Validate that initial permissions type matches validation struct (#2293)

By using Superstruct's `Describe` type, we can validate that a struct is assignable to a type. In this case, we make sure that the validation struct in `snaps-utils` matches the type in `snaps-sdk`. I had to make a small change to the type to get validation to pass.
MetaMask · Mar 20, 2024 · 3b94315 · 3b94315
1 parent 081b0f7
commit 3b94315
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Showing 4 changed files with 42 additions and 14 deletions.
diff --git a/packages/snaps-sdk/src/types/permissions.ts b/packages/snaps-sdk/src/types/permissions.ts
@@ -9,6 +9,18 @@ export type Cronjob = {
   request: Omit<JsonRpcRequest, 'jsonrpc' | 'id'>;
 };
 
+export type NameLookupMatchers =
+  | {
+      tlds: string[];
+    }
+  | {
+      schemes: string[];
+    }
+  | {
+      tlds: string[];
+      schemes: string[];
+    };
+
 export type Bip32Entropy = {
   curve: 'secp256k1' | 'ed25519';
   path: string[];
@@ -37,7 +49,7 @@ export type InitialPermissions = Partial<{
   };
   'endowment:name-lookup': {
     chains?: ChainId[];
-    matchers?: { tlds?: string[]; schemes?: string[] };
+    matchers?: NameLookupMatchers;
     maxRequestTime?: number;
   };
   'endowment:network-access': EmptyObject;

diff --git a/packages/snaps-utils/coverage.json b/packages/snaps-utils/coverage.json
@@ -2,5 +2,5 @@
   "branches": 96.48,
   "functions": 98.64,
   "lines": 98.74,
-  "statements": 94.51
+  "statements": 94.52
 }
diff --git a/packages/snaps-utils/src/manifest/validation.test.ts b/packages/snaps-utils/src/manifest/validation.test.ts
@@ -6,6 +6,7 @@ import {
   Bip32EntropyStruct,
   Bip32PathStruct,
   createSnapManifest,
+  EmptyObjectStruct,
   isSnapManifest,
   SnapIdsStruct,
 } from './validation';
@@ -152,6 +153,16 @@ describe('SnapIdsStruct', () => {
   });
 });
 
+describe('EmptyObjectStruct', () => {
+  it('accepts an empty object', () => {
+    expect(is({}, EmptyObjectStruct)).toBe(true);
+  });
+
+  it('rejects non-empty objects', () => {
+    expect(is({ foo: 'bar' }, EmptyObjectStruct)).toBe(false);
+  });
+});
+
 describe('isSnapManifest', () => {
   it('returns true for a valid snap manifest', () => {
     expect(isSnapManifest(getSnapManifest())).toBe(true);

diff --git a/packages/snaps-utils/src/manifest/validation.ts b/packages/snaps-utils/src/manifest/validation.ts
@@ -1,5 +1,5 @@
 import { isValidBIP32PathSegment } from '@metamask/key-tree';
-import type { InitialPermissions } from '@metamask/snaps-sdk';
+import type { EmptyObject, InitialPermissions } from '@metamask/snaps-sdk';
 import {
   assertStruct,
   ChecksumStruct,
@@ -8,7 +8,7 @@ import {
   inMilliseconds,
   Duration,
 } from '@metamask/utils';
-import type { Infer, Struct } from 'superstruct';
+import type { Describe, Infer, Struct } from 'superstruct';
 import {
   array,
   boolean,
@@ -175,15 +175,20 @@ export const HandlerCaveatsStruct = object({
 
 export type HandlerCaveats = Infer<typeof HandlerCaveatsStruct>;
 
+export const EmptyObjectStruct = object<EmptyObject>({}) as unknown as Struct<
+  EmptyObject,
+  null
+>;
+
 /* eslint-disable @typescript-eslint/naming-convention */
-export const PermissionsStruct = type({
+export const PermissionsStruct: Describe<InitialPermissions> = type({
   'endowment:cronjob': optional(
     assign(
       HandlerCaveatsStruct,
       object({ jobs: CronjobSpecificationArrayStruct }),
     ),
   ),
-  'endowment:ethereum-provider': optional(object({})),
+  'endowment:ethereum-provider': optional(EmptyObjectStruct),
   'endowment:keyring': optional(
     assign(HandlerCaveatsStruct, KeyringOriginsStruct),
   ),
@@ -197,7 +202,7 @@ export const PermissionsStruct = type({
       }),
     ),
   ),
-  'endowment:network-access': optional(object({})),
+  'endowment:network-access': optional(EmptyObjectStruct),
   'endowment:page-home': optional(HandlerCaveatsStruct),
   'endowment:rpc': optional(assign(HandlerCaveatsStruct, RpcOriginsStruct)),
   'endowment:signature-insight': optional(
@@ -216,11 +221,11 @@ export const PermissionsStruct = type({
       }),
     ),
   ),
-  'endowment:webassembly': optional(object({})),
-  snap_dialog: optional(object({})),
-  snap_manageState: optional(object({})),
-  snap_manageAccounts: optional(object({})),
-  snap_notify: optional(object({})),
+  'endowment:webassembly': optional(EmptyObjectStruct),
+  snap_dialog: optional(EmptyObjectStruct),
+  snap_manageState: optional(EmptyObjectStruct),
+  snap_manageAccounts: optional(EmptyObjectStruct),
+  snap_notify: optional(EmptyObjectStruct),
   snap_getBip32Entropy: optional(SnapGetBip32EntropyPermissionsStruct),
   snap_getBip32PublicKey: optional(SnapGetBip32EntropyPermissionsStruct),
   snap_getBip44Entropy: optional(
@@ -230,8 +235,8 @@ export const PermissionsStruct = type({
       Infinity,
     ),
   ),
-  snap_getEntropy: optional(object({})),
-  snap_getLocale: optional(object({})),
+  snap_getEntropy: optional(EmptyObjectStruct),
+  snap_getLocale: optional(EmptyObjectStruct),
   wallet_snap: optional(SnapIdsStruct),
 });
 /* eslint-enable @typescript-eslint/naming-convention */