Keep fileName property of diagnostic objects and related information

[spahnke]

Using the code below in the Monaco playground I was wondering why the related information shows the wrong file. The diagnostic references the current editor model instead of the file where the class has already been declared.

This is caused by this helper function that clears the entire file object in order to avoid cyclic references during JSON serialization:

monaco-typescript/src/tsWorker.ts

Lines 180 to 191 in e8b0174

	private static clearFiles(diagnostics: ts.Diagnostic[]): Diagnostic[] {
	// Clear the `file` field, which cannot be JSON'yfied because it
	// contains cyclic data structures.
	diagnostics.forEach((diag) => {
	diag.file = undefined;
	const related = <ts.Diagnostic[]>diag.relatedInformation;
	if (related) {
	related.forEach((diag2) => (diag2.file = undefined));
	}
	});
	return <Diagnostic[]>diagnostics;
	}

If we instead clear everything of the file object but the fileName property, we get accurate diagnostics:

monaco.languages.typescript.javascriptDefaults.setDiagnosticsOptions({
	noSemanticValidation: false,
	noSyntaxValidation: false
});

monaco.languages.typescript.javascriptDefaults.setCompilerOptions({
	target: monaco.languages.typescript.ScriptTarget.ES6,
	allowNonTsExtensions: true
});

// extra libraries
var libSource = [
	'declare class Facts {',
	'    /**',
	'     * Returns the next fact',
	'     */',
	'    static next():string',
	'}',
].join('\n');
var libUri = 'ts:filename/facts.d.ts';
monaco.languages.typescript.javascriptDefaults.addExtraLib(libSource, libUri);
// When resolving definitions and references, the editor will try to use created models.
// Creating a model for the library allows "peek definition/references" commands to work with the library.
monaco.editor.createModel(libSource, 'typescript', monaco.Uri.parse(libUri));

monaco.editor.create(document.getElementById('container'), {
	value: 'class Facts {}',
	language: 'javascript'
});

[alexdima]

👍 Thank you!

[oldrich-svec]

I believe this change might have caused this bug:

microsoft/monaco-editor#2392

What I could understand is that the code tries to access "text" property on a diagnostic object but since there is only "fileName" and no "text" property, it crashes.

[spahnke]

Thank you for the issue report! I opened #76 which should fix this.