Computed is not firing

For given code when onFieldChange is called, the computed property named editedFields is not updating. Any help will be appreciated.

class FormsBaseStore {
	constructor() {
		this.form = {};
	}

	//Filters the form fields that were edited
	 @ computed get editedFields() {
		let arrEdited = [];

		const fields = this.form.fields;

		for (var field in fields) {
			(fields[field].isEdited)
			 ? arrEdited.push(fields[field])
			 : null;
		}

		return arrEdited;
	}

	//Use it to instantiate values to the form
	 @ action setFormData(fieldsObj) {

		const {
			id,
			...fields
		} = fieldsObj;

		let newFieldsObj = {};

		for (var field in fields) {
			const newObjValue = (fields[field].value !== null && fields[field].value !== undefined) ? fields[field].value : "";
			const newObjRule = (fields[field].rule) ? fields[field].rule : null;
			(newObjValue !== undefined && newObjValue !== null && newObjValue !== "")
			 ? newFieldsObj[field] = new FormField(field, newObjValue, )
				 : newFieldsObj[field] = new FormField(field, newObjValue);
		}

		this.form = new Form(newFieldsObj, id);

	}

	//this method is called on the onChange event of the form elements
	 @ action.bound onFieldChange(field, value) {

		var fieldName = (typeof(field) === "string") ? field : field.target.name;
		const form = this.form;
		const formField = form.fields[fieldName];

		//Setting item value
		(value == undefined || value == null) ? value = "" : null;
		let fieldValue = (value !== undefined && value !== "") ? value : (typeof(field) === "string") ? "" : field.target.value;
		(fieldValue == undefined || fieldValue == null) ? fieldValue = "" : fieldValue;

		formField.value = fieldValue;

		//controlling edition
		this.checkIfEdited(formField);

	}

	checkIfEdited = (field) => {
		let value = field.value;
		let defaultValue = field.defaultValue;

		if (isObservable(field.defaultValue)) {
			defaultValue = toJS(field.defaultValue);
			value = toJS(field.value);
		}

		if (defaultValue !== value && !Array.isArray(defaultValue) && typeof defaultValue !== 'object') {
			field.isEdited = true;
		} else if ((Array.isArray(defaultValue) || typeof defaultValue === 'object') && !isEqual(defaultValue, value)) {
			field.isEdited = true;
		} else if (!field.isValid) {
			field.isEdited = true;
		} else {
			field.isEdited = false;
			field.container = null;
		}
	}

}

class Form {
	constructor(fields, id) {
		this.fields = fields;
		this.meta.id = id;
	}

	 @ observable fields = {};
	 @ observable meta = {
		id: null
	}
}

class FormField {
	 @ observable name;
	 @ observable value;
	 @ observable isEdited;

	constructor(name = null, value = "", isEdited = false) {

		this.name = name;
		this.value = value;
		this.isEdited = isEdited;
	}

}

[ItamarShDev]

@gs-trader if this matter is solved for you, please consider closing the issue

[mweststrate]

@gs-trader yes, form must be declared as observable, otherwise mobx cannot track reassignments to that property! And you are reassinging it in setFormData: this.form = new Form(newFieldsObj, id);

A rule of thumb you can use: either all fields should be readonly or @observable. If it is neither, than you have something for which no changes can be tracked. Marking that field as readonly would have resulted in a compile error in typescript in the setFormData method.