Improve keyring endowment error messaging

packages/controllers/src/snaps/endowments/keyring.test.ts

@@ -181,7 +181,9 @@ describe('keyringCaveatSpecifications', () => {
             namespaces: undefined,
           },
         }),
-      ).toThrow('Expected a valid namespaces object.');
+      ).toThrow(
+        'Invalid namespaces object: Expected an object, but received: undefined.',
+      );
     });
   });
 });

packages/controllers/src/snaps/endowments/keyring.ts

@@ -1,7 +1,7 @@
 import {
-  isNamespacesObject,
   Namespaces,
   SnapCaveatType,
+  validateNamespacesObject,
 } from '@metamask/snap-utils';
 import {
   Caveat,
@@ -92,9 +92,10 @@ function validateCaveatNamespace(caveat: Caveat<string, any>): void {
     });
   }
 
-  if (!isNamespacesObject(value.namespaces)) {
+  const [error] = validateNamespacesObject(value.namespaces);
+  if (error) {
     throw ethErrors.rpc.invalidParams({
-      message: 'Expected a valid namespaces object.',
+      message: `Invalid namespaces object: ${error.message}.`,
     });
   }
 }

packages/utils/jest.config.js

@@ -16,9 +16,9 @@ module.exports = {
   coverageThreshold: {
     global: {
       branches: 86.05,
-      functions: 97.14,
-      lines: 96.79,
-      statements: 96.86,
+      functions: 97.16,
+      lines: 96.8,
+      statements: 96.87,
     },
   },
   moduleFileExtensions: ['js', 'json', 'jsx', 'ts', 'tsx', 'node'],

packages/utils/src/namespace.test.ts

@@ -1,3 +1,4 @@
+import { StructError } from 'superstruct';
 import {
   getChain,
   getNamespace,
@@ -18,6 +19,7 @@ import {
   isNamespacesObject,
   parseAccountId,
   parseChainId,
+  validateNamespacesObject,
 } from './namespace';
 
 describe('parseChainId', () => {
@@ -645,3 +647,41 @@ describe('isNamespacesObject', () => {
     expect(isNamespacesObject(object)).toBe(false);
   });
 });
+
+describe('validateNamespacesObject', () => {
+  it.each([
+    {},
+    { eip155: getNamespace() },
+    { bip122: getNamespace() },
+    { eip155: getNamespace(), bip122: getNamespace() },
+  ])('returns the object for a valid namespaces object', (object) => {
+    expect(validateNamespacesObject(object)).toStrictEqual([undefined, object]);
+  });
+
+  it.each([
+    true,
+    false,
+    null,
+    undefined,
+    1,
+    'foo',
+    { eip155: {} },
+    { eip155: [], bip122: [] },
+    { eip155: true, bip122: true },
+    { eip155: false, bip122: false },
+    { eip155: null, bip122: null },
+    { eip155: undefined, bip122: undefined },
+    { eip155: 1, bip122: 1 },
+    { eip155: 'foo', bip122: 'foo' },
+    { eip155: { methods: [] }, bip122: { methods: [] } },
+    { eip155: { chains: ['foo'] }, bip122: { chains: ['foo'] } },
+    { a: getNamespace() },
+    { eip155: getNamespace(), a: getNamespace() },
+    { foobarbaz: getNamespace() },
+  ])('returns an error for an invalid namespaces object', (object) => {
+    expect(validateNamespacesObject(object)).toStrictEqual([
+      expect.any(StructError),
+      undefined,
+    ]);
+  });
+});

packages/utils/src/namespace.ts

@@ -12,8 +12,10 @@ import {
   assign,
   partial,
   pick,
+  validate,
 } from 'superstruct';
 import { JsonRpcRequestStruct } from '@metamask/utils';
+import { StructError } from 'superstruct/lib/error';
 import { assertStruct } from './assert';
 
 export const CHAIN_ID_REGEX =
@@ -276,3 +278,19 @@ export function isNamespace(value: unknown): value is Namespace {
 export function isNamespacesObject(value: unknown): value is Namespaces {
   return is(value, NamespacesStruct);
 }
+
+/**
+ * Check if a value is an object containing {@link Namespaces}s. This behaves
+ * the same as {@link isNamespacesObject}, but rather than returning a boolean,
+ * it returns a tuple containing an error message if the value is not valid, or
+ * the validated value if it is.
+ *
+ * @param value - The value to validate.
+ * @returns A tuple containing an error message if the value is not valid, or
+ * the validated value if it is.
+ */
+export function validateNamespacesObject(
+  value: unknown,
+): [StructError, undefined] | [undefined, Namespaces] {
+  return validate(value, NamespacesStruct);
+}