feat: builtins.compareVersions

nix-js/tests/builtins.rs

@@ -147,3 +147,71 @@ fn builtins_concat_lists() {
         ]))
     );
 }
+
+#[test]
+fn builtins_compare_versions_basic() {
+    assert_eq!(eval("builtins.compareVersions \"1.0\" \"2.3\""), Value::Int(-1));
+    assert_eq!(eval("builtins.compareVersions \"2.1\" \"2.3\""), Value::Int(-1));
+    assert_eq!(eval("builtins.compareVersions \"2.3\" \"2.3\""), Value::Int(0));
+    assert_eq!(eval("builtins.compareVersions \"2.5\" \"2.3\""), Value::Int(1));
+    assert_eq!(eval("builtins.compareVersions \"3.1\" \"2.3\""), Value::Int(1));
+}
+
+#[test]
+fn builtins_compare_versions_components() {
+    assert_eq!(eval("builtins.compareVersions \"2.3.1\" \"2.3\""), Value::Int(1));
+    assert_eq!(eval("builtins.compareVersions \"2.3\" \"2.3.1\""), Value::Int(-1));
+}
+
+#[test]
+fn builtins_compare_versions_numeric_vs_alpha() {
+    // Numeric component comes before alpha component
+    assert_eq!(eval("builtins.compareVersions \"2.3.1\" \"2.3a\""), Value::Int(1));
+    assert_eq!(eval("builtins.compareVersions \"2.3a\" \"2.3.1\""), Value::Int(-1));
+}
+
+#[test]
+fn builtins_compare_versions_pre() {
+    // "pre" is special: comes before everything except another "pre"
+    assert_eq!(eval("builtins.compareVersions \"2.3pre1\" \"2.3\""), Value::Int(-1));
+    assert_eq!(eval("builtins.compareVersions \"2.3pre3\" \"2.3pre12\""), Value::Int(-1));
+    assert_eq!(eval("builtins.compareVersions \"2.3pre1\" \"2.3c\""), Value::Int(-1));
+    assert_eq!(eval("builtins.compareVersions \"2.3pre1\" \"2.3q\""), Value::Int(-1));
+}
+
+#[test]
+fn builtins_compare_versions_alpha() {
+    // Alphabetic comparison
+    assert_eq!(eval("builtins.compareVersions \"2.3a\" \"2.3c\""), Value::Int(-1));
+    assert_eq!(eval("builtins.compareVersions \"2.3c\" \"2.3a\""), Value::Int(1));
+}
+
+#[test]
+fn builtins_compare_versions_symmetry() {
+    // Test symmetry: compareVersions(a, b) == -compareVersions(b, a)
+    assert_eq!(
+        eval("builtins.compareVersions \"1.0\" \"2.3\""),
+        Value::Int(-1)
+    );
+    assert_eq!(
+        eval("builtins.compareVersions \"2.3\" \"1.0\""),
+        Value::Int(1)
+    );
+}
+
+#[test]
+fn builtins_compare_versions_complex() {
+    // Complex version strings with multiple components
+    assert_eq!(
+        eval("builtins.compareVersions \"1.2.3.4\" \"1.2.3.5\""),
+        Value::Int(-1)
+    );
+    assert_eq!(
+        eval("builtins.compareVersions \"1.2.10\" \"1.2.9\""),
+        Value::Int(1)
+    );
+    assert_eq!(
+        eval("builtins.compareVersions \"1.2a3\" \"1.2a10\""),
+        Value::Int(-1)
+    );
+}