Add isDefined and removeUndefineds

src/utils/index.ts

@@ -7,4 +7,5 @@ export * from './format';
 export * from './gas';
 export * from './network';
 export * from './promises';
+export * from './util';
 export * from './versions';

src/utils/util.ts

@@ -0,0 +1,13 @@
+export const isDefined = <T>(a: T | undefined | null): a is T => {
+  return typeof a !== 'undefined' && a !== null;
+};
+
+export const removeUndefineds = <T>(a: Optional<T>[]): T[] => {
+  const newArray: T[] = [];
+  for (const item of a) {
+    if (isDefined(item)) {
+      newArray.push(item);
+    }
+  }
+  return newArray;
+};