BUGFIX: Improve implementation of getRandomInt (#1282)

src/utils/EnumHelper.ts

@@ -4,7 +4,7 @@ import type { NetscriptContext } from "../Netscript/APIWrapper";
 import * as allEnums from "../Enums";
 import { assertString } from "../Netscript/TypeAssertion";
 import { errorMessage } from "../Netscript/ErrorMessages";
-import { getRandomInt } from "./helpers/getRandomInt";
+import { getRandomIntInclusive } from "./helpers/getRandomIntInclusive";
 
 interface GetMemberOptions {
   /** Whether to use fuzzy matching on the input (case insensitive, ignore spaces and dashes) */
@@ -69,7 +69,7 @@ class EnumHelper<EnumObj extends object, EnumMember extends Member<EnumObj> & st
   }
   // Get a random enum member
   random() {
-    const index = getRandomInt(0, this.valueArray.length - 1);
+    const index = getRandomIntInclusive(0, this.valueArray.length - 1);
     return this.valueArray[index];
   }
 }

src/utils/helpers/getRandomByte.ts

@@ -1,4 +1,4 @@
-import { getRandomInt } from "./getRandomInt";
+import { getRandomIntInclusive } from "./getRandomIntInclusive";
 
 /**
  * Gets a random value in the range of a byte (0 - 255), or up to the maximum.
@@ -9,5 +9,5 @@ export function getRandomByte(max: number): number {
   const byteMaximum = 255;
   const upper: number = Math.max(Math.min(max, byteMaximum), 0);
 
-  return getRandomInt(0, upper);
+  return getRandomIntInclusive(0, upper);
 }

src/utils/helpers/getRandomInt.ts

@@ -1,11 +0,0 @@
-/**
- * Gets a random integer bounded by the values passed in.
- * @param min The minimum value in the range.
- * @param max The maximum value in the range.
- */
-export function getRandomInt(min: number, max: number): number {
-  const lower: number = Math.min(min, max);
-  const upper: number = Math.max(min, max);
-
-  return Math.floor(Math.random() * (upper - lower + 1)) + lower;
-}

src/utils/helpers/getRandomIntInclusive.ts

@@ -0,0 +1,21 @@
+/**
+ *
+ * Gets a random integer between min (inclusive) and max (inclusive).
+ *
+ * Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random
+ *
+ * @param min The minimum value in the range.
+ * @param max The maximum value in the range.
+ */
+export function getRandomIntInclusive(min: number, max: number): number {
+  if (!Number.isInteger(min)) {
+    throw new Error(`Min is not an integer. Min: ${min}.`);
+  }
+  if (!Number.isInteger(max)) {
+    throw new Error(`Max is not an integer. Max: ${max}.`);
+  }
+  if (min > max) {
+    throw new Error(`Min is greater than max. Min: ${min}. Max: ${max}.`);
+  }
+  return Math.floor(Math.random() * (max - min + 1) + min);
+}