Added ScrollUtils as well as CollectionUtils methods

Author: wintondeshong

src/index.ts

@@ -38,6 +38,7 @@ export { KeyValuePair } from "./interfaces/key-value-pair";
 export { PagedResult } from "./interfaces/paged-result";
 export { Result } from "./interfaces/result";
 export { ResultError } from "./interfaces/result-error";
+export { ScrollOptions } from "./interfaces/scroll-options";
 export { ServiceResponse } from "./interfaces/service-response";
 
 // #endregion Interfaces
@@ -60,6 +61,7 @@ export { EnvironmentUtils } from "./utilities/environment-utils";
 export { LocalizationUtils } from "./utilities/localization-utils";
 export { PromiseFactory } from "./utilities/promise-factory";
 export { RouteUtils } from "./utilities/route-utils";
+export { ScrollUtils } from "./utilities/scroll-utils";
 export { ServiceUtils } from "./utilities/service-utils";
 export { StringUtils } from "./utilities/string-utils";
 

src/interfaces/scroll-options.ts

@@ -0,0 +1,3 @@
+export interface ScrollOptions extends ScrollIntoViewOptions {
+    initialDelay?: number;
+}

src/utilities/collection-utils.test.ts

@@ -386,6 +386,45 @@ describe("CollectionUtils", () => {
         });
     });
 
+    describe("#removeElementAt", () => {
+        it("When index i < 0, returns source array", () => {
+            // Arrange
+            const arr = ["one", "two", "three"];
+            const expected = [...arr];
+
+            // Act
+            const result = CollectionUtils.removeElementAt(arr, -1);
+
+            // Assert
+            expect(result).toStrictEqual(expected);
+        });
+
+        it("When index > array.length, returns source array", () => {
+            // Arrange
+            const arr = ["one", "two", "three"];
+            const expected = [...arr];
+
+            // Act
+            const result = CollectionUtils.removeElementAt(arr, 50);
+
+            // Assert
+            expect(result).toStrictEqual(expected);
+        });
+
+        it("When index is in range, then removes element at index", () => {
+            // Arrange
+            const arr = ["one", "two", "three"];
+            const expected = ["one", "three"];
+            const indexToRemove = 1;
+
+            // Act
+            const result = CollectionUtils.removeElementAt(arr, indexToRemove);
+
+            // Assert
+            expect(result).toStrictEqual(expected);
+        });
+    });
+
     describe("#replaceElementAt", () => {
         it("Replaces element at specified index and returns a new array", () => {
             // Arrange

src/utilities/collection-utils.ts

@@ -138,6 +138,21 @@ const _length = (arr: Array<any> | List<any>): number => {
     return (arr as Array<any>).length;
 };
 
+/**
+ * Removes a supplied element by index
+ * @param source original array
+ * @param index array index to remove
+ */
+const _removeElementAt = <T>(source: Array<T>, index: number): Array<T> => {
+    if (index < 0 || index > source.length) {
+        return source;
+    }
+
+    const newArr = [...source];
+    newArr.splice(index, 1);
+    return newArr;
+};
+
 /**
  * Returns a NEW array with the element at the specified index
  * replaced with the specified value. Since it returns a new array,
@@ -181,6 +196,7 @@ export const CollectionUtils = {
     isEmpty: _isEmpty,
     isNotEmpty: _isNotEmpty,
     length: _length,
+    removeElementAt: _removeElementAt,
     replaceElementAt: _replaceElementAt,
     sample: _.sample,
     sampleSize: _.sampleSize,

src/utilities/scroll-utils.test.ts

@@ -0,0 +1,3 @@
+describe("ScrollUtils", () => {
+    test.skip("TOOD: Backfill tests for issue https://github.com/AndcultureCode/AndcultureCode.JavaScript.Core/issues/26", () => {});
+});

src/utilities/scroll-utils.ts

@@ -0,0 +1,95 @@
+import { EnvironmentUtils } from "./environment-utils";
+import { ScrollOptions } from "../interfaces/scroll-options";
+import { StringUtils } from "./string-utils";
+
+// -----------------------------------------------------------------------------------------
+// #region Constants
+// -----------------------------------------------------------------------------------------
+
+export const DefaultScrollOptions: ScrollOptions = {
+    behavior: "auto",
+    block: "start",
+    inline: "nearest",
+};
+
+// #endregion Constants
+
+// -----------------------------------------------------------------------------------------
+// #region Functions
+// -----------------------------------------------------------------------------------------
+
+/**
+ * Attempts to scroll to the element specified by the given ID.
+ * In the event of a slow page render, the element may not be immediately available.
+ * This method will retry up to 50 times every 100ms to find the element before
+ * giving up.
+ */
+const _scrollToElementById = (
+    id: string,
+    options: ScrollOptions = DefaultScrollOptions
+) => {
+    let retryCount = 0;
+    const tryToScroll = () => {
+        retryCount += 1;
+
+        if (retryCount > 50) {
+            EnvironmentUtils.runIfDevelopment(() =>
+                console.warn(
+                    `Could not find element with ID ${id} in the page.`
+                )
+            );
+
+            // couldn't find element in 50 loops, give up.
+            return;
+        }
+
+        const el = document.getElementById(id);
+        if (el != null) {
+            el.scrollIntoView(options);
+            return;
+        }
+
+        setTimeout(tryToScroll, 100);
+    };
+
+    if (options.initialDelay != null) {
+        setTimeout(tryToScroll, options.initialDelay);
+        return;
+    }
+
+    tryToScroll();
+};
+
+/**
+ * Attempts to scroll to the element specified in the hash of the current path.
+ * In the event of a slow page render, the element may not be immediately available.
+ * This method will retry up to 50 times every 100ms to find the element before
+ * giving up.
+ *
+ * Reference:
+ * https://stackoverflow.com/a/54042987
+ * https://stackoverflow.com/a/48195222
+ */
+const _scrollToHash = (
+    location: any,
+    options: ScrollOptions = DefaultScrollOptions
+) => {
+    if (StringUtils.isEmpty(location.hash)) {
+        return;
+    }
+
+    const id = location.hash.replace("#", "");
+    _scrollToElementById(id, options);
+};
+
+// #endregion Functions
+
+// -----------------------------------------------------------------------------------------
+// #region Exports
+// -----------------------------------------------------------------------------------------
+
+export const ScrollUtils = {
+    scrollToHash: _scrollToHash,
+};
+
+// #endregion Exports