fix(action): parse gc-max-store-size correctly

- use length in characters
- add missing "break"-s

Author: deemp

src/utils/inputs.ts

@@ -15,12 +15,12 @@ export function getInputAsArray(
 export function parseNixGcMax(name: string, options?: core.InputOptions) {
     const input = core.getInput(name, options);
 
-    if (input.length == 0) {
+    const chars = [...input];
+
+    if (chars.length == 0) {
         return undefined;
     }
 
-    const chars = [...input];
-
     let result: number = 0;
 
     for (let i = 0; i < chars.length; i++) {
@@ -33,10 +33,13 @@ export function parseNixGcMax(name: string, options?: core.InputOptions) {
                 switch (char) {
                     case "K":
                         result <<= 10;
+                        break;
                     case "M":
                         result <<= 20;
+                        break;
                     case "G":
                         result <<= 30;
+                        break;
                     default:
                         result = NaN;
                 }