fix(diff): fix prerelease to stable version diff logic

Refactored version diff logic to handle transitions from prerelease versions
to stable versions correctly for major/minor/patch version bumps.

functions/diff.js

@@ -29,16 +29,16 @@ const diff = (version1, version2) => {
 
     // Otherwise it can be determined by checking the high version
 
-    if (highVersion.patch) {
-      // anything higher than a patch bump would result in the wrong version
-      return 'patch'
-    }
-
     if (highVersion.minor) {
       // anything higher than a minor bump would result in the wrong version
       return 'minor'
     }
 
+    if (highVersion.patch) {
+      // anything higher than a patch bump would result in the wrong version
+      return 'patch'
+    }
+
     // bumping major/minor/patch all have same result
     return 'major'
   }

test/functions/diff.js

@@ -34,6 +34,7 @@ test('diff versions test', (t) => {
     ['1.0.0-1', '2.0.0-1', 'premajor'],
     ['1.0.0-1', '1.1.0-1', 'preminor'],
     ['1.0.0-1', '1.0.1-1', 'prepatch'],
+    ['1.7.2-1', '1.8.1', 'minor'],
   ].forEach((v) => {
     const version1 = v[0]
     const version2 = v[1]