imp(): implement all operations transformations

packages/collaboration-manager/src/BatchedOperation.spec.ts

@@ -0,0 +1,172 @@
+import type { Index } from '@editorjs/model';
+import { createDataKey, IndexBuilder, type TextRange } from '@editorjs/model';
+import { BatchedOperation } from './BatchedOperation.js';
+import type { SerializedOperation } from './Operation.js';
+import { Operation, OperationType } from './Operation.js';
+
+const createIndexByRange = (range: TextRange): Index => new IndexBuilder()
+  .addBlockIndex(0)
+  .addDataKey(createDataKey('key'))
+  .addTextRange(range)
+  .build();
+
+const templateIndex = createIndexByRange([0, 0]);
+
+const userId = 'user';
+
+describe('BatchedOperation', () => {
+  it('should add Insert operation to batch', () => {
+    const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+    const op2 = new Operation(OperationType.Insert, createIndexByRange([1, 1]), { payload: 'b' }, userId);
+
+    const batch = new BatchedOperation(op1);
+
+    batch.add(op2);
+
+    const operations = batch.operations;
+
+    expect(operations).toEqual([op1, op2]);
+  });
+
+  it('should add Delete operation to batch', () => {
+    const op1 = new Operation(OperationType.Delete, templateIndex, { payload: 'a' }, userId);
+    const op2 = new Operation(OperationType.Delete, createIndexByRange([1, 1]), { payload: 'b' }, userId);
+
+    const batch = new BatchedOperation(op1);
+
+    batch.add(op2);
+
+    const operations = batch.operations;
+
+    expect(operations).toEqual([op1, op2]);
+  });
+
+  describe('from()', () => {
+    it('should create a new batch from an existing batch', () => {
+      const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Insert, createIndexByRange([1, 1]), { payload: 'b' }, userId);
+
+      const originalBatch = new BatchedOperation(op1);
+
+      originalBatch.add(op2);
+
+
+      const newBatch = BatchedOperation.from(originalBatch);
+
+      expect(newBatch.operations).toStrictEqual(originalBatch.operations);
+      expect(newBatch).not.toBe(originalBatch); // Should be a new instance
+    });
+
+    it('should create a new batch from serialized operation', () => {
+      const serializedOp: SerializedOperation<OperationType> = new Operation(OperationType.Delete, templateIndex, { payload: 'a' }, userId).serialize();
+
+      const batch = BatchedOperation.from(serializedOp);
+
+      expect(batch.operations[0].type).toBe(serializedOp.type);
+      expect(batch.operations[0].data).toEqual(serializedOp.data);
+    });
+  });
+
+  describe('inverse()', () => {
+    it('should inverse all operations in the batch', () => {
+      const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Insert, createIndexByRange([1, 1]), { payload: 'b' }, userId);
+
+      const batch = new BatchedOperation(op1);
+
+      batch.add(op2);
+
+      const inversedBatch = batch.inverse();
+
+      expect(inversedBatch.operations[0].type).toBe(OperationType.Delete);
+      expect(inversedBatch.operations[1].type).toBe(OperationType.Delete);
+    });
+  });
+
+  describe('transform()', () => {
+    it('should transform operations against another operation', () => {
+      const op1 = new Operation(OperationType.Insert, createIndexByRange([1, 1]), { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Insert, createIndexByRange([2, 2]), { payload: 'b' }, userId);
+
+      const batch = new BatchedOperation(op1);
+
+      batch.add(op2);
+
+      const againstOp = new Operation(OperationType.Insert, createIndexByRange([0, 0]), { payload: 'x' }, 'other-user');
+
+      const transformedBatch = batch.transform(againstOp);
+
+      expect(transformedBatch).not.toBeNull();
+      expect(transformedBatch!.operations.length).toBe(2);
+      // Check if text ranges were shifted by 1 due to insertion
+      /* eslint-disable @typescript-eslint/no-magic-numbers */
+      expect(transformedBatch!.operations[0].index.textRange![0]).toBe(2);
+      expect(transformedBatch!.operations[1].index.textRange![0]).toBe(3);
+      /* eslint-enable @typescript-eslint/no-magic-numbers */
+    });
+
+    it('should return batch with Neutral operations if no operations can be transformed', () => {
+      const op = new Operation(OperationType.Insert, createIndexByRange([1, 1]), { payload: 'a' }, userId);
+
+      const batch = new BatchedOperation(op);
+
+      const deleteIndex = createIndexByRange([0, 2]);
+
+      // An operation that would make transformation impossible
+      const againstOp = new Operation(OperationType.Delete, deleteIndex, { payload: 'a' }, 'other-user');
+
+      const transformedBatch = batch.transform(againstOp);
+
+      const neutralOp = new Operation(OperationType.Neutral, createIndexByRange([1, 1]), { payload: [] }, userId);
+
+      expect(transformedBatch.operations[0]).toEqual(neutralOp);
+    });
+  });
+
+  describe('canAdd()', () => {
+    it('should return true for consecutive text operations of same type', () => {
+      const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Insert, createIndexByRange([1, 1]), { payload: 'b' }, userId);
+
+      const batch = new BatchedOperation(op1);
+
+      expect(batch.canAdd(op2)).toBe(true);
+    });
+
+    it('should return false for non-consecutive text operations', () => {
+      const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Insert, createIndexByRange([2, 2]), { payload: 'b' }, userId);
+
+      const batch = new BatchedOperation(op1);
+
+      expect(batch.canAdd(op2)).toBe(false);
+    });
+
+    it('should return false for different operation types', () => {
+      const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Delete, createIndexByRange([1, 1]), { payload: 'b' }, userId);
+
+      const batch = new BatchedOperation(op1);
+
+      expect(batch.canAdd(op2)).toBe(false);
+    });
+
+    it('should return false for modify operations', () => {
+      const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Modify, createIndexByRange([1, 1]), { payload: 'b' }, userId);
+
+      const batch = new BatchedOperation(op1);
+
+      expect(batch.canAdd(op2)).toBe(false);
+    });
+
+    it('should return false when payload is a multi-character string', () => {
+      const op1 = new Operation(OperationType.Insert, templateIndex, { payload: 'a' }, userId);
+      const op2 = new Operation(OperationType.Insert, createIndexByRange([1, 1]), { payload: 'bc' }, userId);
+
+      const batch = new BatchedOperation(op1);
+
+      expect(batch.canAdd(op2)).toBe(false);
+    });
+  });
+});

packages/collaboration-manager/src/BatchedOperation.ts

@@ -0,0 +1,155 @@
+import type { InvertedOperationType } from './Operation.js';
+import { Operation, OperationType, type SerializedOperation } from './Operation.js';
+
+/**
+ * Class to batch Text operations (maybe others in the future) for Undo/Redo purposes
+ */
+export class BatchedOperation<T extends OperationType = OperationType> extends Operation<T> {
+  /**
+   * Array of operations to batch
+   */
+  public operations: (Operation<T> | Operation<OperationType.Neutral>)[] = [];
+
+  /**
+   * Batch constructor function
+   *
+   * @param firstOperation - first operation to add
+   */
+  constructor(firstOperation: Operation<T> | Operation<OperationType.Neutral>) {
+    super(firstOperation.type, firstOperation.index, firstOperation.data, firstOperation.userId, firstOperation.rev);
+
+    if (firstOperation !== undefined) {
+      this.add(firstOperation);
+    }
+  }
+
+  /**
+   * Create a new operation batch from an array of operations
+   *
+   * @param opBatch - operation batch to clone
+   */
+  public static from<T extends OperationType>(opBatch: BatchedOperation<T>): BatchedOperation<T>;
+
+  /**
+   * Create a new operation batch from a serialized operation
+   *
+   * @param json - serialized operation
+   */
+  public static from<T extends OperationType>(json: SerializedOperation<T>): BatchedOperation<T>;
+
+  /**
+   * Create a new operation batch from an operation batch or a serialized operation
+   *
+   * @param opBatchOrJSON - operation batch or serialized operation
+   */
+  public static from<T extends OperationType>(opBatchOrJSON: BatchedOperation<T> | SerializedOperation<T>): BatchedOperation<T> {
+    if (opBatchOrJSON instanceof BatchedOperation) {
+      /**
+       * Every batch should have at least one operation
+       */
+      const batch = new BatchedOperation(Operation.from(opBatchOrJSON.operations[0]));
+
+      opBatchOrJSON.operations.slice(1)
+        .forEach((op) => {
+          /**
+           * Deep clone operation to the new batch
+           */
+          batch.add(Operation.from(op));
+        });
+
+      return batch;
+    } else {
+      const batch = new BatchedOperation<T>(Operation.from(opBatchOrJSON));
+
+      return batch;
+    }
+  }
+
+  /**
+   * Adds an operation to the batch
+   * Make sure, that operation could be added to the batch
+   *
+   * @param op - operation to add
+   */
+  public add(op: Operation<T> | Operation<OperationType.Neutral>): void {
+    this.operations.push(op);
+  }
+
+  /**
+   * Method that inverses all of the operations in the batch
+   *
+   * @returns {BatchedOperation<InvertedOperationType<OperationType>>} new batch with inversed operations
+   */
+  public inverse(): BatchedOperation<InvertedOperationType<T>> {
+    const lastOp = this.operations[this.operations.length - 1];
+
+    /**
+     * Every batch should have at least one operation
+     */
+    const newBatchedOperation = new BatchedOperation<InvertedOperationType<T>>(lastOp.inverse());
+
+    this.operations.toReversed().slice(1)
+      .map(op => newBatchedOperation.add(op.inverse()));
+
+    return newBatchedOperation;
+  }
+
+  /**
+   * Method that transforms all of the operations in the batch against another operation
+   *
+   * @param againstOp - operation to transform against
+   * @returns {BatchedOperation} new batch with transformed operations
+   */
+  public transform<K extends OperationType>(againstOp: Operation<K>): BatchedOperation<T | OperationType.Neutral> {
+    const transformedOp = this.operations[0].transform(againstOp);
+
+    const newBatchedOperation = new BatchedOperation(transformedOp);
+
+    this.operations.slice(1).map(op => newBatchedOperation.add(op.transform(againstOp)));
+
+    return newBatchedOperation;
+  }
+
+  /**
+   * Checks if operation can be added to the batch
+   *
+   * Only text operations with the same type (Insert/Delete) on the same block and data key could be added
+   *
+   * @param op - operation to check
+   */
+  public canAdd(op: Operation): boolean {
+    /**
+     * Can't add to batch insertion or deletion of several characters
+     */
+    if (typeof op.data.payload === 'string' && op.data.payload?.length > 1) {
+      return false;
+    }
+
+    const lastOp = this.operations[this.operations.length - 1];
+
+    if (lastOp === undefined) {
+      return true;
+    }
+
+    /**
+     * @todo - implement other index types
+     */
+    if (!op.index.isTextIndex || !lastOp.index.isTextIndex) {
+      return false;
+    }
+
+    if (op.type === OperationType.Modify || lastOp.type === OperationType.Modify) {
+      return false;
+    }
+
+    if (op.type !== lastOp.type) {
+      return false;
+    }
+
+    if (op.index.blockIndex !== lastOp.index.blockIndex || op.index.dataKey !== lastOp.index.dataKey) {
+      return false;
+    }
+
+    return op.index.textRange![0] === lastOp.index.textRange![1] + 1;
+  }
+}