feat: add BENCHMARK_FETCH_FAILED TierType

README.md

@@ -56,6 +56,19 @@ const gpuTier = await getGPUTier();
 
 Based on the reported `fps` the GPU is then classified into either `tier: 1 (>= 15 fps)`, `tier: 2 (>= 30 fps)` or `tier: 3 (>= 60 fps)`. The higher the tier the more graphically intensive workload you can offer to the user.
 
+## Result types
+
+`getGPUTier()` returns a `type` field indicating how the result was produced:
+
+| `type`                   | Meaning                                                                             |
+| ------------------------ | ----------------------------------------------------------------------------------- |
+| `BENCHMARK`              | Matched a benchmark entry; `fps` reflects the measured framerate for that GPU.      |
+| `FALLBACK`               | Renderer recognised but no benchmark match found. `tier` is a conservative default. |
+| `BENCHMARK_FETCH_FAILED` | Benchmark fetch failed (CDN outage, strict CSP, offline, etc.). Safe to retry.      |
+| `BLOCKLISTED`            | Renderer is on a known-bad list (drivers with severe issues). `tier` is always 0.   |
+| `WEBGL_UNSUPPORTED`      | No WebGL context could be created. `tier` is always 0.                              |
+| `SSR`                    | Running server-side — no `window`, detection skipped.                               |
+
 ## API
 
 ```ts

src/index.ts

@@ -77,7 +77,8 @@ export type TierType =
   | 'WEBGL_UNSUPPORTED'
   | 'BLOCKLISTED'
   | 'FALLBACK'
-  | 'BENCHMARK';
+  | 'BENCHMARK'
+  | 'BENCHMARK_FETCH_FAILED';
 
 export type TierResult = {
   tier: number;
@@ -103,6 +104,11 @@ export const getGPUTier = async ({
   benchmarksURL = `https://unpkg.com/@pmndrs/detect-gpu@${version}/dist/benchmarks`,
 }: GetGPUTier = {}): Promise<TierResult> => {
   const queryCache: { [k: string]: Promise<ModelEntry[]> } = {};
+  // Set when any loadBenchmarks() call rejects with a non-OutdatedBenchmarksError
+  // (e.g. network failure, CORS, CSP blocking unpkg). Consulted only when the
+  // benchmark result list is empty, so a successful renderer match trumps a
+  // failed sibling fetch on a different benchmark file.
+  let benchmarkFetchFailed = false;
   if (isSSR) {
     return {
       tier: 0,
@@ -178,6 +184,7 @@ export const getGPUTier = async ({
       if (error instanceof OutdatedBenchmarksError) {
         throw error;
       }
+      benchmarkFetchFailed = true;
       debug?.("queryBenchmarks - couldn't load benchmark:", { error });
       return;
     }
@@ -318,6 +325,18 @@ export const getGPUTier = async ({
     );
     if (blocklistedModel) return toResult(0, 'BLOCKLISTED', blocklistedModel);
 
+    // Distinguish "couldn't reach the benchmark CDN" from "GPU is genuinely
+    // unknown". Silent tier-1 FALLBACK misrepresents fast hardware as slow
+    // whenever a network/CSP/CORS issue blocks the benchmarks fetch; this
+    // branch lets consumers detect the condition and retry.
+    if (benchmarkFetchFailed) {
+      return toResult(
+        1,
+        'BENCHMARK_FETCH_FAILED',
+        `${renderer} (${rawRenderer})`
+      );
+    }
+
     // Apple Silicon on desktop Safari: the renderer string is the generic
     // "Apple GPU" and Safari reports identical WebGL capabilities across
     // M1–M5 (verified empirically on M1 Max / M2 / M4), so no web-facing

test/index.test.ts

@@ -37,6 +37,7 @@ for (const renderers of [RENDERER_MOBILE, RENDERER_TABLET, RENDERER_DESKTOP]) {
         'BLOCKLISTED',
         'FALLBACK',
         'BENCHMARK',
+        'BENCHMARK_FETCH_FAILED',
       ]).toContain(type);
     });
   }
@@ -339,6 +340,22 @@ test('Apple Silicon desktop Safari — conservative tier-3 FALLBACK', async () =
   expect(result.fps).toBe(60);
 });
 
+test('benchmark fetch failure surfaces as BENCHMARK_FETCH_FAILED, not silent FALLBACK', async () => {
+  // Silent degradation to tier-1 FALLBACK misrepresents fast hardware as
+  // slow whenever the benchmark CDN is blocked (CSP, CORS, unpkg outage).
+  // Consumers need a way to detect the condition so they can retry.
+  const result = await getTier({
+    isMobile: false,
+    renderer:
+      'ANGLE (NVIDIA, NVIDIA GeForce RTX 3060 Laptop GPU (0x00002520) Direct3D11 vs_5_0 ps_5_0, D3D11)',
+    loadBenchmarks: async () => {
+      throw new Error('simulated network failure');
+    },
+  });
+  expect(result.type).toBe('BENCHMARK_FETCH_FAILED');
+  expect(result.tier).toBe(1);
+});
+
 test('Apple GPU on mobile does NOT take the desktop tier-3 path', async () => {
   // iPhone/iPad route through deobfuscateAppleGPU and resolve to specific
   // chip benchmarks. The desktop tier-3 fallback must not fire on mobile,
@@ -417,11 +434,11 @@ test('Apple GPU on mobile does NOT take the desktop tier-3 path', async () => {
   });
 });
 
-test(`When queryBenchmarks throws, FALLBACK is returned`, async () => {
+test(`When queryBenchmarks throws, BENCHMARK_FETCH_FAILED is returned`, async () => {
   expectGPUResults(
     {
       tier: 1,
-      type: 'FALLBACK',
+      type: 'BENCHMARK_FETCH_FAILED',
     },
     await getTier({
       loadBenchmarks: async (): Promise<ModelEntry[]> => {