Better error handling

Author: cloutiertyler

packages/sdk/src/algebraic_type.ts

@@ -363,7 +363,10 @@ export class AlgebraicType {
   }
   static createTimestampType(): AlgebraicType {
     return this.createProductType([
-      new ProductTypeElement('__timestamp_micros_since_unix_epoch__', this.createI64Type()),
+      new ProductTypeElement(
+        '__timestamp_micros_since_unix_epoch__',
+        this.createI64Type()
+      ),
     ]);
   }
   static createAddressType(): AlgebraicType {
@@ -408,7 +411,7 @@ export class AlgebraicType {
       this.product.elements[0].name === tag
     );
   }
-  
+
   isTimestamp(): boolean {
     return this.#isBytesNewtype('__timestamp_micros_since_unix_epoch__');
   }

packages/sdk/src/subscription_builder_impl.ts

@@ -129,22 +129,13 @@ export class SubscriptionManager {
   > = new Map();
 }
 
-type Result<T = undefined> =
-  | {
-      tag: 'Ok';
-      value: T;
-    }
-  | {
-      tag: 'Err';
-      value: Error;
-    };
-
 export class SubscriptionHandleImpl<
   DBView = any,
   Reducers = any,
   SetReducerFlags = any,
 > {
   #queryId: number;
+  #unsubscribeCalled: boolean = false;
   #endedState: boolean = false;
   #activeState: boolean = false;
   #emitter: EventEmitter<SubscribeEvent, (...args: any[]) => void> =
@@ -195,10 +186,13 @@ export class SubscriptionHandleImpl<
    * removing this query from the client's set of subscribed queries.
    * It is only valid to call this method if `is_active()` is `true`.
    */
-  unsubscribe(): Result {
+  unsubscribe(): void {
+    if (this.#unsubscribeCalled) {
+      throw new Error('Unsubscribe has already been called');
+    }
+    this.#unsubscribeCalled = true;
     this.db.unregisterSubscription(this.#queryId);
     this.db['unsubscribe'](this.#queryId);
-    return { tag: 'Ok', value: undefined };
   }
 
   /**
@@ -215,7 +209,14 @@ export class SubscriptionHandleImpl<
     onEnd: (
       ctx: SubscriptionEventContextInterface<DBView, Reducers, SetReducerFlags>
     ) => void
-  ): Result {
+  ): void {
+    if (this.#endedState) {
+      throw new Error('Subscription has already ended');
+    }
+    if (this.#unsubscribeCalled) {
+      throw new Error('Unsubscribe has already been called');
+    }
+    this.#unsubscribeCalled = true;
     this.#emitter.on(
       'end',
       (
@@ -230,7 +231,6 @@ export class SubscriptionHandleImpl<
         onEnd(ctx);
       }
     );
-    return { tag: 'Ok', value: undefined };
   }
 
   /**

packages/sdk/tests/db_connection.test.ts

@@ -11,7 +11,11 @@ import { AlgebraicType } from '../src/algebraic_type';
 import { parseValue } from '../src/algebraic_value';
 import BinaryWriter from '../src/binary_writer';
 import * as ws from '../src/client_api';
-import { ReducerEvent, TimeDuration, Timestamp } from '../src/db_connection_impl';
+import {
+  ReducerEvent,
+  TimeDuration,
+  Timestamp,
+} from '../src/db_connection_impl';
 import { Identity } from '../src/identity';
 import WebsocketTestAdapter from '../src/websocket_test_adapter';
 
@@ -617,7 +621,7 @@ describe('DBConnection', () => {
             ],
           },
         ],
-    }),
+      }),
       timestamp: new Timestamp(BigInt(1681391805281203)),
       callerIdentity: anIdentity,
       callerAddress: Address.random(),