feat(string): adds support for generating ULID

src/modules/string/index.ts

@@ -704,6 +704,59 @@ export class StringModule extends SimpleModuleBase {
       .replaceAll('y', () => this.faker.number.hex({ min: 0x8, max: 0xb }));
   }
 
+  /**
+   * Returns a ULID ([Universally Unique Lexicographically Sortable Identifier](https://github.com/ulid/spec)).
+   *
+   * @param options The optional options object.
+   * @param options.refDate The date to use as reference point for the newly generated ULID encoded timestamp. Defaults to `faker.defaultRefDate()`.
+   *
+   * @example
+   * faker.string.ulid() // '01ARZ3NDEKTSV4RRFFQ69G5FAV'
+   *
+   * @since 8.2.0
+   */
+  ulid(
+    options: {
+      /**
+       * The date to use as reference point for the newly generated ULID encoded timestamp.
+       *
+       * @default faker.defaultRefDate()
+       */
+      refDate?: string | Date | number;
+    } = {}
+  ): string {
+    const encodingCharacters = '0123456789ABCDEFGHJKMNPQRSTVWXYZ'; // Crockford's Base32 - Excludes I, L, O, and U which may be confused with numbers
+    const encodingLength = encodingCharacters.length;
+    const encodeTime = (now: number) => {
+      let mod;
+      let len = 10;
+      let str = '';
+      for (; len > 0; len--) {
+        mod = now % encodingLength;
+        str = encodingCharacters.charAt(mod) + str;
+        now = (now - mod) / encodingLength;
+      }
+
+      return str;
+    };
+
+    const { refDate } = options;
+    let date = refDate;
+
+    if (date == null) {
+      date = this.faker.defaultRefDate();
+    }
+
+    date = new Date(date);
+    if (Number.isNaN(date.valueOf())) {
+      date = this.faker.defaultRefDate();
+    }
+
+    return (
+      encodeTime(date.getTime()) + this.fromCharacters(encodingCharacters, 16)
+    );
+  }
+
   /**
    * Generates a [Nano ID](https://github.com/ai/nanoid).
    *

test/modules/__snapshots__/string.spec.ts.snap

@@ -1,4 +1,4 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
 exports[`string > 42 > alpha > noArgs 1`] = `"t"`;
 
@@ -164,6 +164,22 @@
 
 exports[`string > 42 > symbol > with length range 1`] = `"}\\>%%"\`>[!~_'&"`;
 
+exports[`string > 42 > ulid > noArgs 1`] = `"01HSCFQK6RBYQK441VKP0ZT655"`;
+
+exports[`string > 42 > ulid > noArgs 2`] = `"01HSCFQK6R9GD9K49BES6GJ1K5"`;
+
+exports[`string > 42 > ulid > noArgs 3`] = `"01HSCFQK6S2YYS93NE3F1X8N9G"`;
+
+exports[`string > 42 > ulid > noArgs 4`] = `"01HSCFQK6SH5ZRYWKX261AC8TB"`;
+
+exports[`string > 42 > ulid > noArgs 5`] = `"01HSCFQK6S8H4S2ZR60TPQR2B3"`;
+
+exports[`string > 42 > ulid > with only Date refDate 1`] = `"01EZ2S259ZBYQK441VKP0ZT655"`;
+
+exports[`string > 42 > ulid > with only number refDate 1`] = `"01EZ2S259ZBYQK441VKP0ZT655"`;
+
+exports[`string > 42 > ulid > with only string refDate 1`] = `"01EZ2S259ZBYQK441VKP0ZT655"`;
+
 exports[`string > 42 > uuid 1`] = `"5fb9220d-9b0f-4d32-a248-6492457c3890"`;
 
 exports[`string > 42 > uuid 2`] = `"21ffc41a-7170-4e4a-9488-2fcfe9e13056"`;
@@ -338,6 +354,22 @@
 
 exports[`string > 1211 > symbol > with length range 1`] = `"{(~@@],[_]?_.\`\`'=',~"`;
 
+exports[`string > 1211 > ulid > noArgs 1`] = `"01HSCFQK7SXW7ZNNRBPTRMTDVV"`;
+
+exports[`string > 1211 > ulid > noArgs 2`] = `"01HSCFQK7S6J6BZRCXHZ79PGBV"`;
+
+exports[`string > 1211 > ulid > noArgs 3`] = `"01HSCFQK7SC895HP4PF7D6VJF1"`;
+
+exports[`string > 1211 > ulid > noArgs 4`] = `"01HSCFQK7SP5P8RGE6KV3VECFJ"`;
+
+exports[`string > 1211 > ulid > noArgs 5`] = `"01HSCFQK7SSHXZTV7PTAW0HRE2"`;
+
+exports[`string > 1211 > ulid > with only Date refDate 1`] = `"01EZ2S259ZXW7ZNNRBPTRMTDVV"`;
+
+exports[`string > 1211 > ulid > with only number refDate 1`] = `"01EZ2S259ZXW7ZNNRBPTRMTDVV"`;
+
+exports[`string > 1211 > ulid > with only string refDate 1`] = `"01EZ2S259ZXW7ZNNRBPTRMTDVV"`;
+
 exports[`string > 1211 > uuid 1`] = `"ee3faac5-bdca-4d6d-9d39-35fc6e8f34b8"`;
 
 exports[`string > 1211 > uuid 2`] = `"d64428b2-b736-43d9-970b-2b4c8739d1d7"`;
@@ -512,6 +544,22 @@
 
 exports[`string > 1337 > symbol > with length range 1`] = `"&)/+;)~\\$-?%"`;
 
+exports[`string > 1337 > ulid > noArgs 1`] = `"01HSCFQK89858EAG8ZQ3CM4ZES"`;
+
+exports[`string > 1337 > ulid > noArgs 2`] = `"01HSCFQK89SBDJR69NF5D6HT5Y"`;
+
+exports[`string > 1337 > ulid > noArgs 3`] = `"01HSCFQK89DGG0QZ54BP0B1SBP"`;
+
+exports[`string > 1337 > ulid > noArgs 4`] = `"01HSCFQK89FZTKJZ802YZFAQ0R"`;
+
+exports[`string > 1337 > ulid > noArgs 5`] = `"01HSCFQK89N6NX5XAP8G5EECSF"`;
+
+exports[`string > 1337 > ulid > with only Date refDate 1`] = `"01EZ2S259Z858EAG8ZQ3CM4ZES"`;
+
+exports[`string > 1337 > ulid > with only number refDate 1`] = `"01EZ2S259Z858EAG8ZQ3CM4ZES"`;
+
+exports[`string > 1337 > ulid > with only string refDate 1`] = `"01EZ2S259Z858EAG8ZQ3CM4ZES"`;
+
 exports[`string > 1337 > uuid 1`] = `"4247584f-b16a-42f7-8cc5-69c34a72638d"`;
 
 exports[`string > 1337 > uuid 2`] = `"f6880bf2-25b0-450c-a5b7-fd99f401ff75"`;

test/modules/string.spec.ts

@@ -113,6 +113,17 @@ describe('string', () => {
 
     t.itRepeated('uuid', 5);
 
+    t.describe('ulid', (t) => {
+      const ulidRefDate = '2021-02-21T17:09:15.711Z';
+
+      t.itRepeated('noArgs', 5)
+        .it('with only string refDate', { refDate: ulidRefDate })
+        .it('with only Date refDate', { refDate: new Date(ulidRefDate) })
+        .it('with only number refDate', {
+          refDate: new Date(ulidRefDate).getTime(),
+        });
+    });
+
     t.describe('nanoid', (t) => {
       t.itRepeated('noArgs', 5)
         .it('with length parameter', 30)
@@ -750,6 +761,14 @@ describe('string', () => {
         });
       });
 
+      describe(`ulid`, () => {
+        it('generates a valid ULID', () => {
+          const ulid = faker.string.ulid();
+          const regex = /^[0-7][0-9A-HJKMNP-TV-Z]{25}$/;
+          expect(ulid).toMatch(regex);
+        });
+      });
+
       describe(`nanoid`, () => {
         it('generates a valid Nano ID', () => {
           const id = faker.string.nanoid();