Add parameter validation

Author: FrederikBolding

packages/snaps-execution-environments/src/common/BaseSnapExecutor.test.browser.ts

@@ -1496,7 +1496,13 @@ describe('BaseSnapExecutor', () => {
         MOCK_SNAP_ID,
         HandlerType.OnAssetsLookup,
         MOCK_ORIGIN,
-        { jsonrpc: '2.0', method: '', params: { assets: [] } },
+        {
+          jsonrpc: '2.0',
+          method: '',
+          params: {
+            assets: ['bip122:000000000019d6689c085ae165831e93/slip44:0'],
+          },
+        },
       ],
     });
 
@@ -1529,7 +1535,18 @@ describe('BaseSnapExecutor', () => {
         MOCK_SNAP_ID,
         HandlerType.OnAssetsConversion,
         MOCK_ORIGIN,
-        { jsonrpc: '2.0', method: '', params: { conversions: [] } },
+        {
+          jsonrpc: '2.0',
+          method: '',
+          params: {
+            conversions: [
+              {
+                from: 'bip122:000000000019d6689c085ae165831e93/slip44:0',
+                to: 'eip155:1/slip44:60',
+              },
+            ],
+          },
+        },
       ],
     });
 

packages/snaps-execution-environments/src/common/commands.ts

@@ -15,6 +15,8 @@ import {
   assertIsOnSignatureRequestArguments,
   assertIsOnNameLookupRequestArguments,
   assertIsOnUserInputRequestArguments,
+  assertIsOnAssetsLookupRequestArguments,
+  assertIsOnAssetsConversionRequestArguments,
 } from './validation';
 
 export type CommandMethodsMapping = {
@@ -57,12 +59,12 @@ export function getHandlerArguments(
       return { signature, signatureOrigin };
     }
     case HandlerType.OnAssetsLookup: {
-      // TODO: Assert once we have structs
+      assertIsOnAssetsLookupRequestArguments(request.params);
       const { assets } = request.params;
       return { assets };
     }
     case HandlerType.OnAssetsConversion: {
-      // TODO: Assert once we have structs
+      assertIsOnAssetsConversionRequestArguments(request.params);
       const { conversions } = request.params;
       return { conversions };
     }

packages/snaps-execution-environments/src/common/validation.ts

@@ -16,13 +16,15 @@ import {
   object,
   optional,
   record,
+  size,
   string,
   tuple,
   union,
 } from '@metamask/superstruct';
 import type { Json, JsonRpcSuccess } from '@metamask/utils';
 import {
   assertStruct,
+  CaipAssetTypeStruct,
   JsonRpcIdStruct,
   JsonRpcParamsStruct,
   JsonRpcSuccessStruct,
@@ -216,6 +218,69 @@ export function assertIsOnNameLookupRequestArguments(
   );
 }
 
+export const OnAssetsLookupRequestArgumentsStruct = object({
+  assets: size(array(CaipAssetTypeStruct), 1, Infinity),
+});
+
+export type OnAssetsLookupRequestArguments = Infer<
+  typeof OnAssetsLookupRequestArgumentsStruct
+>;
+
+/**
+ * Asserts that the given value is a valid {@link OnAssetsLookupRequestArguments}
+ * object.
+ *
+ * @param value - The value to validate.
+ * @throws If the value is not a valid {@link OnAssetsLookupRequestArguments}
+ * object.
+ */
+export function assertIsOnAssetsLookupRequestArguments(
+  value: unknown,
+): asserts value is OnAssetsLookupRequestArguments {
+  assertStruct(
+    value,
+    OnAssetsLookupRequestArgumentsStruct,
+    'Invalid request params',
+    rpcErrors.invalidParams,
+  );
+}
+
+export const OnAssetsConversionRequestArgumentsStruct = object({
+  conversions: size(
+    array(
+      object({
+        from: CaipAssetTypeStruct,
+        to: CaipAssetTypeStruct,
+      }),
+    ),
+    1,
+    Infinity,
+  ),
+});
+
+export type OnAssetsConversionRequestArguments = Infer<
+  typeof OnAssetsConversionRequestArgumentsStruct
+>;
+
+/**
+ * Asserts that the given value is a valid {@link OnAssetsConversionRequestArguments}
+ * object.
+ *
+ * @param value - The value to validate.
+ * @throws If the value is not a valid {@link OnNameLookupRequestArguments}
+ * object.
+ */
+export function assertIsOnAssetsConversionRequestArguments(
+  value: unknown,
+): asserts value is OnAssetsConversionRequestArguments {
+  assertStruct(
+    value,
+    OnAssetsConversionRequestArgumentsStruct,
+    'Invalid request params',
+    rpcErrors.invalidParams,
+  );
+}
+
 export const OnUserInputArgumentsStruct = object({
   id: string(),
   event: UserInputEventStruct,