fix: added dependencies for development. feat: added axios as dependency. feat: added some initial modeals. feat: setup unit testing

src/models/ArgumentValidator.ts

@@ -0,0 +1,17 @@
+export class ArgumentValidator {
+    public static isNullOrWhiteSpace(value: string | null | undefined): boolean {
+      return value === null || value === undefined || (/^\s*$/).test(value);
+    }
+
+    public static isValidUrl(value: string | null | undefined): boolean {
+      let url: URL;
+
+      try {
+        url = new URL(value);
+      } catch (error) {
+        return false;
+      }
+
+      return url.protocol === 'http:' || url.protocol === 'https:';
+    }
+}