fix(caniuse): handle wf- prefixed web-features IDs

When a caniuse feature lookup fails with a wf- prefix, strip the prefix and
retry. Returns a clear 404 if no match is found.

Closes #467

Author: marcoscaceres

routes/caniuse/feature.ts

@@ -1,5 +1,4 @@
 import { Request, Response } from "express";
-import { seconds } from "../../utils/misc.js";
 import { BROWSERS, DEFAULT_BROWSERS } from "./lib/constants.js";
 import { Data, getData } from "./lib/index.js";
 
@@ -11,16 +10,18 @@ export default async function route(req: IRequest, res: Response) {
   const { feature } = req.params;
   const browsers = normalizeBrowsers(req.query.browsers);
 
-
   try {
     const data = await getData(feature);
     if (data === null) {
-      res.sendStatus(404);
+      const hint = feature.startsWith("wf-")
+        ? ` The "wf-" prefix indicates a web-features ID. No matching caniuse data was found for "${feature}" or "${feature.slice(3)}".`
+        : "";
+      res.status(404).json({ error: `Feature "${feature}" not found.${hint}` });
       return;
     }
     const result = [];
     for (const browser of browsers) {
-      result.push({ browser, ...getBrowserData(data?.all[browser]) });
+      result.push({ browser, ...getBrowserData(data.all[browser]) });
     }
     res.json({ result });
   } catch (error) {

routes/caniuse/lib/index.ts

@@ -15,6 +15,7 @@ import {
 export { Data };
 
 const DATA_DIR = env("DATA_DIR");
+const CANIUSE_DIR = path.join(DATA_DIR, "caniuse");
 
 interface Options {
   feature: string;
@@ -106,11 +107,20 @@ function sanitizeBrowsersList(browsers?: string | string[]) {
 }
 
 export async function getData(feature: string) {
+  // Try the feature as-is first, then fall back to stripping the "wf-" prefix.
+  // E.g., "wf-css-grid" falls back to looking up "css-grid" in caniuse data.
+  const data = await readFeatureFile(feature);
+  if (data) return data;
+  if (feature.startsWith("wf-")) return readFeatureFile(feature.slice(3));
+  return null;
+}
+
+async function readFeatureFile(feature: string) {
   if (cache.has(feature)) {
     return cache.get(feature) as Data;
   }
   const file = path.format({
-    dir: path.join(DATA_DIR, "caniuse"),
+    dir: CANIUSE_DIR,
     name: `${feature}.json`,
   });
 
@@ -120,7 +130,10 @@ export async function getData(feature: string) {
     cache.set(feature, data);
     return data;
   } catch (error) {
-    console.error(error);
+    const code = (error as NodeJS.ErrnoException).code;
+    if (code !== "ENOENT") {
+      console.error(error);
+    }
     return null;
   }
 }