Added StringUtils#join

Author: wintondeshong

src/utilities/string-utils.test.ts

@@ -114,6 +114,55 @@ describe("StringUtils", () => {
 
     // #endregion isValidEmail
 
+    // -----------------------------------------------------------------------------------------
+    // #region join()
+    // -----------------------------------------------------------------------------------------
+
+    describe("join()", () => {
+        describe("with the default separator", () => {
+            type JoinTestTypes = [string[], string];
+
+            test.each<JoinTestTypes>([
+                [[], ""],
+                [["a"], "a"],
+                [["a"], "a"],
+                [["a", "b"], "a,b"],
+            ])(
+                "when values is %p,  returns %p",
+                (values: string[], expected: string) => {
+                    // Arrange & Act
+                    const result: string = StringUtils.join(values);
+
+                    // Assert
+                    expect(result).toBe(expected);
+                }
+            );
+        });
+
+        describe("with a separator argument", () => {
+            type JoinTestTypesWithSeparator = [string[], string, string];
+
+            test.each<JoinTestTypesWithSeparator>([
+                [[], "", ""],
+                [["a"], "", "a"],
+                [["a"], ",", "a"],
+                [["a", "b"], "", "ab"],
+                [["a", "b"], " ", "a b"],
+            ])(
+                "when values is %p and separator is %p, returns %p",
+                (values: string[], separator: string, expected: string) => {
+                    // Arrange & Act
+                    const result: string = StringUtils.join(values, separator);
+
+                    // Assert
+                    expect(result).toBe(expected);
+                }
+            );
+        });
+    });
+
+    // #endregion join
+
     // -----------------------------------------------------------------------------------------
     // #region truncateRight()
     // -----------------------------------------------------------------------------------------

src/utilities/string-utils.ts

@@ -1,3 +1,4 @@
+import { CollectionUtils } from "./collection-utils";
 import _ from "lodash";
 
 // -----------------------------------------------------------------------------------------
@@ -48,6 +49,22 @@ const isEmpty = (value?: string): boolean =>
 const isValidEmail = (value?: string): boolean =>
     value != null && REGEX_VALID_EMAIL.test(value);
 
+/**
+ * Joins an array of strings into one string with a separator. If the array is empty, it will return an empty string.
+ *
+ * @default ""
+ * @param {string[]} values Values to join into one string.
+ * @param {string} [separator=","] String to seperate each of the given values.
+ * @returns {string}
+ */
+const join = (values: string[], separator: string = ","): string => {
+    if (CollectionUtils.isEmpty(values)) {
+        return "";
+    }
+
+    return values.join(separator);
+};
+
 const truncateRight = (value: string, truncateAtPos: number): string => {
     if (value.length <= truncateAtPos) {
         return value;
@@ -73,6 +90,7 @@ export const StringUtils = {
     hasValue,
     isEmpty,
     isValidEmail,
+    join,
     lowerFirst: _.lowerFirst,
     pad: _.pad,
     padEnd: _.padEnd,