chore: changeset

.changeset/selfish-llamas-pump.md

@@ -0,0 +1,8 @@
+---
+"cojson-storage-indexeddb": patch
+"cojson-storage-rn-sqlite": patch
+"cojson-storage-sqlite": patch
+"cojson-storage": patch
+---
+
+Improve rollback on error when failing to add new content

packages/cojson-storage-indexeddb/src/CoJsonIDBTransaction.ts

@@ -0,0 +1,111 @@
+export type StoreName =
+  | "coValues"
+  | "sessions"
+  | "transactions"
+  | "signatureAfter";
+
+// A access unit for the IndexedDB Jazz database
+// It's a wrapper around the IDBTransaction object that helps on batching multiple operations
+// in a single transaction.
+export class CoJsonIDBTransaction {
+  db: IDBDatabase;
+  tx: IDBTransaction;
+
+  pendingRequests: ((txEntry: this) => void)[] = [];
+  rejectHandlers: (() => void)[] = [];
+
+  id = Math.random();
+
+  running = false;
+  failed = false;
+  done = false;
+
+  constructor(db: IDBDatabase) {
+    this.db = db;
+
+    this.tx = this.db.transaction(
+      ["coValues", "sessions", "transactions", "signatureAfter"],
+      "readwrite",
+    );
+
+    this.tx.oncomplete = () => {
+      this.done = true;
+    };
+    this.tx.onabort = () => {
+      this.done = true;
+    };
+  }
+
+  startedAt = performance.now();
+  isReusable() {
+    const delta = performance.now() - this.startedAt;
+    return !this.done && delta <= 20;
+  }
+
+  getObjectStore(name: StoreName) {
+    return this.tx.objectStore(name);
+  }
+
+  private pushRequest<T>(
+    handler: (txEntry: this, next: () => void) => Promise<T>,
+  ) {
+    const next = () => {
+      const next = this.pendingRequests.shift();
+
+      if (next) {
+        next(this);
+      } else {
+        this.running = false;
+        this.done = true;
+      }
+    };
+
+    if (this.running) {
+      return new Promise<T>((resolve, reject) => {
+        this.rejectHandlers.push(reject);
+        this.pendingRequests.push(async () => {
+          try {
+            const result = await handler(this, next);
+            resolve(result);
+          } catch (error) {
+            reject(error);
+          }
+        });
+      });
+    }
+
+    this.running = true;
+    return handler(this, next);
+  }
+
+  handleRequest<T>(handler: (txEntry: this) => IDBRequest<T>) {
+    return this.pushRequest<T>((txEntry, next) => {
+      return new Promise<T>((resolve, reject) => {
+        const request = handler(txEntry);
+
+        request.onerror = () => {
+          this.failed = true;
+          this.tx.abort();
+          console.error(request.error);
+          reject(request.error);
+
+          // Don't leave any pending promise
+          for (const handler of this.rejectHandlers) {
+            handler();
+          }
+        };
+
+        request.onsuccess = () => {
+          resolve(request.result as T);
+          next();
+        };
+      });
+    });
+  }
+
+  commit() {
+    if (!this.done) {
+      this.tx.commit();
+    }
+  }
+}

packages/cojson-storage-indexeddb/src/idbClient.ts

@@ -1,4 +1,4 @@
-import type { CojsonInternalTypes, RawCoID } from "cojson";
+import type { CojsonInternalTypes, RawCoID, SessionID } from "cojson";
 import type {
   CoValueRow,
   DBClientInterface,
@@ -8,119 +8,60 @@ import type {
   StoredSessionRow,
   TransactionRow,
 } from "cojson-storage";
-import { SyncPromise } from "./syncPromises.js";
+import { CoJsonIDBTransaction } from "./CoJsonIDBTransaction.js";
 
 export class IDBClient implements DBClientInterface {
   private db;
 
-  currentTx:
-    | {
-        id: number;
-        tx: IDBTransaction;
-        stores: {
-          coValues: IDBObjectStore;
-          sessions: IDBObjectStore;
-          transactions: IDBObjectStore;
-          signatureAfter: IDBObjectStore;
-        };
-        startedAt: number;
-        pendingRequests: ((txEntry: {
-          stores: {
-            coValues: IDBObjectStore;
-            sessions: IDBObjectStore;
-            transactions: IDBObjectStore;
-            signatureAfter: IDBObjectStore;
-          };
-        }) => void)[];
-      }
-    | undefined;
-
-  currentTxID = 0;
+  activeTransaction: CoJsonIDBTransaction | undefined;
+  autoBatchingTransaction: CoJsonIDBTransaction | undefined;
 
   constructor(db: IDBDatabase) {
     this.db = db;
   }
 
   makeRequest<T>(
-    handler: (stores: {
-      coValues: IDBObjectStore;
-      sessions: IDBObjectStore;
-      transactions: IDBObjectStore;
-      signatureAfter: IDBObjectStore;
-    }) => IDBRequest,
-  ): SyncPromise<T> {
-    return new SyncPromise((resolve, reject) => {
-      let txEntry = this.currentTx;
+    handler: (txEntry: CoJsonIDBTransaction) => IDBRequest<T>,
+  ): Promise<T> {
+    if (this.activeTransaction) {
+      return this.activeTransaction.handleRequest<T>(handler);
+    }
 
-      const requestEntry = ({
-        stores,
-      }: {
-        stores: {
-          coValues: IDBObjectStore;
-          sessions: IDBObjectStore;
-          transactions: IDBObjectStore;
-          signatureAfter: IDBObjectStore;
-        };
-      }) => {
-        const request = handler(stores);
-        request.onerror = () => {
-          console.error("Error in request", request.error);
-          this.currentTx = undefined;
-          reject(request.error);
-        };
-        request.onsuccess = () => {
-          const value = request.result as T;
-          resolve(value);
+    if (this.autoBatchingTransaction?.isReusable()) {
+      return this.autoBatchingTransaction.handleRequest<T>(handler);
+    }
 
-          const next = txEntry?.pendingRequests.shift();
+    const tx = new CoJsonIDBTransaction(this.db);
 
-          if (next) {
-            next({ stores });
-          } else {
-            if (this.currentTx === txEntry) {
-              this.currentTx = undefined;
-            }
-          }
-        };
-      };
+    this.autoBatchingTransaction = tx;
 
-      // Transaction batching
-      if (!txEntry || performance.now() - txEntry.startedAt > 20) {
-        const tx = this.db.transaction(
-          ["coValues", "sessions", "transactions", "signatureAfter"],
-          "readwrite",
-        );
-        txEntry = {
-          id: this.currentTxID++,
-          tx,
-          stores: {
-            coValues: tx.objectStore("coValues"),
-            sessions: tx.objectStore("sessions"),
-            transactions: tx.objectStore("transactions"),
-            signatureAfter: tx.objectStore("signatureAfter"),
-          },
-          startedAt: performance.now(),
-          pendingRequests: [],
-        };
-
-        this.currentTx = txEntry;
-
-        requestEntry(txEntry);
-      } else {
-        txEntry.pendingRequests.push(requestEntry);
-      }
-    });
+    return tx.handleRequest<T>(handler);
   }
 
   async getCoValue(coValueId: RawCoID): Promise<StoredCoValueRow | undefined> {
-    return this.makeRequest<StoredCoValueRow | undefined>(({ coValues }) =>
-      coValues.index("coValuesById").get(coValueId),
+    return this.makeRequest<StoredCoValueRow | undefined>((tx) =>
+      tx.getObjectStore("coValues").index("coValuesById").get(coValueId),
     );
   }
 
   async getCoValueSessions(coValueRowId: number): Promise<StoredSessionRow[]> {
-    return this.makeRequest<StoredSessionRow[]>(({ sessions }) =>
-      sessions.index("sessionsByCoValue").getAll(coValueRowId),
+    return this.makeRequest<StoredSessionRow[]>((tx) =>
+      tx
+        .getObjectStore("sessions")
+        .index("sessionsByCoValue")
+        .getAll(coValueRowId),
+    );
+  }
+
+  async getSingleCoValueSession(
+    coValueRowId: number,
+    sessionID: SessionID,
+  ): Promise<StoredSessionRow | undefined> {
+    return this.makeRequest<StoredSessionRow>((tx) =>
+      tx
+        .getObjectStore("sessions")
+        .index("uniqueSessions")
+        .get([coValueRowId, sessionID]),
     );
   }
 
@@ -128,13 +69,15 @@ export class IDBClient implements DBClientInterface {
     sessionRowId: number,
     firstNewTxIdx: number,
   ): Promise<TransactionRow[]> {
-    return this.makeRequest<TransactionRow[]>(({ transactions }) =>
-      transactions.getAll(
-        IDBKeyRange.bound(
-          [sessionRowId, firstNewTxIdx],
-          [sessionRowId, Number.POSITIVE_INFINITY],
+    return this.makeRequest<TransactionRow[]>((tx) =>
+      tx
+        .getObjectStore("transactions")
+        .getAll(
+          IDBKeyRange.bound(
+            [sessionRowId, firstNewTxIdx],
+            [sessionRowId, Number.POSITIVE_INFINITY],
+          ),
         ),
-      ),
     );
   }
 
@@ -142,9 +85,10 @@ export class IDBClient implements DBClientInterface {
     sessionRowId: number,
     firstNewTxIdx: number,
   ): Promise<SignatureAfterRow[]> {
-    return this.makeRequest<SignatureAfterRow[]>(
-      ({ signatureAfter }: { signatureAfter: IDBObjectStore }) =>
-        signatureAfter.getAll(
+    return this.makeRequest<SignatureAfterRow[]>((tx) =>
+      tx
+        .getObjectStore("signatureAfter")
+        .getAll(
           IDBKeyRange.bound(
             [sessionRowId, firstNewTxIdx],
             [sessionRowId, Number.POSITIVE_INFINITY],
@@ -160,8 +104,8 @@ export class IDBClient implements DBClientInterface {
       throw new Error(`Header is required, coId: ${msg.id}`);
     }
 
-    return (await this.makeRequest<IDBValidKey>(({ coValues }) =>
-      coValues.put({
+    return (await this.makeRequest<IDBValidKey>((tx) =>
+      tx.getObjectStore("coValues").put({
         id: msg.id,
         // biome-ignore lint/style/noNonNullAssertion: TODO(JAZZ-561): Review
         header: msg.header!,
@@ -176,25 +120,26 @@ export class IDBClient implements DBClientInterface {
     sessionUpdate: SessionRow;
     sessionRow?: StoredSessionRow;
   }): Promise<number> {
-    return this.makeRequest<number>(({ sessions }) =>
-      sessions.put(
-        sessionRow?.rowID
-          ? {
-              rowID: sessionRow.rowID,
-              ...sessionUpdate,
-            }
-          : sessionUpdate,
-      ),
+    return this.makeRequest<number>(
+      (tx) =>
+        tx.getObjectStore("sessions").put(
+          sessionRow?.rowID
+            ? {
+                rowID: sessionRow.rowID,
+                ...sessionUpdate,
+              }
+            : sessionUpdate,
+        ) as IDBRequest<number>,
     );
   }
 
-  addTransaction(
+  async addTransaction(
     sessionRowID: number,
     idx: number,
     newTransaction: CojsonInternalTypes.Transaction,
   ) {
-    return this.makeRequest(({ transactions }) =>
-      transactions.add({
+    await this.makeRequest((tx) =>
+      tx.getObjectStore("transactions").add({
         ses: sessionRowID,
         idx,
         tx: newTransaction,
@@ -211,8 +156,8 @@ export class IDBClient implements DBClientInterface {
     idx: number;
     signature: CojsonInternalTypes.Signature;
   }) {
-    return this.makeRequest(({ signatureAfter }) =>
-      signatureAfter.put({
+    return this.makeRequest((tx) =>
+      tx.getObjectStore("signatureAfter").put({
         ses: sessionRowID,
         idx,
         signature,
@@ -220,7 +165,24 @@ export class IDBClient implements DBClientInterface {
     );
   }
 
-  async unitOfWork(operationsCallback: () => unknown[]) {
-    return Promise.all(operationsCallback());
+  closeTransaction(tx: CoJsonIDBTransaction) {
+    tx.commit();
+
+    if (tx === this.activeTransaction) {
+      this.activeTransaction = undefined;
+    }
+  }
+
+  async transaction(operationsCallback: () => unknown) {
+    const tx = new CoJsonIDBTransaction(this.db);
+
+    this.activeTransaction = tx;
+
+    try {
+      await operationsCallback();
+      tx.commit(); // Tells the browser to not wait for another possible request and commit the transaction immediately
+    } finally {
+      this.activeTransaction = undefined;
+    }
   }
 }

packages/cojson-storage-indexeddb/src/idbNode.ts

@@ -33,18 +33,7 @@ export class IDBNode {
           }
           await this.syncManager.handleSyncMessage(msg);
         } catch (e) {
-          console.error(
-            new Error(
-              `Error reading from localNode, handling msg\n\n${JSON.stringify(
-                msg,
-                (k, v) =>
-                  k === "changes" || k === "encryptedChanges"
-                    ? `${v.slice(0, 20)}...`
-                    : v,
-              )}`,
-              { cause: e },
-            ),
-          );
+          console.error(e);
         }
       }
     };

packages/cojson-storage-indexeddb/src/syncPromises.ts

@@ -1,224 +0,0 @@
-const isFunction = (func: any) => typeof func === "function";
-
-const isObject = (supposedObject: any) =>
-  typeof supposedObject === "object" &&
-  supposedObject !== null &&
-  !Array.isArray(supposedObject);
-
-const isThenable = (obj: any) => isObject(obj) && isFunction(obj.then);
-
-const identity = (co: any) => co;
-
-export { identity, isFunction, isObject, isThenable };
-
-enum States {
-  PENDING = "PENDING",
-  RESOLVED = "RESOLVED",
-  REJECTED = "REJECTED",
-}
-
-interface Handler<T, U> {
-  onSuccess: HandlerOnSuccess<T, U>;
-  onFail: HandlerOnFail<U>;
-}
-
-type HandlerOnSuccess<T, U = any> = (value: T) => U | Thenable<U>;
-type HandlerOnFail<U = any> = (reason: any) => U | Thenable<U>;
-type Finally<U> = () => U | Thenable<U>;
-
-interface Thenable<T> {
-  then<U>(
-    onSuccess?: HandlerOnSuccess<T, U>,
-    onFail?: HandlerOnFail<U>,
-  ): Thenable<U>;
-  then<U>(
-    onSuccess?: HandlerOnSuccess<T, U>,
-    onFail?: (reason: any) => void,
-  ): Thenable<U>;
-}
-
-type Resolve<R> = (value?: R | Thenable<R>) => void;
-type Reject = (value?: any) => void;
-
-export class SyncPromise<T> {
-  private state: States = States.PENDING;
-  private handlers: Handler<T, any>[] = [];
-  private value: T | any;
-
-  public constructor(callback: (resolve: Resolve<T>, reject: Reject) => void) {
-    try {
-      callback(this.resolve as Resolve<T>, this.reject);
-    } catch (e) {
-      this.reject(e);
-    }
-  }
-
-  private resolve = (value: T) => {
-    return this.setResult(value, States.RESOLVED);
-  };
-
-  private reject = (reason: any) => {
-    return this.setResult(reason, States.REJECTED);
-  };
-
-  private setResult = (value: T | any, state: States) => {
-    const set = () => {
-      if (this.state !== States.PENDING) {
-        return null;
-      }
-
-      if (isThenable(value)) {
-        return (value as Thenable<T>).then(this.resolve, this.reject);
-      }
-
-      this.value = value;
-      this.state = state;
-
-      return this.executeHandlers();
-    };
-
-    void set();
-  };
-
-  private executeHandlers = () => {
-    if (this.state === States.PENDING) {
-      return null;
-    }
-
-    for (const handler of this.handlers) {
-      if (this.state === States.REJECTED) {
-        handler.onFail(this.value);
-      } else {
-        handler.onSuccess(this.value);
-      }
-    }
-
-    this.handlers = [];
-  };
-
-  private attachHandler = (handler: Handler<T, any>) => {
-    this.handlers = [...this.handlers, handler];
-
-    this.executeHandlers();
-  };
-
-  // biome-ignore lint/suspicious/noThenProperty: TODO(JAZZ-561): Review
-  public then<U>(onSuccess: HandlerOnSuccess<T, U>, onFail?: HandlerOnFail<U>) {
-    return new SyncPromise<U>((resolve, reject) => {
-      return this.attachHandler({
-        onSuccess: (result) => {
-          try {
-            return resolve(onSuccess(result));
-          } catch (e) {
-            return reject(e);
-          }
-        },
-        onFail: (reason) => {
-          if (!onFail) {
-            return reject(reason);
-          }
-
-          try {
-            return resolve(onFail(reason));
-          } catch (e) {
-            return reject(e);
-          }
-        },
-      });
-    });
-  }
-
-  public catch<U>(onFail: HandlerOnFail<U>) {
-    return this.then<U>(identity, onFail);
-  }
-
-  // methods
-
-  public toString() {
-    return "[object SyncPromise]";
-  }
-
-  public finally<U>(cb: Finally<U>) {
-    return new SyncPromise<U>((resolve, reject) => {
-      let co: U | any;
-      let isRejected: boolean;
-
-      return this.then(
-        (value) => {
-          isRejected = false;
-          co = value;
-          return cb();
-        },
-        (reason) => {
-          isRejected = true;
-          co = reason;
-          return cb();
-        },
-      ).then(() => {
-        if (isRejected) {
-          return reject(co);
-        }
-
-        return resolve(co);
-      });
-    });
-  }
-
-  public spread<U>(handler: (...args: any[]) => U) {
-    return this.then<U>((collection) => {
-      if (Array.isArray(collection)) {
-        return handler(...collection);
-      }
-
-      return handler(collection);
-    });
-  }
-
-  // static
-
-  public static resolve<U = any>(value?: U | Thenable<U>) {
-    return new SyncPromise<U>((resolve) => {
-      return resolve(value);
-    });
-  }
-
-  public static reject<U>(reason?: any) {
-    return new SyncPromise<U>((_resolve, reject) => {
-      return reject(reason);
-    });
-  }
-
-  public static all<U = any>(collection: (U | Thenable<U>)[]) {
-    return new SyncPromise<U[]>((resolve, reject) => {
-      if (!Array.isArray(collection)) {
-        return reject(new TypeError("An array must be provided."));
-      }
-
-      if (collection.length === 0) {
-        return resolve([]);
-      }
-
-      let counter = collection.length;
-      const resolvedCollection: U[] = [];
-
-      const tryResolve = (value: U, index: number) => {
-        counter -= 1;
-        resolvedCollection[index] = value;
-
-        if (counter !== 0) {
-          return null;
-        }
-
-        return resolve(resolvedCollection);
-      };
-
-      return collection.forEach((item, index) => {
-        return SyncPromise.resolve(item)
-          .then((value) => {
-            return tryResolve(value, index);
-          })
-          .catch(reject);
-      });
-    });
-  }
-}

packages/cojson-storage-indexeddb/src/tests/CoJsonIDBTransaction.test.ts

@@ -0,0 +1,170 @@
+import { afterEach, beforeEach, describe, expect, test } from "vitest";
+import { CoJsonIDBTransaction } from "../CoJsonIDBTransaction";
+
+const TEST_DB_NAME = "test-cojson-idb-transaction";
+
+describe("CoJsonIDBTransaction", () => {
+  let db: IDBDatabase;
+
+  beforeEach(async () => {
+    // Create test database
+    await new Promise<void>((resolve, reject) => {
+      const request = indexedDB.open(TEST_DB_NAME, 1);
+
+      request.onerror = () => reject(request.error);
+
+      request.onupgradeneeded = (event) => {
+        const db = request.result;
+        // Create test stores
+        db.createObjectStore("coValues", { keyPath: "id" });
+        const sessions = db.createObjectStore("sessions", { keyPath: "id" });
+        sessions.createIndex("uniqueSessions", ["coValue", "sessionID"], {
+          unique: true,
+        });
+        db.createObjectStore("transactions", { keyPath: "id" });
+        db.createObjectStore("signatureAfter", { keyPath: "id" });
+      };
+
+      request.onsuccess = () => {
+        db = request.result;
+        resolve();
+      };
+    });
+  });
+
+  afterEach(async () => {
+    // Close and delete test database
+    db.close();
+    await new Promise<void>((resolve, reject) => {
+      const request = indexedDB.deleteDatabase(TEST_DB_NAME);
+      request.onerror = () => reject(request.error);
+      request.onsuccess = () => resolve();
+    });
+  });
+
+  test("handles successful write and read operations", async () => {
+    const tx = new CoJsonIDBTransaction(db);
+
+    // Write test
+    await tx.handleRequest((tx) =>
+      tx.getObjectStore("coValues").put({
+        id: "test1",
+        value: "hello",
+      }),
+    );
+
+    // Read test
+    const readTx = new CoJsonIDBTransaction(db);
+    const result = await readTx.handleRequest((tx) =>
+      tx.getObjectStore("coValues").get("test1"),
+    );
+
+    expect(result).toEqual({
+      id: "test1",
+      value: "hello",
+    });
+  });
+
+  test("handles multiple operations in single transaction", async () => {
+    const tx = new CoJsonIDBTransaction(db);
+
+    // Multiple writes
+    await Promise.all([
+      tx.handleRequest((tx) =>
+        tx.getObjectStore("coValues").put({
+          id: "test1",
+          value: "hello",
+        }),
+      ),
+      tx.handleRequest((tx) =>
+        tx.getObjectStore("coValues").put({
+          id: "test2",
+          value: "world",
+        }),
+      ),
+    ]);
+
+    // Read results
+    const readTx = new CoJsonIDBTransaction(db);
+    const [result1, result2] = await Promise.all([
+      readTx.handleRequest((tx) => tx.getObjectStore("coValues").get("test1")),
+      readTx.handleRequest((tx) => tx.getObjectStore("coValues").get("test2")),
+    ]);
+
+    expect(result1).toEqual({
+      id: "test1",
+      value: "hello",
+    });
+    expect(result2).toEqual({
+      id: "test2",
+      value: "world",
+    });
+  });
+
+  test("handles transaction across multiple stores", async () => {
+    const tx = new CoJsonIDBTransaction(db);
+
+    await Promise.all([
+      tx.handleRequest((tx) =>
+        tx.getObjectStore("coValues").put({
+          id: "value1",
+          data: "value data",
+        }),
+      ),
+      tx.handleRequest((tx) =>
+        tx.getObjectStore("sessions").put({
+          id: "session1",
+          data: "session data",
+        }),
+      ),
+    ]);
+
+    const readTx = new CoJsonIDBTransaction(db);
+    const [valueResult, sessionResult] = await Promise.all([
+      readTx.handleRequest((tx) => tx.getObjectStore("coValues").get("value1")),
+      readTx.handleRequest((tx) =>
+        tx.getObjectStore("sessions").get("session1"),
+      ),
+    ]);
+
+    expect(valueResult).toEqual({
+      id: "value1",
+      data: "value data",
+    });
+    expect(sessionResult).toEqual({
+      id: "session1",
+      data: "session data",
+    });
+  });
+
+  test("handles failed transactions", async () => {
+    const tx = new CoJsonIDBTransaction(db);
+
+    await expect(
+      tx.handleRequest((tx) =>
+        tx.getObjectStore("sessions").put({
+          id: 1,
+          coValue: "value1",
+          sessionID: "session1",
+          data: "session data",
+        }),
+      ),
+    ).resolves.toBe(1);
+
+    expect(tx.failed).toBe(false);
+
+    const badTx = new CoJsonIDBTransaction(db);
+    await expect(
+      badTx.handleRequest((tx) =>
+        tx.getObjectStore("sessions").put({
+          id: 2,
+          coValue: "value1",
+          sessionID: "session1",
+          data: "session data",
+        }),
+      ),
+    ).rejects.toThrow();
+
+    expect(badTx.failed).toBe(true);
+  });
+});

packages/cojson-storage-rn-sqlite/src/client.ts

@@ -1,5 +1,10 @@
 import { type DB as DatabaseT } from "@op-engineering/op-sqlite";
-import { CojsonInternalTypes, type OutgoingSyncQueue, RawCoID } from "cojson";
+import {
+  CojsonInternalTypes,
+  type OutgoingSyncQueue,
+  RawCoID,
+  SessionID,
+} from "cojson";
 import type {
   DBClientInterface,
   SessionRow,
@@ -48,6 +53,17 @@ export class SQLiteClient implements DBClientInterface {
     return rows as StoredSessionRow[];
   }
 
+  async getSingleCoValueSession(
+    coValueRowId: number,
+    sessionID: SessionID,
+  ): Promise<StoredSessionRow | undefined> {
+    const { rows } = await this.db.execute(
+      "SELECT * FROM sessions WHERE coValue = ? AND sessionID = ?",
+      [coValueRowId, sessionID],
+    );
+    return rows[0] as StoredSessionRow | undefined;
+  }
+
   async getNewTransactionInSession(
     sessionRowId: number,
     firstNewTxIdx: number,
@@ -142,12 +158,10 @@ export class SQLiteClient implements DBClientInterface {
     );
   }
 
-  async unitOfWork(
-    operationsCallback: () => Promise<unknown>[],
-  ): Promise<void> {
+  async transaction(operationsCallback: () => unknown) {
     try {
       await this.db.transaction(async () => {
-        await Promise.all(operationsCallback());
+        await operationsCallback();
       });
     } catch (e) {
       console.error("Transaction failed:", e);

packages/cojson-storage-sqlite/src/sqliteClient.ts

@@ -71,6 +71,17 @@ export class SQLiteClient implements DBClientInterface {
       .all(coValueRowId) as StoredSessionRow[];
   }
 
+  getSingleCoValueSession(
+    coValueRowId: number,
+    sessionID: SessionID,
+  ): StoredSessionRow | undefined {
+    return this.db
+      .prepare<[number, string]>(
+        `SELECT * FROM sessions WHERE coValue = ? AND sessionID = ?`,
+      )
+      .get(coValueRowId, sessionID) as StoredSessionRow | undefined;
+  }
+
   getNewTransactionInSession(
     sessionRowId: number,
     firstNewTxIdx: number,
@@ -159,7 +170,7 @@ export class SQLiteClient implements DBClientInterface {
       .run(sessionRowID, idx, signature);
   }
 
-  unitOfWork(operationsCallback: () => any[]) {
+  transaction(operationsCallback: () => unknown) {
     this.db.transaction(operationsCallback)();
   }
 }

packages/cojson-storage/src/syncManager.ts

@@ -200,15 +200,6 @@ export class SyncManager {
       ? coValueRow.rowID
       : await this.dbClient.addCoValue(msg);
 
-    const allOurSessionsEntries =
-      await this.dbClient.getCoValueSessions(storedCoValueRowID);
-
-    const allOurSessions: {
-      [sessionID: SessionID]: StoredSessionRow;
-    } = Object.fromEntries(
-      allOurSessionsEntries.map((row) => [row.sessionID, row]),
-    );
-
     const ourKnown: CojsonInternalTypes.CoValueKnownState = {
       id: msg.id,
       header: true,
@@ -217,9 +208,13 @@ export class SyncManager {
 
     let invalidAssumptions = false;
 
-    await this.dbClient.unitOfWork(() =>
-      (Object.keys(msg.new) as SessionID[]).map((sessionID) => {
-        const sessionRow = allOurSessions[sessionID];
+    for (const sessionID of Object.keys(msg.new) as SessionID[]) {
+      await this.dbClient.transaction(async () => {
+        const sessionRow = await this.dbClient.getSingleCoValueSession(
+          storedCoValueRowID,
+          sessionID,
+        );
+
         if (sessionRow) {
           ourKnown.sessions[sessionRow.sessionID] = sessionRow.lastIdx;
         }
@@ -229,8 +224,8 @@ export class SyncManager {
         } else {
           return this.putNewTxs(msg, sessionID, sessionRow, storedCoValueRowID);
         }
-      }),
-    );
+      });
+    }
 
     if (invalidAssumptions) {
       this.sendStateMessage({

packages/cojson-storage/src/tests/syncManager.test.ts

@@ -45,9 +45,11 @@ describe("DB sync manager", () => {
   const DBClient = vi.fn();
   DBClient.prototype.getCoValue = vi.fn();
   DBClient.prototype.getCoValueSessions = vi.fn();
+  DBClient.prototype.getSingleCoValueSession = vi.fn();
+  DBClient.prototype.getNewTransactionInSession = vi.fn();
   DBClient.prototype.addSessionUpdate = vi.fn();
   DBClient.prototype.addTransaction = vi.fn();
-  DBClient.prototype.unitOfWork = vi.fn((callback) => Promise.all(callback()));
+  DBClient.prototype.transaction = vi.fn((callback) => callback());
 
   beforeEach(async () => {
     const idbClient = new DBClient() as unknown as Mocked<DBClientInterface>;

packages/cojson-storage/src/types.ts

@@ -41,6 +41,11 @@ export interface DBClientInterface {
     coValueRowId: number,
   ): Promise<StoredSessionRow[]> | StoredSessionRow[];
 
+  getSingleCoValueSession(
+    coValueRowId: number,
+    sessionID: SessionID,
+  ): Promise<StoredSessionRow | undefined> | StoredSessionRow | undefined;
+
   getNewTransactionInSession(
     sessionRowId: number,
     firstNewTxIdx: number,
@@ -79,5 +84,5 @@ export interface DBClientInterface {
     signature: Signature;
   }): Promise<number> | void | unknown;
 
-  unitOfWork(operationsCallback: () => unknown[]): Promise<unknown> | void;
+  transaction(callback: () => unknown): Promise<unknown> | void;
 }

tests/e2e/src/app.tsx

@@ -2,6 +2,7 @@ import React from "react";
 import ReactDOM from "react-dom/client";
 import { Link, RouterProvider, createBrowserRouter } from "react-router-dom";
 import { AuthAndJazz } from "./jazz";
+import { ConcurrentChanges } from "./pages/ConcurrentChanges";
 import { FileStreamTest } from "./pages/FileStream";
 import { InboxPage } from "./pages/Inbox";
 import { ResumeSyncState } from "./pages/ResumeSyncState";
@@ -31,6 +32,9 @@ function Index() {
       <li>
         <Link to="/write-only">Write Only</Link>
       </li>
+      <li>
+        <Link to="/concurrent-changes">Concurrent Changes</Link>
+      </li>
       <li>
         <Link to="/inbox">Inbox</Link>
       </li>
@@ -67,6 +71,10 @@ const router = createBrowserRouter([
     path: "/inbox",
     element: <InboxPage />,
   },
+  {
+    path: "/concurrent-changes",
+    element: <ConcurrentChanges />,
+  },
   {
     path: "/",
     element: <Index />,

tests/e2e/src/pages/ConcurrentChanges.tsx

@@ -0,0 +1,75 @@
+import { useAccount, useCoState } from "jazz-react";
+import { CoFeed, Group, ID, co } from "jazz-tools";
+import { useEffect, useState } from "react";
+
+export class Counter extends CoFeed.Of(co.json<{ value: number }>()) {}
+
+function getIdParam() {
+  const url = new URL(window.location.href);
+  return (url.searchParams.get("id") as ID<Counter>) ?? undefined;
+}
+
+export function ConcurrentChanges() {
+  const [id, setId] = useState(getIdParam);
+  const counter = useCoState(Counter, id, []);
+  const { me } = useAccount();
+
+  useEffect(() => {
+    if (id) {
+      const url = new URL(window.location.href);
+      url.searchParams.set("id", id);
+      history.pushState({}, "", url.toString());
+    }
+  }, [id]);
+
+  useEffect(() => {
+    if (counter?.byMe) {
+      count(counter);
+    }
+  }, [counter?.byMe?.value !== undefined]);
+
+  const createCounter = () => {
+    if (!me) return;
+
+    const group = Group.create();
+
+    group.addMember("everyone", "writer");
+
+    const id = Counter.create([{ value: 0 }], group).id;
+
+    setId(id);
+
+    window.open(`?id=${id}`, "_blank");
+  };
+
+  const done = Object.entries(counter?.perSession ?? {}).every(
+    ([_, entry]) => entry.value.value === 300,
+  );
+
+  return (
+    <div>
+      <h1>Concurrent Changes</h1>
+      <p>
+        {Object.entries(counter?.perSession ?? {}).map(([sessionId, entry]) => (
+          <div key={sessionId}>
+            <p>{sessionId}</p>
+            <p data-testid="value">{entry.value.value}</p>
+          </div>
+        ))}
+      </p>
+      <button onClick={createCounter}>Create a new value!</button>
+      {done && <p data-testid="done">Done!</p>}
+    </div>
+  );
+}
+
+async function count(counter: Counter) {
+  if (!counter.byMe) return;
+
+  let value = counter.byMe.value?.value ?? 0;
+
+  while (value < 300) {
+    await new Promise((resolve) => setTimeout(resolve, 10));
+    counter.push({ value: ++value });
+  }
+}

tests/e2e/tests/ConcurrentChanges.test.ts

@@ -0,0 +1,35 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("Concurrent Changes", () => {
+  test("should complete the task without incurring on InvalidSignature errors", async ({
+    page,
+    context,
+  }) => {
+    await page.goto("/concurrent-changes");
+    const newPage = await context.newPage();
+
+    await page.getByRole("button", { name: "Create a new value!" }).click();
+
+    await newPage.goto(page.url());
+
+    await page.getByTestId("done").waitFor();
+
+    await newPage.close();
+
+    const errorLogs: string[] = [];
+
+    page.on("console", (message) => {
+      if (message.type() === "error") {
+        errorLogs.push(message.text());
+      }
+    });
+
+    await page.reload();
+
+    await expect(page.getByTestId("done")).toBeVisible();
+
+    expect(
+      errorLogs.find((log) => log.includes("InvalidSignature")),
+    ).toBeUndefined();
+  });
+});