Add maxSafeInteger and maxSafeNat

Fixes #285
dubzzz · Jan 23, 2019 · a8eeb16 · a8eeb16
1 parent c4d396b
commit a8eeb16
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Showing 4 changed files with 38 additions and 3 deletions.
diff --git a/documentation/Arbitraries.md b/documentation/Arbitraries.md
@@ -19,6 +19,8 @@ Integer values:
 - `fc.integer(min: number, max: number)` all possible integers between min (included) and max (included)
 - `fc.nat()` all possible positive integers ie. from 0 (included) to 2147483647 (included)
 - `fc.nat(max: number)` all possible positive integers between 0 (included) and max (included)
+- `fc.maxSafeInteger()` all possible positive integers between `Number.MIN_SAFE_INTEGER` (included) and `Number.MAX_SAFE_INTEGER` (included)
+- `fc.maxSafeNat()` all possible positive integers between 0 (included) and `Number.MAX_SAFE_INTEGER` (included)
 
 Floating point numbers:
 

diff --git a/src/check/arbitrary/IntegerArbitrary.ts b/src/check/arbitrary/IntegerArbitrary.ts
@@ -62,6 +62,13 @@ function integer(a?: number, b?: number): ArbitraryWithShrink<number> {
   return b === undefined ? new IntegerArbitrary(undefined, a) : new IntegerArbitrary(a, b);
 }
 
+/**
+ * For integers between Number.MIN_SAFE_INTEGER (included) and Number.MAX_SAFE_INTEGER (included)
+ */
+function maxSafeInteger(): ArbitraryWithShrink<number> {
+  return integer(Number.MIN_SAFE_INTEGER, Number.MAX_SAFE_INTEGER);
+}
+
 /**
  * For positive integers between 0 (included) and 2147483647 (included)
  */
@@ -75,4 +82,11 @@ function nat(a?: number): ArbitraryWithShrink<number> {
   return new IntegerArbitrary(0, a);
 }
 
-export { integer, nat };
+/**
+ * For positive integers between 0 (included) and Number.MAX_SAFE_INTEGER (included)
+ */
+function maxSafeNat(): ArbitraryWithShrink<number> {
+  return nat(Number.MAX_SAFE_INTEGER);
+}
+
+export { integer, nat, maxSafeInteger, maxSafeNat };
diff --git a/src/fast-check-default.ts b/src/fast-check-default.ts
@@ -18,7 +18,7 @@ import { dictionary } from './check/arbitrary/DictionaryArbitrary';
 import { double, float } from './check/arbitrary/FloatingPointArbitrary';
 import { frequency } from './check/arbitrary/FrequencyArbitrary';
 import { compareBooleanFunc, compareFunc, func } from './check/arbitrary/FunctionArbitrary';
-import { integer, nat } from './check/arbitrary/IntegerArbitrary';
+import { integer, maxSafeInteger, maxSafeNat, nat } from './check/arbitrary/IntegerArbitrary';
 import { lorem } from './check/arbitrary/LoremArbitrary';
 import {
   anything,
@@ -86,6 +86,8 @@ export {
   double,
   integer,
   nat,
+  maxSafeInteger,
+  maxSafeNat,
   bigIntN,
   bigUintN,
   bigInt,

diff --git a/test/unit/check/arbitrary/IntegerArbitrary.spec.ts b/test/unit/check/arbitrary/IntegerArbitrary.spec.ts
@@ -1,7 +1,7 @@
 import * as fc from '../../../../lib/fast-check';
 
 import { Shrinkable } from '../../../../src/check/arbitrary/definition/Shrinkable';
-import { integer, nat } from '../../../../src/check/arbitrary/IntegerArbitrary';
+import { integer, nat, maxSafeNat, maxSafeInteger } from '../../../../src/check/arbitrary/IntegerArbitrary';
 
 import * as genericHelper from './generic/GenericArbitraryHelper';
 
@@ -171,6 +171,15 @@ describe('IntegerArbitrary', () => {
       );
     });
   });
+  describe('maxSafeInteger', () => {
+    describe('Given no constraints [between MIN_SAFE_INTEGER and MAX_SAFE_INTEGER]', () => {
+      genericHelper.isValidArbitrary(() => maxSafeInteger(), {
+        isStrictlySmallerValue: isStrictlySmallerInteger,
+        isValidValue: (g: number) =>
+          typeof g === 'number' && g >= Number.MIN_SAFE_INTEGER && g <= Number.MAX_SAFE_INTEGER
+      });
+    });
+  });
   describe('nat', () => {
     describe('Given no constraints [between 0 and 2**31 -1]', () => {
       genericHelper.isValidArbitrary(() => nat(), {
@@ -186,4 +195,12 @@ describe('IntegerArbitrary', () => {
       });
     });
   });
+  describe('maxSafeNat', () => {
+    describe('Given no constraints [between 0 and MAX_SAFE_INTEGER]', () => {
+      genericHelper.isValidArbitrary(() => maxSafeNat(), {
+        isStrictlySmallerValue: isStrictlySmallerInteger,
+        isValidValue: (g: number) => typeof g === 'number' && g >= 0 && g <= Number.MAX_SAFE_INTEGER
+      });
+    });
+  });
 });