Moved helper methods outside of Product and into generic Base class

src/db/models.ts

@@ -2,21 +2,9 @@
 import { arrayProp, prop, getModelForClass } from '@typegoose/typegoose';
 
 /**
- * @class A interface for the Product schema. The model is derived from the properties and their decorators.
- * The class also has a lot of static methods to validate itself and its properties.
+ * @class Base class for models with helper functions to validate JSON inputs
  */
-export class Product {
-    @prop({ required: true, unique: true, dropDupes: true })
-    public identifier!: string;
-    @prop({ required: true })
-    public name!: string;
-    @prop({ required: true })
-    public price!: number;
-    @arrayProp({ items: String })
-    public sizes?: string[];
-    @prop({ required: true })
-    public category!: string;
-
+class BaseModel {
     /**
      * Validates sizes array, making sure it either is undefined, or defined. All items have to be strings.
      * @param possibleArray - Object to run tests against. Can be anything.
@@ -79,12 +67,31 @@ export class Product {
         // For simplicity, we will reject strings that can be converted to numbers for now
         return false;
     }
+}
+
+
+/**
+ * @class A interface for the Product schema. The model is derived from the properties and their decorators.
+ * The class inherits helper methods to validate itself and its properties.
+ */
+export class Product extends BaseModel {
+    @prop({ required: true, unique: true, dropDupes: true })
+    public identifier!: string;
+    @prop({ required: true })
+    public name!: string;
+    @prop({ required: true })
+    public price!: number;
+    @arrayProp({ items: String })
+    public sizes?: string[];
+    @prop({ required: true })
+    public category!: string;
 
     /**
      * Validates object if it can be cast to product interface.
      * Checks if all required fields are provided and that the data meets the guidelines.
      * If extra fields given, we will just ignore them. Possible issue here because we are failing quietly.
      * @param jsonInput - Object to be casted to Product interface
+     * @throws error if a received part of data is not valid and cannot be parsed
      * @returns Product interface with valid fields and data
      */
     public static fromJson(jsonInput: any): Product {

tslint.json

@@ -6,7 +6,8 @@
     "jsRules": {},
     "rules": {        
         "no-console": false,
-        "semicolon": true
+        "semicolon": true,
+        "max-classes-per-file": false
     },
     "rulesDirectory": []
 }