Refactor selectDeviceOrSkipTest system

The existing system selected the device immediately which means
code like this

    t.selectDeviceOrSkipTest('timestamp-query');
    t.selectDeviceOrSkipTesT('float32-renderable'); // fail!

would fail on the 2nd line because a device had already been
requested on the first line.

Refactored so that the various requirements are merged and
only at the end is a device requested.

Tested here:
greggman@d4abf41

src/webgpu/api/operation/device/all_limits_and_features.spec.ts

@@ -12,6 +12,9 @@ import { CanonicalDeviceDescriptor, DescriptorModifier } from '../../../util/dev
 
 /**
  * Gets the adapter limits as a standard JavaScript object.
+ * MAINTENANCE_TODO: Remove this and use the same function from gpu_test.ts once minSubgroupSize is removed
+ * The reason this is separate now is we want this test to fail. `mnSubgroupSize` should never have
+ * be added and this test exists to see that the same mistake doesn't happen in the future.
  */
 function getAdapterLimitsAsDeviceRequiredLimits(adapter: GPUAdapter) {
   const requiredLimits: Record<string, GPUSize64> = {};
@@ -39,7 +42,7 @@ function setAllLimitsToAdapterLimitsAndAddAllFeatures(
  * Used to request a device with all the max limits of the adapter.
  */
 export class AllLimitsAndFeaturesGPUTestSubcaseBatchState extends GPUTestSubcaseBatchState {
-  override selectDeviceOrSkipTestCase(
+  override requestDeviceWithRequiredParametersOrSkip(
     descriptor: DeviceSelectionDescriptor,
     descriptorModifier?: DescriptorModifier
   ): void {
@@ -54,7 +57,10 @@ export class AllLimitsAndFeaturesGPUTestSubcaseBatchState extends GPUTestSubcase
         return `${baseKey}:AllLimitsAndFeaturesTest`;
       },
     };
-    super.selectDeviceOrSkipTestCase(initUncanonicalizedDeviceDescriptor(descriptor), mod);
+    super.requestDeviceWithRequiredParametersOrSkip(
+      initUncanonicalizedDeviceDescriptor(descriptor),
+      mod
+    );
   }
 }
 

src/webgpu/gpu_test.ts

@@ -92,15 +92,32 @@ export type DeviceSelectionDescriptor =
 
 export function initUncanonicalizedDeviceDescriptor(
   descriptor: DeviceSelectionDescriptor
-): UncanonicalizedDeviceDescriptor | undefined {
+): UncanonicalizedDeviceDescriptor {
   if (typeof descriptor === 'string') {
     return { requiredFeatures: [descriptor] };
   } else if (descriptor instanceof Array) {
     return {
       requiredFeatures: descriptor.filter(f => f !== undefined) as GPUFeatureName[],
     };
   } else {
-    return descriptor;
+    return descriptor ?? {};
+  }
+}
+
+type DeviceDescriptorSimplified = {
+  requiredFeatures: GPUFeatureName[];
+  requiredLimits: Record<string, number>;
+  defaultQueue: GPUQueueDescriptor;
+};
+
+function mergeDeviceSelectionDescriptorIntoDeviceDescriptor(
+  src: DeviceSelectionDescriptor,
+  dst: DeviceDescriptorSimplified
+) {
+  const srcFixed = initUncanonicalizedDeviceDescriptor(src);
+  if (srcFixed) {
+    dst.requiredFeatures.push(...(srcFixed.requiredFeatures ?? []));
+    Object.assign(dst.requiredLimits, srcFixed.requiredLimits ?? {});
   }
 }
 
@@ -109,6 +126,12 @@ export class GPUTestSubcaseBatchState extends SubcaseBatchState {
   private provider: Promise<DeviceProvider> | undefined;
   /** Provider for mismatched device. */
   private mismatchedProvider: Promise<DeviceProvider> | undefined;
+  /** The accumulated skip-if requirements for this subcase */
+  private skipIfRequirements: DeviceDescriptorSimplified = {
+    requiredFeatures: [],
+    requiredLimits: {},
+    defaultQueue: {},
+  };
 
   override async postInit(): Promise<void> {
     // Skip all subcases if there's no device.
@@ -128,7 +151,7 @@ export class GPUTestSubcaseBatchState extends SubcaseBatchState {
   /** @internal MAINTENANCE_TODO: Make this not visible to test code? */
   acquireProvider(): Promise<DeviceProvider> {
     if (this.provider === undefined) {
-      this.selectDeviceOrSkipTestCase(undefined);
+      this.requestDeviceWithRequiredParametersOrSkip(this.skipIfRequirements);
     }
     assert(this.provider !== undefined);
     return this.provider;
@@ -145,7 +168,7 @@ export class GPUTestSubcaseBatchState extends SubcaseBatchState {
    *
    * If the request isn't supported, throws a SkipTestCase exception to skip the entire test case.
    */
-  selectDeviceOrSkipTestCase(
+  requestDeviceWithRequiredParametersOrSkip(
     descriptor: DeviceSelectionDescriptor,
     descriptorModifier?: DescriptorModifier
   ): void {
@@ -159,6 +182,16 @@ export class GPUTestSubcaseBatchState extends SubcaseBatchState {
     this.provider.catch(() => {});
   }
 
+  /**
+   * Some tests or cases need particular feature flags or limits to be enabled.
+   * Call this function with a descriptor or feature name (or `undefined`) to add
+   * features or limits required by the subcase. If the features or limits are not
+   * available a SkipTestCase exception will be thrown to skip the entire test case.
+   */
+  selectDeviceOrSkipTestCase(descriptor: DeviceSelectionDescriptor): void {
+    mergeDeviceSelectionDescriptorIntoDeviceDescriptor(descriptor, this.skipIfRequirements);
+  }
+
   /**
    * Convenience function for {@link selectDeviceOrSkipTestCase}.
    * Select a device with the features required by these texture format(s).
@@ -1310,7 +1343,7 @@ function getAdapterLimitsAsDeviceRequiredLimits(adapter: GPUAdapter) {
  *    t.skipIf(!(limit >= 2)); // Good. Skips if limits is not >= 2. undefined is not >= 2.
  * ```
  */
-function removeNonExistantLimits(adapter: GPUAdapter, limits: Record<string, GPUSize64>) {
+function removeNonExistentLimits(adapter: GPUAdapter, limits: Record<string, GPUSize64>) {
   const filteredLimits: Record<string, GPUSize64> = {};
   const adapterLimits = adapter.limits as unknown as Record<string, GPUSize64>;
   for (const [limit, value] of Object.entries(limits)) {
@@ -1330,7 +1363,7 @@ function applyLimitsToDescriptor(
     requiredFeatures: [],
     defaultQueue: {},
     ...desc,
-    requiredLimits: removeNonExistantLimits(adapter, getRequiredLimits(adapter)),
+    requiredLimits: removeNonExistentLimits(adapter, getRequiredLimits(adapter)),
   };
   return descWithMaxLimits;
 }
@@ -1382,7 +1415,7 @@ export class RequiredLimitsGPUTestSubcaseBatchState extends GPUTestSubcaseBatchS
     super(recorder, params);
     this.requiredLimitsHelper = requiredLimitsHelper;
   }
-  override selectDeviceOrSkipTestCase(
+  override requestDeviceWithRequiredParametersOrSkip(
     descriptor: DeviceSelectionDescriptor,
     descriptorModifier?: DescriptorModifier
   ): void {
@@ -1398,7 +1431,10 @@ export class RequiredLimitsGPUTestSubcaseBatchState extends GPUTestSubcaseBatchS
         return `${baseKey}:${requiredLimitsHelper.key()}`;
       },
     };
-    super.selectDeviceOrSkipTestCase(initUncanonicalizedDeviceDescriptor(descriptor), mod);
+    super.requestDeviceWithRequiredParametersOrSkip(
+      initUncanonicalizedDeviceDescriptor(descriptor),
+      mod
+    );
   }
 }
 

src/webgpu/util/device_pool.ts

@@ -233,14 +233,6 @@ class DescriptorToHolderMap {
 export type UncanonicalizedDeviceDescriptor = {
   requiredFeatures?: Iterable<GPUFeatureName>;
   requiredLimits?: Record<string, GPUSize32>;
-  /** @deprecated this field cannot be used */
-  nonGuaranteedFeatures?: undefined;
-  /** @deprecated this field cannot be used */
-  nonGuaranteedLimits?: undefined;
-  /** @deprecated this field cannot be used */
-  extensions?: undefined;
-  /** @deprecated this field cannot be used */
-  features?: undefined;
 };
 export type CanonicalDeviceDescriptor = Omit<
   Required<GPUDeviceDescriptor>,