codex-team/editor.js · error · Error

Index should be greater than or equal to 0

Error message

Index should be greater than or equal to 0

What it means

validateIndex rejects negative indices for blocks.insertMany; an index below 0 is meaningless in the blocks array and throws immediately.

Source

Thrown at src/components/modules/api/blocks.ts:421

    this.Editor.BlockManager.insertMany(blocksToInsert, index);

    // we cast to any because our BlockAPI has no "new" signature
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    return blocksToInsert.map((block) => new (BlockAPI as any)(block));
  };

  /**
   * Validated block index and throws an error if it's invalid
   *
   * @param index - index to validate
   */
  private validateIndex(index: unknown): void {
    if (typeof index !== 'number') {
      throw new Error('Index should be a number');
    }

    if (index < 0) {
      throw new Error(`Index should be greater than or equal to 0`);
    }

    if (index === null) {
      throw new Error(`Index should be greater than or equal to 0`);
    }
  }
}

View on GitHub (pinned to 5f45dabbe5)

Solutions

1. Clamp the index: Math.max(0, index)
2. Fix the off-by-one in the index computation
3. Validate with a guard before calling insertMany

Example fix

// before
editor.blocks.insertMany(newBlocks, currentIndex - 1);
// after
editor.blocks.insertMany(newBlocks, Math.max(0, currentIndex - 1));

index = Math.max(0, index); editor.blocks.insertMany(blocks, index);

const isNonNegativeInt = (i: unknown): i is number => Number.isInteger(i) && (i as number) >= 0;

try { editor.blocks.insertMany(blocks, index); } catch (e) { if (e instanceof Error && e.message.includes('greater than or equal to 0')) { editor.blocks.insertMany(blocks, 0); return; } throw e; }

When it happens

Trigger: Calling insertMany(blocks, -1) or passing a computed index that went negative (e.g. currentIndex - 1 when currentIndex is 0).

Common situations: Off-by-one arithmetic like idx - 1 at the top of the document; clamp logic missing before insertion; parsing '-1' sentinels from external data.

Related errors

• Index should be a number
• Unable to move Block down since it is already the last
• Unable to move Block up since it is already the first
• Incorrect index
• Incorrect data passed to the render() method

AI-assisted analysis of codex-team/editor.js@5f45dabbe5 (2026-08-27). Data as JSON: /api/errors/767d8e97e73c3d7b. Report an issue: GitHub.