Merge pull request #128 from myty/feature/collection-utils-isempty

Typed nullable collection option to isEmpty, hasValues, and isNotEmpty functions

Author: myty

src/utilities/collection-utils.test.ts

@@ -60,20 +60,22 @@ describe("CollectionUtils", () => {
         });
 
         test("given collections is undefined, it returns false", (): void => {
-            // Arrange & Act
-            const result = CollectionUtils.hasValues(
-                (undefined as unknown) as any[]
-            );
+            // Arrange
+            const collection: any[] | undefined = undefined;
+
+            // Act
+            const result = CollectionUtils.hasValues(collection);
 
             // Assert
             expect(result).toBeFalse();
         });
 
         test("given collections is null, it returns false", (): void => {
-            // Arrange & Act
-            const result = CollectionUtils.hasValues(
-                (null as unknown) as any[]
-            );
+            // Arrange
+            const collection: any[] | null = null;
+
+            // Act
+            const result = CollectionUtils.hasValues(collection);
 
             // Assert
             expect(result).toBeFalse();
@@ -140,18 +142,22 @@ describe("CollectionUtils", () => {
         });
 
         test("given collections is undefined, it returns true", (): void => {
-            // Arrange & Act
-            const result = CollectionUtils.isEmpty(
-                (undefined as unknown) as any[]
-            );
+            // Arrange
+            const collection: any[] | undefined = undefined;
+
+            // Act
+            const result = CollectionUtils.isEmpty(collection);
 
             // Assert
             expect(result).toBeTrue();
         });
 
         test("given collections is null, it returns true", (): void => {
-            // Arrange & Act
-            const result = CollectionUtils.isEmpty((null as unknown) as any[]);
+            // Arrange
+            const collection: any[] | null = null;
+
+            // Act
+            const result = CollectionUtils.isEmpty(collection);
 
             // Assert
             expect(result).toBeTrue();
@@ -210,20 +216,22 @@ describe("CollectionUtils", () => {
         });
 
         test("when collections param is undefined, it returns false", (): void => {
-            // Arrange & Act
-            const result = CollectionUtils.isNotEmpty(
-                (undefined as unknown) as any[]
-            );
+            // Arrange
+            const collection: any[] | undefined = undefined;
+
+            // Act
+            const result = CollectionUtils.isNotEmpty(collection);
 
             // Assert
             expect(result).toBeFalse();
         });
 
         test("when collections param is null, it returns false", (): void => {
-            // Arrange & Act
-            const result = CollectionUtils.isNotEmpty(
-                (null as unknown) as any[]
-            );
+            // Arrange
+            const collection: any[] | null = null;
+
+            // Act
+            const result = CollectionUtils.isNotEmpty(collection);
 
             // Assert
             expect(result).toBeFalse();

src/utilities/collection-utils.ts

@@ -80,12 +80,12 @@ const flattenDeep = <T>(
  *
  * Note: only takes a single collection as parameter to make use of Typescript Type guard ability
  *
- * @param {(any[] | Immutable.List<any> | undefined)} collection
+ * @param {(any[] | Immutable.List<any> | null | undefined)} collection
  * @returns {boolean} False if `collection` is `undefined`, `null`, or has 0 elements.
  * True if collection contains any elements.
  */
 const hasValues = (
-    collection: any[] | Immutable.List<any> | undefined
+    collection: any[] | Immutable.List<any> | null | undefined
 ): collection is any[] | Immutable.List<any> => !isEmpty(collection);
 
 /**
@@ -100,7 +100,7 @@ const hasValues = (
  * @param collection
  */
 const isEmpty = (
-    collection: any[] | Immutable.List<any> | undefined
+    collection: any[] | Immutable.List<any> | null | undefined
 ): collection is undefined => {
     if (collection == null) {
         return true;
@@ -119,12 +119,12 @@ const isEmpty = (
  *
  * Note: only takes a single collection as parameter to make use of Typescript Type guard ability
  *
- * @param {(any[] | Immutable.List<any> | undefined)} collection
+ * @param {(any[] | Immutable.List<any> | null | undefined)} collection
  * @returns {boolean} False if `collection` is `undefined`, `null`, or has 0 elements.
  * True if collection contains any elements.
  */
 const isNotEmpty = (
-    collection: any[] | Immutable.List<any> | undefined
+    collection: any[] | Immutable.List<any> | null | undefined
 ): collection is any[] | Immutable.List<any> => hasValues(collection);
 
 /**