refactor: add superstruct and validate request/response utils (#305)

* chore: add superstruct

* chore: add rpc request validator utils

* chore: add test for rpc utils

packages/starknet-snap/package.json

@@ -44,7 +44,8 @@
     "ethereum-unit-converter": "^0.0.17",
     "ethers": "^5.5.1",
     "starknet": "6.11.0",
-    "starknet_v4.22.0": "npm:[email protected]"
+    "starknet_v4.22.0": "npm:[email protected]",
+    "superstruct": "^2.0.2"
   },
   "devDependencies": {
     "@babel/preset-typescript": "^7.23.3",

packages/starknet-snap/src/utils/rpc.test.ts

@@ -0,0 +1,51 @@
+import { InvalidParamsError, SnapError } from '@metamask/snaps-sdk';
+import { object } from 'superstruct';
+import type { Struct } from 'superstruct';
+
+import { validateRequest, validateResponse } from './rpc';
+import { AddressStruct } from './superstruct';
+
+const struct = object({
+  signerAddress: AddressStruct,
+});
+
+const params = {
+  signerAddress:
+    '0x04882a372da3dfe1c53170ad75893832469bf87b62b13e84662565c4a88f25cd',
+};
+
+describe('validateRequest', () => {
+  it('does not throw error if the request is valid', () => {
+    expect(() =>
+      validateRequest(params, struct as unknown as Struct),
+    ).not.toThrow();
+  });
+
+  it('throws `InvalidParamsError` if the request is invalid', () => {
+    const requestParams = {
+      signerAddress: 1234,
+    };
+
+    expect(() =>
+      validateRequest(requestParams, struct as unknown as Struct),
+    ).toThrow(InvalidParamsError);
+  });
+});
+
+describe('validateResponse', () => {
+  it('does not throw error if the response is valid', () => {
+    expect(() =>
+      validateResponse(params, struct as unknown as Struct),
+    ).not.toThrow();
+  });
+
+  it('throws `Invalid Response` error if the response is invalid', () => {
+    const response = {
+      signerAddress: 1234,
+    };
+
+    expect(() =>
+      validateResponse(response, struct as unknown as Struct),
+    ).toThrow(new SnapError('Invalid Response'));
+  });
+});

packages/starknet-snap/src/utils/rpc.ts

@@ -0,0 +1,35 @@
+import { InvalidParamsError, SnapError } from '@metamask/snaps-sdk';
+import type { Struct } from 'superstruct';
+import { assert } from 'superstruct';
+
+/**
+ * Validates that the request parameters conform to the expected structure defined by the provided struct.
+ *
+ * @template Params - The expected structure of the request parameters.
+ * @param requestParams - The request parameters to validate.
+ * @param struct - The expected structure of the request parameters.
+ * @throws {InvalidParamsError} If the request parameters do not conform to the expected structure.
+ */
+export function validateRequest<Params>(requestParams: Params, struct: Struct) {
+  try {
+    assert(requestParams, struct);
+  } catch (error) {
+    throw new InvalidParamsError(error.message) as unknown as Error;
+  }
+}
+
+/**
+ * Validates that the response conforms to the expected structure defined by the provided struct.
+ *
+ * @template Params - The expected structure of the response.
+ * @param response - The response to validate.
+ * @param struct - The expected structure of the response.
+ * @throws {SnapError} If the response does not conform to the expected structure.
+ */
+export function validateResponse<Params>(response: Params, struct: Struct) {
+  try {
+    assert(response, struct);
+  } catch (error) {
+    throw new SnapError('Invalid Response') as unknown as Error;
+  }
+}

packages/starknet-snap/src/utils/superstruct.test.ts

@@ -0,0 +1,21 @@
+import { StructError, assert } from 'superstruct';
+
+import { AddressStruct } from './superstruct';
+
+describe('AddressStruct', () => {
+  it.each([
+    '0x04882a372da3dfe1c53170ad75893832469bf87b62b13e84662565c4a88f25cd',
+    '4882a372da3dfe1c53170ad75893832469bf87b62b13e84662565c4a88f25cd',
+  ])('does not throw error if the address is valid - %s', (address) => {
+    expect(() => assert(address, AddressStruct)).not.toThrow();
+  });
+
+  it.each([
+    // non hex string - charactor is not within [0-9a-fA-F]
+    '0x04882a372da3dfe1c53170ad75893832469bf87b62b13e84662565c4a88f2zzz',
+    // invalid length - 66/63 chars expected
+    '372da3dfe1c53170ad75893832469bf87b62b13e84662565c4a88f25cd',
+  ])('throws error if the address is invalid - %s', (address) => {
+    expect(() => assert(address, AddressStruct)).toThrow(StructError);
+  });
+});

packages/starknet-snap/src/utils/superstruct.ts

@@ -0,0 +1,22 @@
+import { validateAndParseAddress } from 'starknet';
+import { refine, string } from 'superstruct';
+
+export const AddressStruct = refine(
+  string(),
+  'AddressStruct',
+  (value: string) => {
+    try {
+      const trimmedAddress = value.toString().replace(/^0x0?/u, '');
+
+      // Check if the address is 63 characters long, the expected length of a StarkNet address exclude 0x0.
+      if (trimmedAddress.length !== 63) {
+        return 'Invalid address format';
+      }
+
+      validateAndParseAddress(trimmedAddress);
+    } catch (error) {
+      return 'Invalid address format';
+    }
+    return true;
+  },
+);

yarn.lock

@@ -2274,6 +2274,7 @@ __metadata:
     sinon-chai: ^3.7.0
     starknet: 6.11.0
     starknet_v4.22.0: "npm:[email protected]"
+    superstruct: ^2.0.2
     ts-jest: ^29.1.0
     ts-node: ^10.9.2
     typescript: ^4.7.4
@@ -25626,6 +25627,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"superstruct@npm:^2.0.2":
+  version: 2.0.2
+  resolution: "superstruct@npm:2.0.2"
+  checksum: a5f75b72cb8b14b86f4f7f750dae8c5ab0e4e1d92414b55e7625bae07bbcafad81c92486e7e32ccacd6ae1f553caff2b92a50ff42ad5093fd35b9cb7f4e5ec86
+  languageName: node
+  linkType: hard
+
 "supports-color@npm:8.1.1, supports-color@npm:^8.0.0":
   version: 8.1.1
   resolution: "supports-color@npm:8.1.1"