BUGFIX: calculateExp throws errors in edge cases (#2667)

src/PersonObjects/formulas/skill.ts

@@ -5,6 +5,11 @@ import { clampNumber } from "../../utils/helpers/clampNumber";
  * stat level. Stat-agnostic (same formula for every stat)
  */
 export function calculateSkill(exp: number, mult = 1): number {
+  // Mult can be 0 in BN12 when the player has a very high SF12 level. In this case, the skill level will never change
+  // from its initial value (1 for most stats, except intelligence).
+  if (mult === 0) {
+    return 1;
+  }
   const value = Math.floor(mult * (32 * Math.log(exp + 534.6) - 200));
   return clampNumber(value, 1);
 }
@@ -12,7 +17,7 @@ export function calculateSkill(exp: number, mult = 1): number {
 export function calculateExp(skill: number, mult = 1): number {
   const floorSkill = Math.floor(skill);
   let value = Math.exp((skill / mult + 200) / 32) - 534.6;
-  if (skill === floorSkill && Number.isFinite(skill)) {
+  if (skill === floorSkill && Number.isFinite(skill) && Number.isFinite(value)) {
     // Check for floating point rounding issues that would cause the inverse
     // operation to return the wrong result.
     let calcSkill = calculateSkill(value, mult);