feat: Isomorphic mutators

.gitignore

@@ -0,0 +1 @@
+node_modules

backend/package.json

@@ -12,17 +12,24 @@
     "generate-types": "openapi-typescript ../openapi.yaml -o src/generated/api.ts"
   },
   "dependencies": {
+    "@write-api/shared": "workspace:*",
     "dotenv": "^16.3.1",
+    "drizzle-orm": "0.45.2",
     "express": "^4.18.2",
     "express-openapi-validator": "^5.6.2",
     "jose": "^5.3.0",
     "mongodb": "^6.9.0",
     "mssql": "^12.1.0",
-    "mysql2": "^3.11.3",
+    "mysql2": "3.11.3",
     "pg": "^8.11.3",
     "winston": "^3.11.0",
     "zod": "^4.4.3"
   },
+  "dependenciesMeta": {
+    "@write-api/shared": {
+      "injected": true
+    }
+  },
   "devDependencies": {
     "@types/express": "^5.0.6",
     "@types/mssql": "^9.1.8",

backend/src/mutators/router.ts

@@ -1,12 +1,13 @@
 import express, { type Request, type Response } from 'express';
 import PG from 'pg';
+import { drizzle } from 'drizzle-orm/node-postgres';
 import { z } from 'zod';
 import { URL } from 'url';
 import config from '../../config.js';
 import { FatalOperationError, RetryableError } from '../errors.js';
 import type { OpBody, OpResponse } from '../types.js';
-import { serverMutators } from './mutators.js';
-import type { ServerMutator } from './types.js';
+import { sharedMutators, type Mutator } from '@write-api/shared/mutators';
+import * as pgSchema from '@write-api/shared/schema/todos.pg';
 
 const { Pool } = PG;
 
@@ -39,20 +40,62 @@ if (config.database.type !== 'postgres') {
     console.error('Pool connection failure to postgres (mutators):', err);
   });
 
+  const drizzleDb = drizzle(pool, { schema: pgSchema });
+
+  // Map an error to the response shape.
+  const sendPgError = (res: Response<OpResponse<'invokeMutator'>>, e: unknown): void => {
+    if (e instanceof FatalOperationError) {
+      res.status(200).send({
+        status: 'fatal_error',
+        message: e.message,
+        failed_operation: { error_code: e.errorCode, message: e.message }
+      });
+      return;
+    }
+    if (e instanceof RetryableError) {
+      res.status(200).send({ status: 'retryable_error', message: e.message });
+      return;
+    }
+    const err = e as Error & { code?: string };
+    const code = err.code ?? '';
+    if (code === '23505') {
+      res.status(200).send({
+        status: 'fatal_error',
+        message: err.message,
+        failed_operation: { error_code: 'UNIQUE_VIOLATION', message: err.message }
+      });
+    } else if (code === '23503') {
+      res.status(200).send({
+        status: 'fatal_error',
+        message: err.message,
+        failed_operation: { error_code: 'FOREIGN_KEY_VIOLATION', message: err.message }
+      });
+    } else if (code.startsWith('42')) {
+      res.status(200).send({
+        status: 'fatal_error',
+        message: err.message,
+        failed_operation: { error_code: 'SCHEMA_MISMATCH', message: err.message }
+      });
+    } else {
+      res.status(200).send({ status: 'retryable_error', message: err.message });
+    }
+  };
+
   router.post(
     '/invoke',
     async (
       req: Request<{}, OpResponse<'invokeMutator'>, OpBody<'invokeMutator'>>,
       res: Response<OpResponse<'invokeMutator'>>
     ) => {
       const { name, args: rawArgs } = req.body;
-      const mutator = (serverMutators as Record<string, ServerMutator>)[name];
 
+      // Same shared definition the client runs, applied to Postgres via Drizzle.
+      const mutator = (sharedMutators as Record<string, Mutator>)[name];
       if (!mutator) {
         res.status(200).send({
           status: 'fatal_error',
           message: `Unknown mutator "${name}"`,
-          failed_operation: { error_code: 'UNKNOWN_MUTATOR', message: `No server-side handler registered for mutator "${name}".` }
+          failed_operation: { error_code: 'UNKNOWN_MUTATOR', message: `No handler registered for mutator "${name}".` }
         });
         return;
       }
@@ -74,51 +117,13 @@ if (config.database.type !== 'postgres') {
       // token's sub, never from the request body.
       const userId = req.auth!.sub;
 
-      const client = await pool.connect();
       try {
-        await client.query('BEGIN');
-        await mutator.run(parsedArgs, { userId, pg: client });
-        await client.query('COMMIT');
+        await drizzleDb.transaction(async (tx) => {
+          await mutator.run(parsedArgs, { tx, schema: pgSchema, userId });
+        });
         res.status(200).send({ status: 'success', message: `Mutator "${name}" applied` });
       } catch (e) {
-        await client.query('ROLLBACK');
-        if (e instanceof FatalOperationError) {
-          res.status(200).send({
-            status: 'fatal_error',
-            message: e.message,
-            failed_operation: { error_code: e.errorCode, message: e.message }
-          });
-          return;
-        }
-        if (e instanceof RetryableError) {
-          res.status(200).send({ status: 'retryable_error', message: e.message });
-          return;
-        }
-        const err = e as Error & { code?: string };
-        const code = err.code ?? '';
-        if (code === '23505') {
-          res.status(200).send({
-            status: 'fatal_error',
-            message: err.message,
-            failed_operation: { error_code: 'UNIQUE_VIOLATION', message: err.message }
-          });
-        } else if (code === '23503') {
-          res.status(200).send({
-            status: 'fatal_error',
-            message: err.message,
-            failed_operation: { error_code: 'FOREIGN_KEY_VIOLATION', message: err.message }
-          });
-        } else if (code.startsWith('42')) {
-          res.status(200).send({
-            status: 'fatal_error',
-            message: err.message,
-            failed_operation: { error_code: 'SCHEMA_MISMATCH', message: err.message }
-          });
-        } else {
-          res.status(200).send({ status: 'retryable_error', message: err.message });
-        }
-      } finally {
-        client.release();
+        sendPgError(res, e);
       }
     }
   );

frontend/package.json

@@ -13,13 +13,16 @@
     "@emotion/react": "^11.11.4",
     "@emotion/styled": "^11.11.5",
     "@esbuild-plugins/node-globals-polyfill": "^0.2.3",
-    "@journeyapps/wa-sqlite": "latest",
+    "@journeyapps/wa-sqlite": "1.7.0",
     "@mui/icons-material": "^5.15.15",
     "@mui/material": "^5.15.12",
     "@mui/x-data-grid": "^6.19.6",
-    "@powersync/react": "latest",
-    "@powersync/web": "latest",
+    "@powersync/drizzle-driver": "0.7.4",
+    "@powersync/react": "1.10.0",
+    "@powersync/web": "1.37.2",
     "@supabase/supabase-js": "^2.39.7",
+    "@write-api/shared": "workspace:*",
+    "drizzle-orm": "0.45.2",
     "js-logger": "^1.6.1",
     "lodash": "^4.17.21",
     "openapi-fetch": "^0.17.0",
@@ -29,6 +32,11 @@
     "uuid": "^9.0.1",
     "zod": "^4.4.3"
   },
+  "dependenciesMeta": {
+    "@write-api/shared": {
+      "injected": true
+    }
+  },
   "devDependencies": {
     "@types/lodash": "^4.14.202",
     "@types/node": "^20.11.25",