Error when using js-yaml together with js-yaml-js-types

[SolomoN-ua]

Hi guys,

After update to latest js-yaml version (4.1.0) inside of our project load-grunt-config some of our users started receiving following error:

>> YAMLException: Schema.extend argument should be a Type, [ Type ], or a schema definition ({ implicit: [...], explicit: [...] })
Warning: Task "default" not found. Use --force to continue.

code that we are using is quite simple:

var yaml = require('js-yaml');
var schema = yaml.DEFAULT_SCHEMA.extend(require('js-yaml-js-types').regexp);

you can find it here

After some investigation looks like the issue is with the following check

if (definition instanceof Type) {

Looks like the possible reason is multiple versions of js-yarn (including old 3.x.x) inside the node_modules, because of different other dependencies. Maybe it could be fixed by adding js-yarn as non-dev dependency inside of js-yaml-js-types, but that is just an idea. Or maybe the check itself should be improved somehow.

Could you please help us to resolve this issue?

Some other details:
js-yaml: 4.1.0
js-yaml-js-types: 1.0.0
link to the original issue: firstandthird/load-grunt-config#194

[puzrin]

IMO npm's dependency graph is a bit out of scope. You could delete deps, lockfile and install deps from scratch.

If you try to report a bug - then create a minimalistic example, confirming unexpected behavior (without extra dependencies).