fix: datatype.number when min = max + precision, throw when max > min (#664)

3 files changed, 20 insertions, 26 deletions

diff --git a/src/address.ts b/src/address.ts
index 5a130cb2..264b0281 100644
--- a/src/address.ts
+++ b/src/address.ts
@@ -407,8 +407,8 @@ export class Address {
   latitude(max: number = 90, min: number = -90, precision: number = 4): string {
     return this.faker.datatype
       .number({
-        max: max,
-        min: min,
+        min,
+        max,
         precision: parseFloat((0.0).toPrecision(precision) + '1'),
       })
       .toFixed(precision);
diff --git a/src/datatype.ts b/src/datatype.ts
index ad37c3da..79b0b61c 100644
--- a/src/datatype.ts
+++ b/src/datatype.ts
@@ -20,9 +20,11 @@ export class Datatype {
    *
    * @param options Maximum value or options object.
    * @param options.min Lower bound for generated number. Defaults to `0`.
-   * @param options.max Upper bound for generated number. Defaults to `99999`.
+   * @param options.max Upper bound for generated number. Defaults to `min + 99999`.
    * @param options.precision Precision of the generated number. Defaults to `1`.
    *
+   * @throws When options define `max < min`
+   *
    * @example
    * faker.datatype.number() // 55422
    * faker.datatype.number(100) // 52
@@ -34,25 +36,14 @@ export class Datatype {
   number(
     options?: number | { min?: number; max?: number; precision?: number }
   ): number {
-    if (typeof options === 'number') {
-      options = { max: options };
-    }
+    const opts = typeof options === 'number' ? { max: options } : options ?? {};
 
-    options = options ?? {};
-
-    let max = 99999;
-    let min = 0;
-    let precision = 1;
-    if (typeof options.min === 'number') {
-      min = options.min;
-    }
-
-    if (typeof options.max === 'number') {
-      max = options.max;
-    }
+    const min = typeof opts.min === 'number' ? opts.min : 0;
+    let max = typeof opts.max === 'number' ? opts.max : min + 99999;
+    const precision = typeof opts.precision === 'number' ? opts.precision : 1;
 
-    if (typeof options.precision === 'number') {
-      precision = options.precision;
+    if (max < min) {
+      throw new Error(`Max ${max} should be larger then min ${min}`);
     }
 
     // Make the range inclusive of the max value
@@ -60,13 +51,12 @@ export class Datatype {
       max += precision;
     }
 
-    let randomNumber = Math.floor(
+    const randomNumber = Math.floor(
       this.faker.mersenne.rand(max / precision, min / precision)
     );
-    // Workaround problem in Float point arithmetics for e.g. 6681493 / 0.01
-    randomNumber = randomNumber / (1 / precision);
 
-    return randomNumber;
+    // Workaround problem in float point arithmetics for e.g. 6681493 / 0.01
+    return randomNumber / (1 / precision);
   }
 
   /**
diff --git a/src/random.ts b/src/random.ts
index 0a3b3c5e..f41a67fa 100644
--- a/src/random.ts
+++ b/src/random.ts
@@ -107,8 +107,12 @@ export class Random {
   arrayElement<T = string>(
     array: ReadonlyArray<T> = ['a', 'b', 'c'] as unknown as ReadonlyArray<T>
   ): T {
-    const r = this.faker.datatype.number({ max: array.length - 1 });
-    return array[r];
+    const index =
+      array.length > 1
+        ? this.faker.datatype.number({ max: array.length - 1 })
+        : 0;
+
+    return array[index];
   }
 
   /**