Ameerul /P2PS-1563 Migrate string.js to typescript (binary-com#10053)

* chore: migrated string.js to typescript, added test case

* chore: annoted types and replaced deprecated substr with substring

* fix: removed extra nickname check

packages/p2p/src/utils/__tests__/string.spec.ts

@@ -0,0 +1,18 @@
+import { countDecimalPlaces, getShortNickname } from '../string';
+
+describe('countDecimalPlaces', () => {
+    it('should return the correct number of decimal places', () => {
+        expect(countDecimalPlaces(1.234)).toEqual(3);
+        expect(countDecimalPlaces(1.2)).toEqual(1);
+        expect(countDecimalPlaces(1)).toEqual(0);
+    });
+});
+
+describe('getShortNickname', () => {
+    it('should return the correct short nickname', () => {
+        expect(getShortNickname('test')).toEqual('TE');
+        expect(getShortNickname('test123')).toEqual('TE');
+        expect(getShortNickname('test 123')).toEqual('TE');
+        expect(getShortNickname('test 123 .,:;()@#+/-')).toEqual('TE');
+    });
+});

packages/p2p/src/utils/string.ts

@@ -0,0 +1,54 @@
+/**
+ * A function that counts the number of decimal places in a number.
+ * @param {Number | String} value - The number to count the decimal places of.
+ * @returns {Number} The number of decimal places in the number.
+ */
+export const countDecimalPlaces = (value: number | string): number => (value.toString().split('.')?.[1] ?? '').length;
+
+/**
+ * A function that generates a colour from a nickname.
+ *
+ * @deprecated This will be removed once design has provided the correct colour for the user avatar.
+ * @param {String} nickname - The nickname to generate a colour from.
+ * @returns {String} A colour derived from nickname that is in our colours array.
+ */
+export const generateHexColourFromNickname = (nickname: string): string => {
+    if (!nickname) {
+        return '??';
+    }
+
+    const colours = [
+        '#fc4400',
+        '#ff8c00',
+        '#092694',
+        '#527bb5',
+        '#3f6fe5',
+        '#6b4bb6',
+        '#db69e1',
+        '#ca0051',
+        '#3f6fe5',
+        '#f43f83',
+        '#6aba8d',
+        '#3fdce5',
+        '#1fb8bf',
+        '#9ed178',
+        '#71bd0e',
+        '#ff6444',
+    ];
+
+    const colour_hash = nickname.split().reduce((hash, char, idx) => {
+        // Below we get a random colour from the string which is explained here: https://gist.github.com/0x263b/2bdd90886c2036a1ad5bcf06d6e6fb37
+        const char_hash = nickname.charCodeAt(idx) + ((hash << 5) - hash); // eslint-disable-line no-bitwise
+        return char_hash & char_hash; // eslint-disable-line no-bitwise
+    }, 0);
+
+    return colours[((colour_hash % colours.length) + colours.length) % colours.length];
+};
+
+/**
+ * A function that gets the short nickname from a nickname.
+ *
+ * @param {String} nickname - The nickname to get the short nickname from.
+ * @returns {String} The short nickname.
+ */
+export const getShortNickname = (nickname: string): string => nickname?.substring(0, 2).toUpperCase();