From 98baa32c45af877cdead6133cc6a67579d61cd6c Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 09:19:08 +0200
Subject: [PATCH 01/15] feat: signer ready

---
 src/signer.ts | 49 +++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 43 insertions(+), 6 deletions(-)

diff --git a/src/signer.ts b/src/signer.ts
index e3843cb5..f31633ab 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -1,8 +1,12 @@
-import type {
-  IcrcWalletPermissionsRequestType,
-  IcrcWalletRequestPermissionsRequestType,
-  IcrcWalletSupportedStandardsRequestType
+import {nonNullish} from '@dfinity/utils';
+import {
+  IcrcWalletStatusRequest,
+  type IcrcWalletPermissionsRequestType,
+  type IcrcWalletRequestPermissionsRequestType,
+  type IcrcWalletSupportedStandardsRequestType
 } from './types/icrc-requests';
+import type {IcrcReadyResponseType} from './types/icrc-responses';
+import {JSON_RPC_VERSION_2} from './types/rpc';
 
 /**
  * The parameters to initialize a signer.
@@ -20,7 +24,7 @@ type SignerMessageEvent = MessageEvent<
 >;
 
 export class Signer {
-  readonly #walletOrigin: string | undefined;
+  #walletOrigin: string | undefined;
 
   private constructor(_parameters: SignerParameters) {
     window.addEventListener('message', this.onMessageListener);
@@ -50,5 +54,38 @@ export class Signer {
     void this.onMessage(message);
   };
 
-  private readonly onMessage = async (_message: SignerMessageEvent): Promise<void> => {};
+  private readonly onMessage = async ({
+    data: msgData,
+    origin
+  }: SignerMessageEvent): Promise<void> => {
+    this.assertAndSetOrigin(origin);
+
+    const {success: isStatusRequest, data} = IcrcWalletStatusRequest.safeParse(msgData);
+
+    if (isStatusRequest) {
+      const notifyReady = (): void => {
+        const msg: IcrcReadyResponseType = {
+          jsonrpc: JSON_RPC_VERSION_2,
+          id: data.id,
+          result: 'ready'
+        };
+
+        window.opener.postMessage(msg, origin);
+      };
+
+      notifyReady();
+    }
+  };
+
+  private assertAndSetOrigin(origin: string): void {
+    if (nonNullish(this.#walletOrigin) && this.#walletOrigin !== origin) {
+      throw new Error('Origin is not allowed to interact with the signer');
+    }
+
+    if (nonNullish(this.#walletOrigin)) {
+      return;
+    }
+
+    this.#walletOrigin = origin;
+  }
 }

From b0e0feb9f6f14ccdc71d177edac9da836943b0d0 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 09:41:48 +0200
Subject: [PATCH 02/15] feat: extract signer handler

---
 src/handlers/signer.handlers.ts | 12 ++++++++++++
 src/signer.ts                   | 16 +++-------------
 2 files changed, 15 insertions(+), 13 deletions(-)
 create mode 100644 src/handlers/signer.handlers.ts

diff --git a/src/handlers/signer.handlers.ts b/src/handlers/signer.handlers.ts
new file mode 100644
index 00000000..a64ba9ef
--- /dev/null
+++ b/src/handlers/signer.handlers.ts
@@ -0,0 +1,12 @@
+import type {IcrcReadyResponseType} from '../types/icrc-responses';
+import {JSON_RPC_VERSION_2} from '../types/rpc';
+
+export const notifyReady = ({msgId: id}: {msgId: string}): void => {
+  const msg: IcrcReadyResponseType = {
+    jsonrpc: JSON_RPC_VERSION_2,
+    id,
+    result: 'ready'
+  };
+
+  window.opener.postMessage(msg, origin);
+};
diff --git a/src/signer.ts b/src/signer.ts
index f31633ab..bf995962 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -1,12 +1,11 @@
 import {nonNullish} from '@dfinity/utils';
+import {notifyReady} from './handlers/signer.handlers';
 import {
   IcrcWalletStatusRequest,
   type IcrcWalletPermissionsRequestType,
   type IcrcWalletRequestPermissionsRequestType,
   type IcrcWalletSupportedStandardsRequestType
 } from './types/icrc-requests';
-import type {IcrcReadyResponseType} from './types/icrc-responses';
-import {JSON_RPC_VERSION_2} from './types/rpc';
 
 /**
  * The parameters to initialize a signer.
@@ -63,17 +62,8 @@ export class Signer {
     const {success: isStatusRequest, data} = IcrcWalletStatusRequest.safeParse(msgData);
 
     if (isStatusRequest) {
-      const notifyReady = (): void => {
-        const msg: IcrcReadyResponseType = {
-          jsonrpc: JSON_RPC_VERSION_2,
-          id: data.id,
-          result: 'ready'
-        };
-
-        window.opener.postMessage(msg, origin);
-      };
-
-      notifyReady();
+      const {id: msgId} = data;
+      notifyReady({msgId});
     }
   };
 

From f8479aa7ee181fa0497c01b7b158a6ec55e78d85 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 11:48:56 +0200
Subject: [PATCH 03/15] feat: request type

---
 src/handlers/signer.handlers.ts | 4 ++--
 src/signer.ts                   | 4 ++--
 src/types/rpc.ts                | 2 ++
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/handlers/signer.handlers.ts b/src/handlers/signer.handlers.ts
index a64ba9ef..2f04c564 100644
--- a/src/handlers/signer.handlers.ts
+++ b/src/handlers/signer.handlers.ts
@@ -1,7 +1,7 @@
 import type {IcrcReadyResponseType} from '../types/icrc-responses';
-import {JSON_RPC_VERSION_2} from '../types/rpc';
+import {JSON_RPC_VERSION_2, type RpcIdType} from '../types/rpc';
 
-export const notifyReady = ({msgId: id}: {msgId: string}): void => {
+export const notifyReady = ({id}: {id: RpcIdType}): void => {
   const msg: IcrcReadyResponseType = {
     jsonrpc: JSON_RPC_VERSION_2,
     id,
diff --git a/src/signer.ts b/src/signer.ts
index bf995962..4cb75274 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -62,8 +62,8 @@ export class Signer {
     const {success: isStatusRequest, data} = IcrcWalletStatusRequest.safeParse(msgData);
 
     if (isStatusRequest) {
-      const {id: msgId} = data;
-      notifyReady({msgId});
+      const {id} = data;
+      notifyReady({id});
     }
   };
 
diff --git a/src/types/rpc.ts b/src/types/rpc.ts
index 0c42f896..74a7e88e 100644
--- a/src/types/rpc.ts
+++ b/src/types/rpc.ts
@@ -9,6 +9,8 @@ const JsonRpc = z.literal(JSON_RPC_VERSION_2);
 
 const RpcId = z.union([z.string(), z.number(), z.null()]);
 
+export type RpcIdType = z.infer<typeof RpcId>;
+
 const Rpc = z.object({
   jsonrpc: JsonRpc,
   id: z.optional(RpcId)

From 0e9abec8a3c0739cdc028e760ca7c4fcdc800737 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 14:02:32 +0200
Subject: [PATCH 04/15] feat: post message to origin

---
 src/handlers/signer.handlers.ts | 2 +-
 src/signer.ts                   | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/handlers/signer.handlers.ts b/src/handlers/signer.handlers.ts
index 2f04c564..315bb7bc 100644
--- a/src/handlers/signer.handlers.ts
+++ b/src/handlers/signer.handlers.ts
@@ -1,7 +1,7 @@
 import type {IcrcReadyResponseType} from '../types/icrc-responses';
 import {JSON_RPC_VERSION_2, type RpcIdType} from '../types/rpc';
 
-export const notifyReady = ({id}: {id: RpcIdType}): void => {
+export const notifyReady = ({id, origin}: {id: RpcIdType; origin: string}): void => {
   const msg: IcrcReadyResponseType = {
     jsonrpc: JSON_RPC_VERSION_2,
     id,
diff --git a/src/signer.ts b/src/signer.ts
index 4cb75274..f49fa944 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -63,15 +63,16 @@ export class Signer {
 
     if (isStatusRequest) {
       const {id} = data;
-      notifyReady({id});
+      notifyReady({id, origin});
     }
   };
 
   private assertAndSetOrigin(origin: string): void {
     if (nonNullish(this.#walletOrigin) && this.#walletOrigin !== origin) {
-      throw new Error('Origin is not allowed to interact with the signer');
+      throw new Error(`The relying party's origin is not allowed to interact with the signer.`);
     }
 
+    // We do not reassign the origin with the same value if it is already set. It is not a significant performance win.
     if (nonNullish(this.#walletOrigin)) {
       return;
     }

From 31172f534045aa56495041053256fb78914bfc96 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 14:14:49 +0200
Subject: [PATCH 05/15] test: signer handler

---
 src/handlers/signer.handlers.spec.ts | 41 ++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 src/handlers/signer.handlers.spec.ts

diff --git a/src/handlers/signer.handlers.spec.ts b/src/handlers/signer.handlers.spec.ts
new file mode 100644
index 00000000..a0a07802
--- /dev/null
+++ b/src/handlers/signer.handlers.spec.ts
@@ -0,0 +1,41 @@
+import type {Mock} from 'vitest';
+import type {IcrcReadyResponseType} from '../types/icrc-responses';
+import {JSON_RPC_VERSION_2, RpcIdType} from '../types/rpc';
+import {notifyReady} from './signer.handlers';
+
+describe('Signer handlers', () => {
+  let originalOpener: typeof window.opener;
+
+  let postMessageMock: Mock;
+
+  beforeEach(() => {
+    originalOpener = window.opener;
+
+    postMessageMock = vi.fn();
+
+    vi.stubGlobal('opener', {postMessage: postMessageMock});
+  });
+
+  afterEach(() => {
+    window.opener = originalOpener;
+
+    vi.restoreAllMocks();
+  });
+
+  describe('notifyReady', () => {
+    it('should post a message with the msg', () => {
+      const id: RpcIdType = 'test-123';
+      const origin = 'https://hello.com';
+
+      notifyReady({id, origin});
+
+      const expectedMessage: IcrcReadyResponseType = {
+        jsonrpc: JSON_RPC_VERSION_2,
+        id,
+        result: 'ready'
+      };
+
+      expect(postMessageMock).toHaveBeenCalledWith(expectedMessage, origin);
+    });
+  });
+});

From 24bdb02371d7f03f92d126b775937a5521c5f707 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 14:20:49 +0200
Subject: [PATCH 06/15] chore: lint

---
 src/handlers/signer.handlers.spec.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/handlers/signer.handlers.spec.ts b/src/handlers/signer.handlers.spec.ts
index a0a07802..3874ddf3 100644
--- a/src/handlers/signer.handlers.spec.ts
+++ b/src/handlers/signer.handlers.spec.ts
@@ -1,6 +1,6 @@
 import type {Mock} from 'vitest';
 import type {IcrcReadyResponseType} from '../types/icrc-responses';
-import {JSON_RPC_VERSION_2, RpcIdType} from '../types/rpc';
+import {JSON_RPC_VERSION_2, type RpcIdType} from '../types/rpc';
 import {notifyReady} from './signer.handlers';
 
 describe('Signer handlers', () => {

From e8528a2c0c79ce7a8622b57a0020caa24f124626 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 14:43:50 +0200
Subject: [PATCH 07/15] feat: reset origin

---
 src/signer.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/signer.ts b/src/signer.ts
index f49fa944..e1400fd1 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -23,7 +23,7 @@ type SignerMessageEvent = MessageEvent<
 >;
 
 export class Signer {
-  #walletOrigin: string | undefined;
+  #walletOrigin: string | undefined | null;
 
   private constructor(_parameters: SignerParameters) {
     window.addEventListener('message', this.onMessageListener);
@@ -47,6 +47,7 @@ export class Signer {
    */
   disconnect = (): void => {
     window.removeEventListener('message', this.onMessageListener);
+    this.#walletOrigin = null;
   };
 
   private readonly onMessageListener = (message: SignerMessageEvent): void => {

From 02f854db75eaadd77839d5c46312521829039bbf Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 14:43:57 +0200
Subject: [PATCH 08/15] test: init origin test

---
 src/signer.spec.ts | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/src/signer.spec.ts b/src/signer.spec.ts
index 81ca2ab4..9d6a0fda 100644
--- a/src/signer.spec.ts
+++ b/src/signer.spec.ts
@@ -1,5 +1,8 @@
 import {type MockInstance} from 'vitest';
+import * as signerHandlers from './handlers/signer.handlers';
 import {Signer, type SignerParameters} from './signer';
+import {ICRC29_STATUS} from './types/icrc';
+import {JSON_RPC_VERSION_2} from './types/rpc';
 
 describe('Signer', () => {
   const mockParameters: SignerParameters = {};
@@ -61,4 +64,41 @@ describe('Signer', () => {
       expect(onMessageListenerSpy).not.toHaveBeenCalled();
     });
   });
+
+  describe('assertAndSetOrigin', () => {
+    let notifyReadySpy: MockInstance;
+    let signer: Signer;
+
+    beforeEach(() => {
+      signer = Signer.init(mockParameters);
+      notifyReadySpy = vi.spyOn(signerHandlers, 'notifyReady');
+    });
+
+    afterEach(() => {
+      signer.disconnect();
+      vi.clearAllMocks();
+    });
+
+    it('should set the origin if it is not set', () => {
+      const testOrigin = 'https://hello.com';
+
+      let testId = 'test-123';
+
+      const messageEvent = new MessageEvent('message', {
+        data: {
+          id: testId,
+          jsonrpc: JSON_RPC_VERSION_2,
+          method: ICRC29_STATUS
+        },
+        origin: testOrigin
+      });
+
+      window.dispatchEvent(messageEvent);
+
+      expect(notifyReadySpy).toHaveBeenCalledWith({
+        id: testId,
+        origin: testOrigin
+      });
+    });
+  });
 });

From d6336b0c896652336f3ce921ad7f0110dea6c90b Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 15:25:02 +0200
Subject: [PATCH 09/15] test: origin and post msg

---
 src/signer.spec.ts | 63 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 61 insertions(+), 2 deletions(-)

diff --git a/src/signer.spec.ts b/src/signer.spec.ts
index 9d6a0fda..8611bfe1 100644
--- a/src/signer.spec.ts
+++ b/src/signer.spec.ts
@@ -65,21 +65,28 @@ describe('Signer', () => {
     });
   });
 
-  describe('assertAndSetOrigin', () => {
+  describe('origin and postMessage', () => {
+    let originalOpener: typeof window.opener;
+
     let notifyReadySpy: MockInstance;
     let signer: Signer;
 
     beforeEach(() => {
       signer = Signer.init(mockParameters);
       notifyReadySpy = vi.spyOn(signerHandlers, 'notifyReady');
+      vi.stubGlobal('opener', {postMessage: vi.fn()});
     });
 
     afterEach(() => {
       signer.disconnect();
+
+      window.opener = originalOpener;
+
       vi.clearAllMocks();
+      vi.restoreAllMocks();
     });
 
-    it('should set the origin if it is not set', () => {
+    it('should use the origin and respond with a post message', () => {
       const testOrigin = 'https://hello.com';
 
       let testId = 'test-123';
@@ -100,5 +107,57 @@ describe('Signer', () => {
         origin: testOrigin
       });
     });
+
+    it('should throw an error if a message from different origin is dispatched', () => {
+      const testOrigin = 'https://hello.com';
+      const differentOrigin = 'https://test.com';
+
+      let testId = 'test-123';
+
+      const msg = {
+        data: {
+          id: testId,
+          jsonrpc: JSON_RPC_VERSION_2,
+          method: ICRC29_STATUS
+        },
+        origin: testOrigin
+      };
+
+      const messageEvent = new MessageEvent('message', msg);
+      window.dispatchEvent(messageEvent);
+
+      const messageEventDiff = new MessageEvent('message', {...msg, origin: differentOrigin});
+
+      // TODO: error
+
+      window.dispatchEvent(messageEventDiff);
+    });
+
+    it('should reset #walletOrigin to null after disconnect', () => {
+      const testOrigin = 'https://hello.com';
+      const differentOrigin = 'https://world.com';
+
+      let testId = 'test-123';
+
+      const msg = {
+        data: {
+          id: testId,
+          jsonrpc: JSON_RPC_VERSION_2,
+          method: ICRC29_STATUS
+        },
+        origin: testOrigin
+      };
+
+      const messageEvent = new MessageEvent('message', msg);
+      window.dispatchEvent(messageEvent);
+
+      const messageEventDiff = new MessageEvent('message', {...msg, origin: differentOrigin});
+
+      signer.disconnect();
+
+      expect(() => {
+        window.dispatchEvent(messageEventDiff);
+      }).not.toThrow();
+    });
   });
 });

From 5d1aff65ae4bc74d1fa3970f936d532b012edd5a Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Tue, 30 Jul 2024 16:37:17 +0200
Subject: [PATCH 10/15] test: skip for now

---
 src/signer.spec.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/signer.spec.ts b/src/signer.spec.ts
index 8611bfe1..bf884f03 100644
--- a/src/signer.spec.ts
+++ b/src/signer.spec.ts
@@ -108,7 +108,7 @@ describe('Signer', () => {
       });
     });
 
-    it('should throw an error if a message from different origin is dispatched', () => {
+    it.skip('should throw an error if a message from different origin is dispatched', () => {
       const testOrigin = 'https://hello.com';
       const differentOrigin = 'https://test.com';
 

From d89801783c358b018d5dba8ea64874f9936ed9ed Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Wed, 31 Jul 2024 08:56:25 +0200
Subject: [PATCH 11/15] feat: rpc errors

---
 src/constants/signer.constants.ts |  6 +++++
 src/handlers/signer.handlers.ts   | 38 +++++++++++++++++++++++++++---
 src/signer.spec.ts                |  8 ++-----
 src/signer.ts                     | 39 +++++++++++++++++++++++--------
 src/types/rpc.ts                  | 29 +++++++++++++++--------
 5 files changed, 91 insertions(+), 29 deletions(-)
 create mode 100644 src/constants/signer.constants.ts

diff --git a/src/constants/signer.constants.ts b/src/constants/signer.constants.ts
new file mode 100644
index 00000000..196044b7
--- /dev/null
+++ b/src/constants/signer.constants.ts
@@ -0,0 +1,6 @@
+export enum SignerErrorCode {
+  /**
+   * The relying party's origin is not allowed to interact with the signer.
+   */
+  ORIGIN_ERROR = 500
+}
diff --git a/src/handlers/signer.handlers.ts b/src/handlers/signer.handlers.ts
index 315bb7bc..7c085a4d 100644
--- a/src/handlers/signer.handlers.ts
+++ b/src/handlers/signer.handlers.ts
@@ -1,12 +1,44 @@
 import type {IcrcReadyResponseType} from '../types/icrc-responses';
-import {JSON_RPC_VERSION_2, type RpcIdType} from '../types/rpc';
+import {
+  JSON_RPC_VERSION_2,
+  type RpcIdType,
+  type RpcResponseErrorType,
+  type RpcResponseType,
+  type RpcResponseWithErrorType
+} from '../types/rpc';
 
-export const notifyReady = ({id, origin}: {id: RpcIdType; origin: string}): void => {
+interface Notify {
+  id: RpcIdType;
+  origin: string;
+}
+
+export const notifyReady = ({id, origin}: Notify): void => {
   const msg: IcrcReadyResponseType = {
     jsonrpc: JSON_RPC_VERSION_2,
     id,
     result: 'ready'
   };
 
-  window.opener.postMessage(msg, origin);
+  notify({msg, origin});
 };
+
+export const notifyAndThrowError = ({
+  id,
+  error,
+  origin
+}: {
+  error: RpcResponseErrorType;
+} & Notify): never => {
+  const msg: RpcResponseWithErrorType = {
+    jsonrpc: JSON_RPC_VERSION_2,
+    id,
+    error
+  };
+
+  notify({msg, origin});
+
+  throw new Error(error.message);
+};
+
+const notify = ({msg, origin}: {msg: RpcResponseType} & Pick<Notify, 'origin'>): void =>
+  window.opener.postMessage(msg, origin);
diff --git a/src/signer.spec.ts b/src/signer.spec.ts
index bf884f03..b2e7077a 100644
--- a/src/signer.spec.ts
+++ b/src/signer.spec.ts
@@ -66,6 +66,8 @@ describe('Signer', () => {
   });
 
   describe('origin and postMessage', () => {
+    const testId = 'test-123';
+
     let originalOpener: typeof window.opener;
 
     let notifyReadySpy: MockInstance;
@@ -89,8 +91,6 @@ describe('Signer', () => {
     it('should use the origin and respond with a post message', () => {
       const testOrigin = 'https://hello.com';
 
-      let testId = 'test-123';
-
       const messageEvent = new MessageEvent('message', {
         data: {
           id: testId,
@@ -112,8 +112,6 @@ describe('Signer', () => {
       const testOrigin = 'https://hello.com';
       const differentOrigin = 'https://test.com';
 
-      let testId = 'test-123';
-
       const msg = {
         data: {
           id: testId,
@@ -137,8 +135,6 @@ describe('Signer', () => {
       const testOrigin = 'https://hello.com';
       const differentOrigin = 'https://world.com';
 
-      let testId = 'test-123';
-
       const msg = {
         data: {
           id: testId,
diff --git a/src/signer.ts b/src/signer.ts
index e1400fd1..cf330483 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -1,11 +1,13 @@
 import {nonNullish} from '@dfinity/utils';
-import {notifyReady} from './handlers/signer.handlers';
+import {SignerErrorCode} from './constants/signer.constants';
+import {notifyAndThrowError, notifyReady} from './handlers/signer.handlers';
 import {
   IcrcWalletStatusRequest,
   type IcrcWalletPermissionsRequestType,
   type IcrcWalletRequestPermissionsRequestType,
   type IcrcWalletSupportedStandardsRequestType
 } from './types/icrc-requests';
+import {RpcRequest} from './types/rpc';
 
 /**
  * The parameters to initialize a signer.
@@ -14,14 +16,14 @@ import {
 // eslint-disable-next-line @typescript-eslint/no-empty-interface
 export interface SignerParameters {}
 
-type SignerMessageEvent = MessageEvent<
-  Partial<
-    | IcrcWalletRequestPermissionsRequestType
-    | IcrcWalletPermissionsRequestType
-    | IcrcWalletSupportedStandardsRequestType
-  >
+type SignerMessageEventData = Partial<
+  | IcrcWalletRequestPermissionsRequestType
+  | IcrcWalletPermissionsRequestType
+  | IcrcWalletSupportedStandardsRequestType
 >;
 
+type SignerMessageEvent = MessageEvent<SignerMessageEventData>;
+
 export class Signer {
   #walletOrigin: string | undefined | null;
 
@@ -58,7 +60,7 @@ export class Signer {
     data: msgData,
     origin
   }: SignerMessageEvent): Promise<void> => {
-    this.assertAndSetOrigin(origin);
+    this.assertAndSetOrigin({msgData, origin});
 
     const {success: isStatusRequest, data} = IcrcWalletStatusRequest.safeParse(msgData);
 
@@ -68,9 +70,26 @@ export class Signer {
     }
   };
 
-  private assertAndSetOrigin(origin: string): void {
+  private assertAndSetOrigin({
+    msgData,
+    origin
+  }: {
+    origin: string;
+    msgData: SignerMessageEventData;
+  }): void {
     if (nonNullish(this.#walletOrigin) && this.#walletOrigin !== origin) {
-      throw new Error(`The relying party's origin is not allowed to interact with the signer.`);
+      const {data} = RpcRequest.safeParse(msgData);
+
+      notifyAndThrowError({
+        id: data?.id ?? null,
+        origin,
+        error: {
+          code: SignerErrorCode.ORIGIN_ERROR,
+          message: `The relying party's origin is not allowed to interact with the signer.`
+        }
+      });
+      // Typescript safety
+      return;
     }
 
     // We do not reassign the origin with the same value if it is already set. It is not a significant performance win.
diff --git a/src/types/rpc.ts b/src/types/rpc.ts
index 74a7e88e..0a0e106b 100644
--- a/src/types/rpc.ts
+++ b/src/types/rpc.ts
@@ -16,7 +16,7 @@ const Rpc = z.object({
   id: z.optional(RpcId)
 });
 
-const RpcRequest = Rpc.extend({
+export const RpcRequest = Rpc.extend({
   id: RpcId
 })
   .merge(
@@ -95,11 +95,13 @@ const RpcResponseError = z.object({
   data: z.optional(z.never())
 });
 
+export type RpcResponseErrorType = z.infer<typeof RpcResponseError>;
+
 const RpcResponse = Rpc.extend({
   id: RpcId
 });
 
-type RpcResponseType = z.infer<typeof RpcResponse>;
+export type RpcResponseType = z.infer<typeof RpcResponse>;
 
 const RpcResponseContent = z
   .object({
@@ -110,17 +112,24 @@ const RpcResponseContent = z
 
 type RpcResponseContentType = z.infer<typeof RpcResponseContent>;
 
+const RpcResponseWithError = RpcResponse.extend({
+  error: RpcResponseError
+});
+
+export type RpcResponseWithErrorType = z.infer<typeof RpcResponseWithError>;
+
 export const inferRpcResponse = <T extends z.ZodTypeAny>(
   result: T
 ): z.ZodType<RpcResponseType & RpcResponseContentType> =>
-  RpcResponse.merge(
-    z
-      .object({
-        result,
-        error: RpcResponseError
-      })
-      .partial()
-  )
+  RpcResponseWithError.omit({error: true})
+    .merge(
+      z
+        .object({
+          result,
+          error: RpcResponseError
+        })
+        .partial()
+    )
     .strict()
     .refine(
       ({result, error}) => result !== undefined || error !== undefined,

From 2d5935f3fc2cd6f5905cf3add12e353c5453a399 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Wed, 31 Jul 2024 09:14:53 +0200
Subject: [PATCH 12/15] feat: test and do not throw on notify error

---
 src/handlers/signer.handlers.ts |  6 ++----
 src/signer.spec.ts              | 22 +++++++++++++++++-----
 src/signer.ts                   |  6 +++---
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/src/handlers/signer.handlers.ts b/src/handlers/signer.handlers.ts
index 7c085a4d..375f4112 100644
--- a/src/handlers/signer.handlers.ts
+++ b/src/handlers/signer.handlers.ts
@@ -22,13 +22,13 @@ export const notifyReady = ({id, origin}: Notify): void => {
   notify({msg, origin});
 };
 
-export const notifyAndThrowError = ({
+export const notifyError = ({
   id,
   error,
   origin
 }: {
   error: RpcResponseErrorType;
-} & Notify): never => {
+} & Notify): void => {
   const msg: RpcResponseWithErrorType = {
     jsonrpc: JSON_RPC_VERSION_2,
     id,
@@ -36,8 +36,6 @@ export const notifyAndThrowError = ({
   };
 
   notify({msg, origin});
-
-  throw new Error(error.message);
 };
 
 const notify = ({msg, origin}: {msg: RpcResponseType} & Pick<Notify, 'origin'>): void =>
diff --git a/src/signer.spec.ts b/src/signer.spec.ts
index b2e7077a..8c9267f2 100644
--- a/src/signer.spec.ts
+++ b/src/signer.spec.ts
@@ -73,10 +73,13 @@ describe('Signer', () => {
     let notifyReadySpy: MockInstance;
     let signer: Signer;
 
+    let postMessageMock: MockInstance;
+
     beforeEach(() => {
       signer = Signer.init(mockParameters);
       notifyReadySpy = vi.spyOn(signerHandlers, 'notifyReady');
-      vi.stubGlobal('opener', {postMessage: vi.fn()});
+      postMessageMock = vi.fn();
+      vi.stubGlobal('opener', {postMessage: postMessageMock});
     });
 
     afterEach(() => {
@@ -108,7 +111,7 @@ describe('Signer', () => {
       });
     });
 
-    it.skip('should throw an error if a message from different origin is dispatched', () => {
+    it('should notify an error if a message from different origin is dispatched', () => {
       const testOrigin = 'https://hello.com';
       const differentOrigin = 'https://test.com';
 
@@ -125,10 +128,19 @@ describe('Signer', () => {
       window.dispatchEvent(messageEvent);
 
       const messageEventDiff = new MessageEvent('message', {...msg, origin: differentOrigin});
-
-      // TODO: error
-
       window.dispatchEvent(messageEventDiff);
+
+      expect(postMessageMock).toHaveBeenCalledWith(
+        {
+          jsonrpc: JSON_RPC_VERSION_2,
+          id: testId,
+          error: {
+            code: 500,
+            message: "The relying party's origin is not allowed to interact with the signer."
+          }
+        },
+        differentOrigin
+      );
     });
 
     it('should reset #walletOrigin to null after disconnect', () => {
diff --git a/src/signer.ts b/src/signer.ts
index cf330483..5a2bdebe 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -1,6 +1,6 @@
 import {nonNullish} from '@dfinity/utils';
 import {SignerErrorCode} from './constants/signer.constants';
-import {notifyAndThrowError, notifyReady} from './handlers/signer.handlers';
+import {notifyError, notifyReady} from './handlers/signer.handlers';
 import {
   IcrcWalletStatusRequest,
   type IcrcWalletPermissionsRequestType,
@@ -80,7 +80,7 @@ export class Signer {
     if (nonNullish(this.#walletOrigin) && this.#walletOrigin !== origin) {
       const {data} = RpcRequest.safeParse(msgData);
 
-      notifyAndThrowError({
+      notifyError({
         id: data?.id ?? null,
         origin,
         error: {
@@ -88,7 +88,7 @@ export class Signer {
           message: `The relying party's origin is not allowed to interact with the signer.`
         }
       });
-      // Typescript safety
+
       return;
     }
 

From bdfd69487e114fa66ef4e846f50c5f8f539a0dc6 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Wed, 31 Jul 2024 12:30:18 +0200
Subject: [PATCH 13/15] docs: todo

---
 src/signer.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/signer.ts b/src/signer.ts
index 5a2bdebe..d646fd5b 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -60,6 +60,9 @@ export class Signer {
     data: msgData,
     origin
   }: SignerMessageEvent): Promise<void> => {
+    // TODO: ignore messages that are not Rpc Requests.
+    // TODO: assert messages to notify error if methods are not supported.
+
     this.assertAndSetOrigin({msgData, origin});
 
     const {success: isStatusRequest, data} = IcrcWalletStatusRequest.safeParse(msgData);

From 4269c4e338683c85004832d9cbfd02d71409a425 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Wed, 31 Jul 2024 12:41:46 +0200
Subject: [PATCH 14/15] test: READY

---
 src/signer.spec.ts | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/src/signer.spec.ts b/src/signer.spec.ts
index 8c9267f2..619df53e 100644
--- a/src/signer.spec.ts
+++ b/src/signer.spec.ts
@@ -168,4 +168,56 @@ describe('Signer', () => {
       }).not.toThrow();
     });
   });
+
+  describe('READY postMessage', () => {
+    const testId = 'test-123';
+
+    let originalOpener: typeof window.opener;
+
+    let signer: Signer;
+
+    let postMessageMock: MockInstance;
+
+    beforeEach(() => {
+      signer = Signer.init(mockParameters);
+
+      postMessageMock = vi.fn();
+
+      vi.stubGlobal('opener', {postMessage: postMessageMock});
+    });
+
+    afterEach(() => {
+      signer.disconnect();
+
+      window.opener = originalOpener;
+
+      vi.clearAllMocks();
+      vi.restoreAllMocks();
+    });
+
+    it('should notify READY', () => {
+      const testOrigin = 'https://hello.com';
+
+      const msg = {
+        data: {
+          id: testId,
+          jsonrpc: JSON_RPC_VERSION_2,
+          method: ICRC29_STATUS
+        },
+        origin: testOrigin
+      };
+
+      const messageEvent = new MessageEvent('message', msg);
+      window.dispatchEvent(messageEvent);
+
+      expect(postMessageMock).toHaveBeenCalledWith(
+        {
+          jsonrpc: JSON_RPC_VERSION_2,
+          id: testId,
+          result: 'ready'
+        },
+        testOrigin
+      );
+    });
+  });
 });

From fa2cd7c9b08c514c5bf45e7676f6169aad88ad69 Mon Sep 17 00:00:00 2001
From: David Dal Busco <david.dalbusco@outlook.com>
Date: Wed, 31 Jul 2024 18:12:49 +0200
Subject: [PATCH 15/15] chore: merge main

---
 src/signer.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/signer.ts b/src/signer.ts
index c50eb462..d646fd5b 100644
--- a/src/signer.ts
+++ b/src/signer.ts
@@ -63,7 +63,6 @@ export class Signer {
     // TODO: ignore messages that are not Rpc Requests.
     // TODO: assert messages to notify error if methods are not supported.
 
-
     this.assertAndSetOrigin({msgData, origin});
 
     const {success: isStatusRequest, data} = IcrcWalletStatusRequest.safeParse(msgData);