fix(number): don't ignore multipleOf in float when min=max (#3417)

2 files changed, 39 insertions, 5 deletions

diff --git a/src/modules/number/index.ts b/src/modules/number/index.ts
index f1dce04f..9381f000 100644
--- a/src/modules/number/index.ts
+++ b/src/modules/number/index.ts
@@ -113,7 +113,7 @@ export class NumberModule extends SimpleModuleBase {
    * @param options.fractionDigits The maximum number of digits to appear after the decimal point, for example `2` will round to 2 decimal points.  Only one of `multipleOf` or `fractionDigits` should be passed.
    *
    * @throws When `min` is greater than `max`.
-   * @throws When `multipleOf` is negative.
+   * @throws When `multipleOf` is not a positive number.
    * @throws When `fractionDigits` is negative.
    * @throws When `fractionDigits` and `multipleOf` is passed in the same options object.
    *
@@ -170,10 +170,6 @@ export class NumberModule extends SimpleModuleBase {
       multipleOf = fractionDigits == null ? undefined : 10 ** -fractionDigits,
     } = options;
 
-    if (max === min) {
-      return min;
-    }
-
     if (max < min) {
       throw new FakerError(`Max ${max} should be greater than min ${min}.`);
     }
diff --git a/test/modules/number.spec.ts b/test/modules/number.spec.ts
index 278baadb..60781af8 100644
--- a/test/modules/number.spec.ts
+++ b/test/modules/number.spec.ts
@@ -156,6 +156,18 @@ describe('number', () => {
         );
       });
 
+      it('throws for impossible multipleOf where min=max', () => {
+        const input = {
+          min: 11,
+          max: 11,
+          multipleOf: 10,
+        };
+
+        expect(() => faker.number.int(input)).toThrow(
+          new FakerError('No suitable integer value between 11 and 11 found.')
+        );
+      });
+
       it('should return a random number given a maximum value as Number', () => {
         const actual = faker.number.int(10);
 
@@ -391,6 +403,32 @@ describe('number', () => {
         );
       });
 
+      it('throws for impossible multipleOf', () => {
+        const input = {
+          min: 11,
+          max: 19,
+          multipleOf: 10,
+        };
+
+        expect(() => faker.number.float(input)).toThrow(
+          new FakerError(
+            'No suitable integer value between 1.1 and 1.9000000000000001 found.'
+          )
+        );
+      });
+
+      it('throws for impossible multipleOf where min=max', () => {
+        const input = {
+          min: 11,
+          max: 11,
+          multipleOf: 10,
+        };
+
+        expect(() => faker.number.float(input)).toThrow(
+          new FakerError('No suitable integer value between 1.1 and 1.1 found.')
+        );
+      });
+
       it('should not modify the input object', () => {
         expect(() =>
           faker.number.float(Object.freeze({ min: 1, max: 2 }))