feat(helpers): allow empty string in fake (#1679)

3 files changed, 15 insertions, 17 deletions

diff --git a/src/modules/helpers/index.ts b/src/modules/helpers/index.ts
index cb4f7680..2ccc311e 100644
--- a/src/modules/helpers/index.ts
+++ b/src/modules/helpers/index.ts
@@ -526,7 +526,7 @@ export class HelpersModule {
    *
    * It is also NOT possible to use any non-faker methods or plain javascript in such patterns.
    *
-   * @param pattern The pattern string that will get interpolated. Must not be empty.
+   * @param pattern The pattern string that will get interpolated.
    *
    * @see faker.helpers.mustache() to use custom functions for resolution.
    *
@@ -621,7 +621,7 @@ export class HelpersModule {
    *
    * It is also NOT possible to use any non-faker methods or plain javascript in such patterns.
    *
-   * @param pattern The pattern string that will get interpolated. Must not be empty. If an array is passed, a random element will be picked and interpolated.
+   * @param pattern The pattern string that will get interpolated. If an array is passed, a random element will be picked and interpolated.
    *
    * @see faker.helpers.mustache() to use custom functions for resolution.
    *
@@ -645,10 +645,6 @@ export class HelpersModule {
         throw new FakerError('Array of pattern strings cannot be empty.');
       }
     }
-    // if incoming str parameter is not provided, return error message
-    if (pattern.length === 0) {
-      throw new FakerError('Pattern string cannot be empty.');
-    }
 
     // find first matching {{ and }}
     const start = pattern.search(/{{[a-z]/);
@@ -721,10 +717,6 @@ export class HelpersModule {
     const res =
       pattern.substring(0, start) + result + pattern.substring(end + 2);
 
-    if (res === '') {
-      return '';
-    }
-
     // return the response recursively until we are done finding all tags
     return this.fake(res);
   }
diff --git a/test/__snapshots__/helpers.spec.ts.snap b/test/__snapshots__/helpers.spec.ts.snap
index 4ce31832..95ac4a03 100644
--- a/test/__snapshots__/helpers.spec.ts.snap
+++ b/test/__snapshots__/helpers.spec.ts.snap
@@ -33,6 +33,8 @@ exports[`helpers > 42 > fake > with a dynamic template 1`] = `"my string: Cky2ei
 
 exports[`helpers > 42 > fake > with a static template 1`] = `"my test string"`;
 
+exports[`helpers > 42 > fake > with empty string 1`] = `""`;
+
 exports[`helpers > 42 > fake > with multiple dynamic templates 1`] = `"Sandy"`;
 
 exports[`helpers > 42 > fake > with multiple static templates 1`] = `"B"`;
@@ -216,6 +218,8 @@ exports[`helpers > 1211 > fake > with a dynamic template 1`] = `"my string: wKti
 
 exports[`helpers > 1211 > fake > with a static template 1`] = `"my test string"`;
 
+exports[`helpers > 1211 > fake > with empty string 1`] = `""`;
+
 exports[`helpers > 1211 > fake > with multiple dynamic templates 1`] = `"La Crosse"`;
 
 exports[`helpers > 1211 > fake > with multiple static templates 1`] = `"C"`;
@@ -395,6 +399,8 @@ exports[`helpers > 1337 > fake > with a dynamic template 1`] = `"my string: 9U/4
 
 exports[`helpers > 1337 > fake > with a static template 1`] = `"my test string"`;
 
+exports[`helpers > 1337 > fake > with empty string 1`] = `""`;
+
 exports[`helpers > 1337 > fake > with multiple dynamic templates 1`] = `"U/4:SK$>6Q"`;
 
 exports[`helpers > 1337 > fake > with multiple static templates 1`] = `"A"`;
diff --git a/test/helpers.spec.ts b/test/helpers.spec.ts
index 37a1bd02..2f591fc2 100644
--- a/test/helpers.spec.ts
+++ b/test/helpers.spec.ts
@@ -96,7 +96,8 @@ describe('helpers', () => {
     });
 
     t.describe('fake', (t) => {
-      t.it('with a static template', 'my test string')
+      t.it('with empty string', '')
+        .it('with a static template', 'my test string')
         .it('with a dynamic template', 'my string: {{string.sample}}')
         .it('with multiple static templates', ['A', 'B', 'C'])
         .it('with multiple dynamic templates', [
@@ -555,6 +556,11 @@ describe('helpers', () => {
       });
 
       describe('fake()', () => {
+        it('does allow empty string input', () => {
+          const actual = faker.helpers.fake('');
+          expect(actual).toBe('');
+        });
+
         it('replaces a token with a random value for a method without parentheses', () => {
           const actual = faker.helpers.fake('{{string.numeric}}');
           expect(actual).toMatch(/^\d$/);
@@ -602,12 +608,6 @@ describe('helpers', () => {
           expect(actual).toMatch(/^\d{5}$/);
         });
 
-        it('does not allow empty string parameters', () => {
-          expect(() => faker.helpers.fake('')).toThrowError(
-            new FakerError('Pattern string cannot be empty.')
-          );
-        });
-
         it('does not allow empty array parameters', () => {
           expect(() => faker.helpers.fake([])).toThrowError(
             new FakerError('Array of pattern strings cannot be empty.')