadRedirectsOptions) => {
+  for (const redirect of redirects) {
+    if (redirect.source === redirect.destination) {
+      throw new Error(
+        `Redirect source and destination are the same: ${JSON.stringify(redirect, null, 2)}`
+      )
+    }
+  }
+
+  return redirects
+}

www/packages/build-scripts/src/index.ts

@@ -3,6 +3,7 @@ export * from "./generate-llms-full.js"
 export * from "./generate-sidebar.js"
 export * from "./generate-split-sidebars.js"
 export * from "./retrieve-mdx-pages.js"
+export * from "./catch-bad-redirects.js"
 
 export * from "./utils/get-core-flows-ref-sidebar-children.js"
 export * from "./utils/get-sidebar-item-link.js"