rename dv to dataValidation for readability

objects/Entity.mjs

@@ -1,4 +1,4 @@
-import dv from "./dv.mjs"
+import dv from "./dataValidation.mjs"
 export default class Entity{
     set _id(prop){
         if(prop){

objects/Publication.mjs

@@ -1,9 +1,9 @@
 import Title from "./Title.mjs";
-import dv from "./dv.mjs";
+import dataValidation from "./dataValidation.mjs";
 export default class Publication extends Title{
     set _link(prop){
         if(prop){
-            if(!dv.isString(prop)){throw new TypeError("link must be a string")}
+            if(!dataValidation.isString(prop)){throw new TypeError("link must be a string")}
             this.link=prop
         }
     }

objects/Title.mjs

@@ -1,16 +1,16 @@
 import Entity from "./Entity.mjs";
-import dv from "./dv.mjs";
+import dataValidation from "./dataValidation.mjs";
 //THIS CLASS WILL HANDLE JUNCTION TABLE STUFF
 export default class Title extends Entity{
     set _title(prop){
         if(prop){
-            if(!dv.isString(prop)){throw new TypeError("title must be a string")}
+            if(!dataValidation.isString(prop)){throw new TypeError("title must be a string")}
             this.title=prop
         }
     }
     set _genres(prop){
         if(prop){
-            if(!dv.isObject(prop)){throw new TypeError("genres must be an object")}
+            if(!dataValidation.isObject(prop)){throw new TypeError("genres must be an object")}
             this.genres=prop
         }
     }

objects/dataValidation.mjs

@@ -0,0 +1,23 @@
+import { DateTime } from "luxon"
+
+export default {
+    isNumber (n){
+        if(isNaN(n)){return false}
+        if (typeof n === "number") { return true }
+        return false
+    },
+    isString (s){
+        if (typeof s === 'string') { return true }
+        return false
+    },
+    dateStringIsValid(str){
+        if(str===null){return true}
+        if(DateTime.fromFormat(str,'yyyy-MM-dd').isValid){
+            return true
+        }
+        return false
+    },
+    isObject(objValue) {
+        return objValue && typeof objValue === 'object' && objValue.constructor === Object;
+      }
+}