fix: semver.diff prerelease to release recognition

Author: dominique-blockchain

Diff for: functions/diff.js

@@ -17,6 +17,19 @@ const diff = (version1, version2) => {
         }
       }
     }
+    if (v1.major === v2.major &&
+        v1.minor === v2.minor &&
+        v1.patch === v2.patch && !(v1.prerelease.length && v2.prerelease.length)) {
+      const releaseTypes = []
+      for (const key in v1) {
+        if (key === 'major' || key === 'minor' || key === 'patch') {
+          if (v1[key]) {
+            releaseTypes.push(key)
+          }
+        }
+      }
+      return releaseTypes.pop()
+    }
     return defaultResult // may be undefined
   }
 }

Diff for: test/functions/diff.js

@@ -5,18 +5,24 @@ test('diff versions test', (t) => {
 //  [version1, version2, result]
 //  diff(version1, version2) -> result
   [['1.2.3', '0.2.3', 'major'],
+    ['0.2.3', '1.2.3', 'major'],
     ['1.4.5', '0.2.3', 'major'],
     ['1.2.3', '2.0.0-pre', 'premajor'],
+    ['2.0.0-pre', '1.2.3', 'premajor'],
     ['1.2.3', '1.3.3', 'minor'],
     ['1.0.1', '1.1.0-pre', 'preminor'],
     ['1.2.3', '1.2.4', 'patch'],
     ['1.2.3', '1.2.4-pre', 'prepatch'],
-    ['0.0.1', '0.0.1-pre', 'prerelease'],
-    ['0.0.1', '0.0.1-pre-2', 'prerelease'],
-    ['1.1.0', '1.1.0-pre', 'prerelease'],
+    ['0.0.1', '0.0.1-pre', 'patch'],
+    ['0.0.1', '0.0.1-pre-2', 'patch'],
+    ['1.1.0', '1.1.0-pre', 'minor'],
     ['1.1.0-pre-1', '1.1.0-pre-2', 'prerelease'],
     ['1.0.0', '1.0.0', null],
-
+    ['1.0.0', '1.0.0', null],
+    ['1.0.0', '1.0.0', null],
+    ['0.0.2-1', '0.0.2', 'patch'],
+    ['0.1.0-1', '0.1.0', 'minor'],
+    ['1.0.0-1', '1.0.0', 'major'],
   ].forEach((v) => {
     const version1 = v[0]
     const version2 = v[1]