[TS] Throw error objects from syscalls (#4260)

# Description of Changes

This lets us avoid the try/catch around every syscall in javascript.

# API and ABI breaking changes

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corresponding GitHub label. -->

# Expected complexity level and risk

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# Testing

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Author: coolreader18

crates/bindings-typescript/src/server/errors.ts

@@ -1,33 +1,13 @@
 /**
  * Base class for all Spacetime host errors (i.e. errors that may be thrown
  * by database functions).
- *
- * Instances of SpacetimeError can be created with just an error code,
- * which will return the appropriate subclass instance.
  */
 export class SpacetimeHostError extends Error {
-  public readonly code: number;
-  public readonly message: string;
-  constructor(code: number, message?: string) {
-    super();
-    const proto = Object.getPrototypeOf(this);
-    let cls;
-    if (errorProtoypes.has(proto)) {
-      cls = proto.constructor;
-      if (code !== cls.CODE)
-        throw new TypeError(`invalid error code for ${cls.name}`);
-    } else if (proto === SpacetimeHostError.prototype) {
-      cls = errnoToClass.get(code);
-      if (!cls) throw new RangeError(`unknown error code ${code}`);
-    } else {
-      throw new TypeError('cannot subclass SpacetimeError');
-    }
-    Object.setPrototypeOf(this, cls.prototype);
-    this.code = cls.CODE;
-    this.message = message ?? cls.MESSAGE;
+  constructor(message: string) {
+    super(message);
   }
   get name(): string {
-    return errnoToClass.get(this.code)?.name ?? 'SpacetimeHostError';
+    return 'SpacetimeHostError';
   }
 }
 
@@ -50,110 +30,89 @@ const errorData = {
   /**
    * A generic error class for unknown error codes.
    */
-  HostCallFailure: [1, 'ABI called by host returned an error'],
+  HostCallFailure: 1,
 
   /**
    * Error indicating that an ABI call was made outside of a transaction.
    */
-  NotInTransaction: [2, 'ABI call can only be made while in a transaction'],
+  NotInTransaction: 2,
 
   /**
    * Error indicating that BSATN decoding failed.
    * This typically means that the data could not be decoded to the expected type.
    */
-  BsatnDecodeError: [3, "Couldn't decode the BSATN to the expected type"],
+  BsatnDecodeError: 3,
 
   /**
    * Error indicating that a specified table does not exist.
    */
-  NoSuchTable: [4, 'No such table'],
+  NoSuchTable: 4,
 
   /**
    * Error indicating that a specified index does not exist.
    */
-  NoSuchIndex: [5, 'No such index'],
+  NoSuchIndex: 5,
 
   /**
    * Error indicating that a specified row iterator is not valid.
    */
-  NoSuchIter: [6, 'The provided row iterator is not valid'],
+  NoSuchIter: 6,
 
   /**
    * Error indicating that a specified console timer does not exist.
    */
-  NoSuchConsoleTimer: [7, 'The provided console timer does not exist'],
+  NoSuchConsoleTimer: 7,
 
   /**
    * Error indicating that a specified bytes source or sink is not valid.
    */
-  NoSuchBytes: [8, 'The provided bytes source or sink is not valid'],
+  NoSuchBytes: 8,
 
   /**
    * Error indicating that a provided sink has no more space left.
    */
-  NoSpace: [9, 'The provided sink has no more space left'],
+  NoSpace: 9,
 
   /**
    * Error indicating that there is no more space in the database.
    */
-  BufferTooSmall: [
-    11,
-    'The provided buffer is not large enough to store the data',
-  ],
+  BufferTooSmall: 11,
 
   /**
    * Error indicating that a value with a given unique identifier already exists.
    */
-  UniqueAlreadyExists: [
-    12,
-    'Value with given unique identifier already exists',
-  ],
+  UniqueAlreadyExists: 12,
 
   /**
    * Error indicating that the specified delay in scheduling a row was too long.
    */
-  ScheduleAtDelayTooLong: [
-    13,
-    'Specified delay in scheduling row was too long',
-  ],
+  ScheduleAtDelayTooLong: 13,
 
   /**
    * Error indicating that an index was not unique when it was expected to be.
    */
-  IndexNotUnique: [14, 'The index was not unique'],
+  IndexNotUnique: 14,
 
   /**
    * Error indicating that an index was not unique when it was expected to be.
    */
-  NoSuchRow: [15, 'The row was not found, e.g., in an update call'],
+  NoSuchRow: 15,
 
   /**
    * Error indicating that an auto-increment sequence has overflowed.
    */
-  AutoIncOverflow: [16, 'The auto-increment sequence overflowed'],
+  AutoIncOverflow: 16,
 
-  WouldBlockTransaction: [
-    17,
-    'Attempted async or blocking op while holding open a transaction',
-  ],
+  WouldBlockTransaction: 17,
 
-  TransactionNotAnonymous: [
-    18,
-    'Not in an anonymous transaction. Called by a reducer?',
-  ],
+  TransactionNotAnonymous: 18,
 
-  TransactionIsReadOnly: [
-    19,
-    'ABI call can only be made while within a mutable transaction',
-  ],
+  TransactionIsReadOnly: 19,
 
-  TransactionIsMut: [
-    20,
-    'ABI call can only be made while within a read-only transaction',
-  ],
+  TransactionIsMut: 20,
 
-  HttpError: [21, 'The HTTP request failed'],
-} as const;
+  HttpError: 21,
+};
 
 function mapEntries<const T extends Record<string, any>, U>(
   x: T,
@@ -164,30 +123,27 @@ function mapEntries<const T extends Record<string, any>, U>(
   ) as any;
 }
 
+/**
+ * Map from error codes to their corresponding SpacetimeError subclass.
+ */
+const errnoToClass = new Map<number, new (msg: string) => Error>();
+
 export const errors = Object.freeze(
-  mapEntries(errorData, (name, [code, message]) =>
-    Object.defineProperty(
+  mapEntries(errorData, (name, code) => {
+    const cls = Object.defineProperty(
       class extends SpacetimeHostError {
-        static CODE = code;
-        static MESSAGE = message;
-        constructor() {
-          super(code);
+        get name() {
+          return name;
         }
       },
       'name',
       { value: name, writable: false }
-    )
-  )
+    );
+    errnoToClass.set(code, cls);
+    return cls;
+  })
 );
 
-/**
- * Set of prototypes of all SpacetimeError subclasses for quick lookup.
- */
-const errorProtoypes = new Set(Object.values(errors).map(cls => cls.prototype));
-
-/**
- * Map from error codes to their corresponding SpacetimeError subclass.
- */
-const errnoToClass = new Map(
-  Object.values(errors).map(cls => [cls.CODE as number, cls])
-);
+export function getErrorConstructor(code: number): new (msg: string) => Error {
+  return errnoToClass.get(code) ?? SpacetimeHostError;
+}

crates/bindings-typescript/src/server/runtime.ts

@@ -36,15 +36,15 @@ import { hasOwn, toCamelCase } from '../lib/util';
 import { type AnonymousViewCtx, type ViewCtx } from './views';
 import { isRowTypedQuery, makeQueryBuilder, toSql } from './query';
 import type { DbView } from './db_view';
-import { SenderError, SpacetimeHostError } from './errors';
+import { getErrorConstructor, SenderError } from './errors';
 import { Range, type Bound } from './range';
 import ViewResultHeader from '../lib/autogen/view_result_header_type';
 import { makeRandom, type Random } from './rng';
 import type { SchemaInner } from './schema';
 
 const { freeze } = Object;
 
-export const sys = freeze(wrapSyscalls(_syscalls2_0));
+export const sys = _syscalls2_0;
 
 export function parseJsonObject(json: string): JsonObject {
   let value: unknown;
@@ -312,13 +312,21 @@ class ModuleHooksImpl implements ModuleHooks {
     return writer.getBuffer();
   }
 
+  __get_error_constructor__(code: number): new (msg: string) => Error {
+    return getErrorConstructor(code);
+  }
+
+  get __sender_error_class__() {
+    return SenderError;
+  }
+
   __call_reducer__(
     reducerId: u32,
     sender: u256,
     connId: u128,
     timestamp: bigint,
     argsBuf: DataView
-  ): undefined | { tag: 'err'; value: string } {
+  ): void {
     const moduleCtx = this.#schema;
     const deserializeArgs = this.#reducerArgsDeserializers[reducerId];
     BINARY_READER.reset(argsBuf);
@@ -331,14 +339,7 @@ class ModuleHooksImpl implements ModuleHooks {
       new Timestamp(timestamp),
       ConnectionId.nullIfZero(new ConnectionId(connId))
     );
-    try {
-      callUserFunction(moduleCtx.reducers[reducerId], ctx, args);
-    } catch (e) {
-      if (e instanceof SenderError) {
-        return { tag: 'err', value: e.message };
-      }
-      throw e;
-    }
+    callUserFunction(moduleCtx.reducers[reducerId], ctx, args);
   }
 
   __call_view__(
@@ -906,51 +907,6 @@ class IteratorHandle implements Disposable {
   }
 }
 
-type Intersections<Ts extends readonly any[]> = Ts extends [
-  infer T,
-  ...infer Rest,
-]
-  ? T & Intersections<Rest>
-  : unknown;
-
-function wrapSyscalls<
-  Modules extends Record<string, symbol | ((...args: any[]) => any)>[],
->(...modules: Modules): Intersections<Modules> {
-  return Object.fromEntries(
-    modules
-      .flatMap(Object.entries)
-      .map(([k, v]) => [k, typeof v === 'function' ? wrapSyscall(v) : v])
-  ) as Intersections<Modules>;
-}
-
-function wrapSyscall<F extends (...args: any[]) => any>(
-  func: F
-): (...args: Parameters<F>) => ReturnType<F> {
-  const name = func.name;
-  return {
-    [name](...args: Parameters<F>) {
-      try {
-        return func(...args);
-      } catch (e) {
-        if (
-          e !== null &&
-          typeof e === 'object' &&
-          hasOwn(e, '__code_error__') &&
-          typeof e.__code_error__ == 'number'
-        ) {
-          const message =
-            hasOwn(e, '__error_message__') &&
-            typeof e.__error_message__ === 'string'
-              ? e.__error_message__
-              : undefined;
-          throw new SpacetimeHostError(e.__code_error__, message);
-        }
-        throw e;
-      }
-    },
-  }[name];
-}
-
 function fmtLog(...data: any[]) {
   return data.join(' ');
 }

crates/bindings-typescript/src/server/sys.d.ts

@@ -15,13 +15,16 @@ declare module 'spacetime:sys@2.0' {
   export interface ModuleHooks {
     __describe_module__(): Uint8Array;
 
+    __get_error_constructor__(code: number): new (msg: string) => Error;
+    __sender_error_class__: new (msg: string) => Error;
+
     __call_reducer__(
       reducerId: u32,
       sender: u256,
       connId: u128,
       timestamp: bigint,
       argsBuf: DataView
-    ): undefined | { tag: 'ok' } | { tag: 'err'; value: string };
+    ): void;
 
     __call_view__(id: u32, sender: u256, args: Uint8Array): Uint8Array | object;
 

crates/core/src/host/v8/builtins/mod.rs

@@ -5,7 +5,7 @@ use super::error::{exception_already_thrown, ExcResult, StringTooLongError, Thro
 use super::string::{str_from_ident, StringConst};
 use super::{FnRet, IntoJsString};
 
-pub(super) fn evalute_builtins(scope: &mut PinScope<'_, '_>) -> ExcResult<()> {
+pub(super) fn evaluate_builtins(scope: &mut PinScope<'_, '_>) -> ExcResult<()> {
     macro_rules! eval_builtin {
         ($file:literal) => {
             eval_builtin(