feat(string): nanoid (#1716)

faker-js · Jan 9, 2023 · 099e76c · 099e76c
1 parent 27dff93
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diff --git a/src/modules/string/index.ts b/src/modules/string/index.ts
@@ -532,6 +532,48 @@ export class StringModule {
     return RFC4122_TEMPLATE.replace(/[xy]/g, replacePlaceholders);
   }
 
+  /**
+   * Generates a [Nano ID](https://github.com/ai/nanoid).
+   *
+   * @param length Length of the generated string. Defaults to `21`.
+   * @param length.min The minimum length of the Nano ID to generate.
+   * @param length.max The maximum length of the Nano ID to generate.
+   *
+   * @example
+   * faker.string.nanoid() // ptL0KpX_yRMI98JFr6B3n
+   * faker.string.nanoid(10) // VsvwSdm_Am
+   * faker.string.nanoid({ min: 13, max: 37 }) // KIRsdEL9jxVgqhBDlm
+   *
+   * @since 8.0.0
+   */
+  nanoid(length: number | { min: number; max: number } = 21): string {
+    length = this.faker.helpers.rangeToNumber(length);
+    if (length <= 0) {
+      return '';
+    }
+
+    const generators = [
+      {
+        value: () => this.alphanumeric(1),
+        // a-z is 26 characters
+        // this times 2 for upper & lower case is 52
+        // add all numbers 0-9 (10 in total) you get 62
+        weight: 62,
+      },
+      {
+        value: () => this.faker.helpers.arrayElement(['_', '-']),
+        weight: 2,
+      },
+    ];
+    let result = '';
+    while (result.length < length) {
+      const charGen = this.faker.helpers.weightedArrayElement(generators);
+      result += charGen();
+    }
+
+    return result;
+  }
+
   /**
    * Returns a string containing only special characters.
    *

diff --git a/test/__snapshots__/string.spec.ts.snap b/test/__snapshots__/string.spec.ts.snap
@@ -78,6 +78,20 @@ exports[`string > 42 > hexadecimal > with length range 1`] = `"0xBE4ABdd39321aD"
 
 exports[`string > 42 > hexadecimal > with length, casing and empty prefix 1`] = `"8be4abd"`;
 
+exports[`string > 42 > nanoid > noArgs 1`] = `"NbMBr6sk8E3-W0ZCB01wo"`;
+
+exports[`string > 42 > nanoid > noArgs 2`] = `"2Ye5CnYsRGr0Wyn0eeGBP"`;
+
+exports[`string > 42 > nanoid > noArgs 3`] = `"aobKqcz1-roVJkzwXQKxA"`;
+
+exports[`string > 42 > nanoid > noArgs 4`] = `"XBhia0_oi0cIMBVEUQr5m"`;
+
+exports[`string > 42 > nanoid > noArgs 5`] = `"FFAhynYQIef2I6rcTtyH8"`;
+
+exports[`string > 42 > nanoid > with length parameter 1`] = `"NbMBr6sk8E3-W0ZCB01wo2Ye5CnYsR"`;
+
+exports[`string > 42 > nanoid > with length range 1`] = `"WJB993RBH1YPdb_iwqiB8i"`;
+
 exports[`string > 42 > numeric > noArgs 1`] = `"3"`;
 
 exports[`string > 42 > numeric > with allowLeadingZeros 1`] = `"4"`;
@@ -226,6 +240,20 @@ exports[`string > 1211 > hexadecimal > with length range 1`] = `"0xaDB42F0e3f4A9
 
 exports[`string > 1211 > hexadecimal > with length, casing and empty prefix 1`] = `"eadb42f"`;
 
+exports[`string > 1211 > nanoid > noArgs 1`] = `"sM8_9dqaK0FJViZZsU9C_"`;
+
+exports[`string > 1211 > nanoid > noArgs 2`] = `"0i1q_zaoUZjAoz4ee2QDc"`;
+
+exports[`string > 1211 > nanoid > noArgs 3`] = `"qApz4EyCu9FHt9xrws3AI"`;
+
+exports[`string > 1211 > nanoid > noArgs 4`] = `"5SxX-57HFuA0KnZgRAyUr"`;
+
+exports[`string > 1211 > nanoid > noArgs 5`] = `"T_mrcROKCRDrUWF5dWr0k"`;
+
+exports[`string > 1211 > nanoid > with length parameter 1`] = `"sM8_9dqaK0FJViZZsU9C_0i1q_zaoU"`;
+
+exports[`string > 1211 > nanoid > with length range 1`] = `"TdZFGLlHOLEPqR-_AcmZLoWxYdiHwl-ngjay"`;
+
 exports[`string > 1211 > numeric > noArgs 1`] = `"9"`;
 
 exports[`string > 1211 > numeric > with allowLeadingZeros 1`] = `"9"`;
@@ -374,6 +402,20 @@ exports[`string > 1337 > hexadecimal > with length range 1`] = `"0xc346ba075bd5"
 
 exports[`string > 1337 > hexadecimal > with length, casing and empty prefix 1`] = `"5c346ba"`;
 
+exports[`string > 1337 > nanoid > noArgs 1`] = `"ydx2eAk_jN5mJ_RM0snwm"`;
+
+exports[`string > 1337 > nanoid > noArgs 2`] = `"tRpr8OTVCXSOGGPC-spDN"`;
+
+exports[`string > 1337 > nanoid > noArgs 3`] = `"GQLX3wG-xgP-RiBh-hv9G"`;
+
+exports[`string > 1337 > nanoid > noArgs 4`] = `"TxLsFyNSRiYIsFStp3G0m"`;
+
+exports[`string > 1337 > nanoid > noArgs 5`] = `"AtcFYs1gw9vinZNdyEHwk"`;
+
+exports[`string > 1337 > nanoid > with length parameter 1`] = `"ydx2eAk_jN5mJ_RM0snwmtRpr8OTVC"`;
+
+exports[`string > 1337 > nanoid > with length range 1`] = `"9hsjwgYJ7nC7YrMNmpA"`;
+
 exports[`string > 1337 > numeric > noArgs 1`] = `"2"`;
 
 exports[`string > 1337 > numeric > with allowLeadingZeros 1`] = `"3"`;

diff --git a/test/string.spec.ts b/test/string.spec.ts
@@ -98,6 +98,12 @@ describe('string', () => {
 
     t.itRepeated('uuid', 5);
 
+    t.describe('nanoid', (t) => {
+      t.itRepeated('noArgs', 5)
+        .it('with length parameter', 30)
+        .it('with length range', { min: 13, max: 37 });
+    });
+
     t.describe('special', (t) => {
       t.it('noArgs')
         .itRepeated('with length parameter', 5, 5)
@@ -657,6 +663,31 @@ describe('string', () => {
         });
       });
 
+      describe(`nanoid`, () => {
+        it('generates a valid Nano ID', () => {
+          const id = faker.string.nanoid();
+          const regex = /^[0-9a-zA-Z_-]+$/;
+          expect(id).toMatch(regex);
+        });
+
+        it('should have a default length of 21', () => {
+          const id = faker.string.nanoid();
+          expect(id).toHaveLength(21);
+        });
+
+        it('should return an empty string when length is negative', () => {
+          const id = faker.string.nanoid(-1);
+          expect(id).toBe('');
+        });
+
+        it('should return string with a length within a given range', () => {
+          const actual = faker.string.nanoid({ min: 13, max: 37 });
+
+          expect(actual.length).toBeGreaterThanOrEqual(13);
+          expect(actual.length).toBeLessThanOrEqual(37);
+        });
+      });
+
       describe('special', () => {
         it('should return a value of type string with default length of 1', () => {
           const actual = faker.string.special();