Errors

Use this page to look up an error code and fix what caused it. Every package uses the same codes, so you can handle errors the same way in Rust, TypeScript, and Dart.

Reading the code

Language	Error type	Code
TypeScript	`CanvistError`	`error.code`, after `isCanvistError(error)`
Rust	`HeadlessError`	`error.code()`, an `ErrorCode`
Dart	`CanvistException`	`exception.code`, an `ErrorCode`

import { createEngine, isCanvistError } from "@canvist/headless";

const engine = await createEngine();
const stored = '{ "type": "doc", "content": [{ "type": "image" }] }';
try {
	engine.fromJson(JSON.parse(stored));
} catch (error) {
	if (!isCanvistError(error)) throw error;
	console.log(error.code);
	// schema
}

Codes

Code	What happened	Fix
`config`	The engine’s extensions don’t fit together	Check the extensions you registered, and the ones they depend on
`parse`	Input isn’t valid in its format, such as malformed JSON	Check the input, or load it as HTML or Markdown, which never fail
`schema`	JSON contains blocks or marks the engine didn’t register	Register the missing extensions, or import through HTML or Markdown
`unknownName`	A command or query name doesn’t exist on this engine	Check the catalogue, and register the extension
`invalidArgs`	A command’s arguments are missing or out of range	Match the command’s arguments, such as a heading level from 1 to 6
`invalidPosition`	A position points at a block that doesn’t exist, or past its text	Use the path of a text block, and an offset in UTF-16 code units within its text
`invalidKey`	A key name passed to `press` isn’t valid	Write keys like `Mod-b` or `Shift-Enter`; see Keyboard shortcuts
`editor`	The editing engine refused a change	Report it, with the document and the call that failed
`snapshot`	A snapshot passed to `restore` is malformed	Pass the string `snapshot()` returned, unchanged
`notShared`	A collaboration call on a document that isn’t shared	Call `share(clientId)` first, or load the document with `fromYjs`
`alreadyShared`	`share` on a document that’s already shared	Share once
`collab`	A Yjs update or sync message couldn’t be decoded or applied	Check the transport passes binary messages through unchanged
`render`	Server-side rendering failed	Check registered fonts are valid TrueType or OpenType files