Changed alot of things.

node_modules/semver/functions/diff.js

@@ -0,0 +1,23 @@
+const parse = require('./parse')
+const eq = require('./eq')
+
+const diff = (version1, version2) => {
+  if (eq(version1, version2)) {
+    return null
+  } else {
+    const v1 = parse(version1)
+    const v2 = parse(version2)
+    const hasPre = v1.prerelease.length || v2.prerelease.length
+    const prefix = hasPre ? 'pre' : ''
+    const defaultResult = hasPre ? 'prerelease' : ''
+    for (const key in v1) {
+      if (key === 'major' || key === 'minor' || key === 'patch') {
+        if (v1[key] !== v2[key]) {
+          return prefix + key
+        }
+      }
+    }
+    return defaultResult // may be undefined
+  }
+}
+module.exports = diff