fix: refine stability precedence to support standard prerelease sorting

v4/semver.go

@@ -470,21 +470,19 @@ func (v versionExtension) Compare(o versionExtension) int {
 
 	// 2. Handle Numeric vs Alphanumeric
 	// Identify segments containing pre-release identifiers (rc, alpha, beta).
-	isPreReleaseLabel := func(s string) bool {
-		sl := strings.ToLower(s)
-		return strings.Contains(sl, "rc") || (strings.Contains(sl, "-") &&
-			(strings.Contains(sl, "alpha") || strings.Contains(sl, "beta")))
+	isStabilityLabel := func(s string) bool {
+		return strings.Contains(s, "-")
 	}
 
 	if v.IsNum && !o.IsNum {
-		if isPreReleaseLabel(o.VersionStr) {
-			return 1 // Stability Priority: Stable > Pre-release
+		if isStabilityLabel(o.VersionStr) {
+			return 1 // Number wins against an RC/Alpha/Beta string
 		}
 		return -1 // Standard SemVer: Number < String
 	}
 	if !v.IsNum && o.IsNum {
-		if isPreReleaseLabel(v.VersionStr) {
-			return -1 // Stability Priority: Pre-release < Stable
+		if isStabilityLabel(v.VersionStr) {
+			return -1 // RC/Alpha/Beta string loses against a Number
 		}
 		return 1 // Standard SemVer: String > Number
 	}
@@ -494,20 +492,6 @@ func (v versionExtension) Compare(o versionExtension) int {
 		return 0
 	}
 
-	// Pre-release marker check for string-vs-string
-	isPre := func(s string) bool {
-		sl := strings.ToLower(s)
-		return strings.Contains(sl, "rc") || strings.Contains(sl, "alpha") || strings.Contains(sl, "beta")
-	}
-
-	preV, preO := isPre(v.VersionStr), isPre(o.VersionStr)
-	if preV != preO {
-		if preV {
-			return -1
-		}
-		return 1
-	}
-
 	// Natural sort fallback for generic segments (e.g. "9-fips" vs "10-fips")
 	if naturalLess(v.VersionStr, o.VersionStr) {
 		return -1

v4/semver_test.go

@@ -597,6 +597,16 @@ func TestEdgeCases_NaturalSortAndMetadata(t *testing.T) {
 
 		// 3. Mixed Alphanumeric: abc2 should be less than abc10
 		{"1.0.0+abc2", "1.0.0+abc10", -1, "Natural sort: abc2 should be less than abc10"},
+
+		// 4. Vendir Compatibility (The new case pre < rc)
+		{"0.0.1-pre.1", "0.0.1-rc.0", -1, "Vendir: pre < rc alphabetically"},
+
+		// 5. Standard SemVer: Numeric segments are always less than alphanumeric ones
+		// Compares segment '1' (Numeric) vs segment 'beta' (Alphanumeric)
+		{"1.0.0-alpha.1", "1.0.0-alpha.beta", -1, "Standard: numeric < alphanumeric"},
+
+		// 6. Stability Check: Ensure alpha/beta without hyphens follow standard rules
+		{"1.0.0-beta", "1.0.0-rc", -1, "Standard: beta < rc alphabetically as segments have no internal hyphens"},
 	}
 
 	for _, tt := range tests {