feat: add ability to check if model has been saved (#347)

src/packages/database/constants.js

@@ -1,4 +1,7 @@
 // @flow
+import type { Model } from './index';
+
+export const NEW_RECORDS: WeakSet<Model> = new WeakSet();
 export const UNIQUE_CONSTRAINT = /UNIQUE\sCONSTRAINT/ig;
 
 export const VALID_DRIVERS = [

src/packages/database/model/index.js

@@ -1,6 +1,8 @@
 // @flow
 import { pluralize } from 'inflection';
 
+import { NEW_RECORDS } from '../constants';
+
 import Query from '../query';
 import { sql } from '../../logger';
 import { saveRelationships } from '../relationship';
@@ -138,7 +140,7 @@ class Model {
    */
   static relationshipNames: Array<string>;
 
-  constructor(attrs: {} = {}, initialize: boolean = true) {
+  constructor(attrs: Object = {}, initialize: boolean = true) {
     const { constructor: { attributeNames, relationshipNames } } = this;
 
     Object.defineProperties(this, {
@@ -185,13 +187,23 @@ class Model {
       Object.freeze(this);
     }
 
+    NEW_RECORDS.add(this);
+
     return this;
   }
 
+  get isNew(): boolean {
+    return NEW_RECORDS.has(this);
+  }
+
   get isDirty(): boolean {
     return Boolean(this.dirtyAttributes.size);
   }
 
+  get persisted(): boolean {
+    return !this.isNew && !this.isDirty;
+  }
+
   static get hasOne(): Object {
     return Object.freeze({});
   }
@@ -354,6 +366,7 @@ class Model {
         await query;
       }
 
+      NEW_RECORDS.delete(this);
       this.dirtyAttributes.clear();
 
       if (typeof afterUpdate === 'function') {
@@ -498,6 +511,7 @@ class Model {
       });
 
       Object.freeze(instance);
+      NEW_RECORDS.delete(instance);
 
       if (typeof afterCreate === 'function') {
         await afterCreate(instance);

src/packages/database/query/utils/build-results.js

@@ -1,6 +1,8 @@
 // @flow
 import { camelize, singularize } from 'inflection';
 
+import { NEW_RECORDS } from '../../constants';
+
 import Model from '../../model';
 
 import entries from '../../../../utils/entries';
@@ -124,6 +126,9 @@ export default async function buildResults<T: Model>({
         };
       }, {});
 
-    return Reflect.construct(model, [record]);
+    const instance = Reflect.construct(model, [record]);
+
+    NEW_RECORDS.delete(instance);
+    return instance;
   });
 }