extensions/typescript-language-features/src/tsServer/bufferSyncSupport.ts/BufferSyncSupport/shouldValidate
class BufferSyncSupport:	private shouldValidate(buffer: SyncedBuffer): boolean {
		if (!this.client.configuration.enableProjectDiagnostics && !this._tabResources.has(buffer.resource)) { // Only validate resources that are showing to the user
			return false;
		}

		switch (buffer.kind) {
			case BufferKind.JavaScript:
				return this._validateJavaScript;

			case BufferKind.TypeScript:
			default:
				return this._validateTypeScript;
		}
	}