I think you need to open an issue in the Microsoft/monaco-json repository instead.

@rcjsuen that repo doesn't accept issues; it says to file them here.

@TedDriggs Oh, you are right! Don't I feel stupid. Sorry... (><)

@TedDriggs Please describe what you are trying to achieve.

There's monaco.languages.json that let you configure the JSON worker, e.g. if you want validation or not.

To get access to the diagnostic messages, use monaco.editor.getModelMarkers:

You can try this on the Monaco playground:
https://microsoft.github.io/monaco-editor/playground.html#extending-language-services-configure-json-defaults

monaco.languages.json.jsonDefaults.setDiagnosticsOptions({
    validate: true,
    schemas: [{
        uri: "http://myserver/foo-schema.json",
        schema: {
            type: "object",
            properties: {
                q1: {
                    type: "string"
                }
            },
            required: [ 'q1']
        }
    }]
});


var jsonCode = [
    '{',
    '    "$schema": "http://myserver/foo-schema.json"',
    "}"
].join('\n');

monaco.editor.create(document.getElementById("container"), {
    value: jsonCode,
    language: "json"
});

setInterval(() => {
    console.log(monaco.editor.getModelMarkers({}).map(m => m.message).join(', '));
}, 2000);

Check the dev tools console for the output.

@aeschli I'm trying that, but it's always a character behind, and I'm not sure how to mitigate that without adding a timeout and hoping for the best. That's made more complicated because I don't have a good way of checking if the markers are in sync with the model value.

If I could get a Promise or callback when the markers change then I might be able to make this work, but otherwise I'm not able to use the model markers.

Oh, I see. Can you describe what you need the markers for?
A marker change event makes sense. An API on the JSON worker to compute markers would not be hard to add, but it's not something we have at other places.

It's easiest to explain with a picture:

The error that you currently see is a semantic error I've implemented on my own worker thread. I'd like to show schema and syntax errors alongside my semantic errors. Since the other non-Monaco form fields can also have errors, I'm keeping the source-of-truth diagnostics list in the redux store.

(As an aside, I'm planning to figure out the character ranges for those and add my own model markers, but I've run into microsoft/node-jsonc-parser#7 which has stymied that ambition for now.)

Any progress with this? Going through the same goal of trying to validate JSON via the worker vs getModelMarkers.

This provided a workaround #30 (comment)