feat(backend): allow version_expr to post-process version_regex results

registry/oc.toml

@@ -7,6 +7,7 @@ full = "http:oc"
 
 [backends.options]
 bin = "oc"
+version_expr = 'sortVersions(versions)'
 version_list_url = "https://mirror.openshift.com/pub/openshift-v4/clients/ocp/"
 version_regex = 'href="(\d+\.\d+\.\d+)/"'
 

registry/openshift-install.toml

@@ -7,6 +7,7 @@ full = "http:openshift-install"
 
 [backends.options]
 bin = "openshift-install"
+version_expr = 'sortVersions(versions)'
 version_list_url = "https://mirror.openshift.com/pub/openshift-v4/clients/ocp/"
 version_regex = 'href="(\d+\.\d+\.\d+)/"'
 

src/backend/version_list.rs

@@ -52,14 +52,9 @@ pub fn parse_version_list(
     let mut versions = Vec::new();
     let trimmed = content.trim();
 
-    // If an expr is provided, use it to evaluate and extract versions
-    // Fail hard if the expression is invalid - don't silently fall through
-    if let Some(expr_str) = version_expr {
-        versions = eval_version_expr(expr_str, trimmed)?;
-    }
     // If a JSON path is provided (like ".[].version" or ".versions"), try to use it
     // but fall back to text parsing if JSON parsing fails
-    else if let Some(json_path) = version_json_path {
+    if let Some(json_path) = version_json_path {
         if let Ok(json) = serde_json::from_str::<serde_json::Value>(trimmed)
             && let Ok(extracted) = jq::extract(&json, json_path)
         {
@@ -119,16 +114,29 @@ pub fn parse_version_list(
 
     // DO NOT sort versions here - the backend/upstream determines version order.
     // Sorting is handled elsewhere (e.g., versions host, resolve logic).
+    // When a registry entry needs explicit sorting, it can use version_expr
+    // (e.g. sortVersions) to post-process the extracted versions.
+    // When no other extraction method produced results, the expr operates on
+    // `body` alone (the original behavior).
+    if let Some(expr_str) = version_expr {
+        versions = eval_version_expr(expr_str, trimmed, &versions)?;
+    }
 
     Ok(versions)
 }
 
-/// Evaluate a version expression using expr-lang
-fn eval_version_expr(expr_str: &str, body: &str) -> Result<Vec<String>> {
+/// Evaluate a version expression using expr-lang.
+/// The previously extracted version list is always injected as a `versions`
+/// variable so the expression can post-process it (e.g. sortVersions).
+fn eval_version_expr(expr_str: &str, body: &str, versions: &[String]) -> Result<Vec<String>> {
     use versions::Versioning;
 
     let mut ctx = Context::default();
     ctx.insert("body".to_string(), Value::String(body.to_string()));
+    ctx.insert(
+        "versions".to_string(),
+        Value::Array(versions.iter().map(|v| Value::String(v.clone())).collect()),
+    );
 
     // expr-lang 1.0+ has built-in fromJSON, keys, values, len, toJSON functions
     let mut env = Environment::new();
@@ -410,4 +418,18 @@ mod tests {
         .unwrap();
         assert_eq!(versions, vec!["1.0.0", "1.1.0", "1.2.0-rc1"]);
     }
+
+    #[test]
+    fn test_parse_with_regex_and_version_expr_pipeline() {
+        let content =
+            r#"<a href="4.9.9/">4.9.9</a><a href="4.21.3/">4.21.3</a><a href="4.10.1/">4.10.1</a>"#;
+        let versions = parse_version_list(
+            content,
+            Some(r#"href="(\d+\.\d+\.\d+)/""#),
+            None,
+            Some("sortVersions(versions)"),
+        )
+        .unwrap();
+        assert_eq!(versions, vec!["4.9.9", "4.10.1", "4.21.3"]);
+    }
 }