feat: treat 4-component versions (e.g. pandas-stubs) as patch updates

Author: Logic-py

src/output/table.rs

@@ -216,7 +216,14 @@ fn color_updated_constraint(
             let colored = new_parts[2..].join(".").truecolor(r, g, b).to_string();
             format!("{}{}", plain, colored)
         }
-        _ => latest.to_string(),
+        _ => {
+            // diff is at component 3+ (e.g. pandas-stubs 3.0.0 → 3.0.0.260204)
+            // treat as patch: keep first two components plain, color the rest
+            let (r, g, b) = p.patch;
+            let plain = format!("{}.{}.", new_parts[0], new_parts[1]);
+            let colored = new_parts[2..].join(".").truecolor(r, g, b).to_string();
+            format!("{}{}", plain, colored)
+        }
     };
 
     // Append the upper bound dimmed if present
@@ -338,10 +345,27 @@ mod tests {
 
     #[test]
     fn test_color_updated_constraint_four_component_version() {
+        // 1.0.0.0 → 1.0.0.1: plain prefix "1.0." + patch-colored "0.1"
         let result =
             color_updated_constraint(">=1.0.0.0", "1.0.0.1", ">=1.0.0.1", &ColorScheme::Default);
-        assert!(result.contains("1.0.0.1"));
         assert!(result.contains(">="));
+        assert!(result.contains("1.0."));
+        assert!(result.contains("0.1"));
+    }
+
+    #[test]
+    fn test_color_updated_constraint_three_to_four_component() {
+        // pandas-stubs style: 3.0.0 → 3.0.0.260204 (new 4th component)
+        // plain prefix "3.0." + patch-colored "0.260204"
+        let result = color_updated_constraint(
+            ">=3.0.0",
+            "3.0.0.260204",
+            ">=3.0.0.260204",
+            &ColorScheme::Default,
+        );
+        assert!(result.contains(">="));
+        assert!(result.contains("3.0."));
+        assert!(result.contains("260204"));
     }
 
     #[test]

src/version/compare.rs

@@ -171,6 +171,18 @@ mod tests {
         assert!(!is_newer("1.0.0", "not-a-version"));
     }
 
+    #[test]
+    fn test_is_newer_four_component() {
+        // pandas-stubs style: 3.0.0.260204 is newer than 3.0.0
+        assert!(is_newer("3.0.0.260204", "3.0.0"));
+        // and newer than a prior 4-component release
+        assert!(is_newer("3.0.0.260204", "3.0.0.250204"));
+        // same 4-component version is not newer
+        assert!(!is_newer("3.0.0.260204", "3.0.0.260204"));
+        // older 4-component is not newer than current
+        assert!(!is_newer("3.0.0.250204", "3.0.0.260204"));
+    }
+
     #[test]
     fn test_classify_bump_major() {
         assert_eq!(classify_bump("1.0.0", "2.0.0"), BumpKind::Major);
@@ -188,6 +200,61 @@ mod tests {
     fn test_classify_bump_patch() {
         assert_eq!(classify_bump("1.0.0", "1.0.1"), BumpKind::Patch);
         assert_eq!(classify_bump("7.3.0", "7.3.1"), BumpKind::Patch);
+        // 4-component versions (e.g. pandas-stubs 3.0.0 → 3.0.0.260204)
+        assert_eq!(classify_bump("3.0.0", "3.0.0.260204"), BumpKind::Patch);
+        assert_eq!(classify_bump("3.0.0.250204", "3.0.0.260204"), BumpKind::Patch);
+    }
+
+    #[tokio::test]
+    async fn test_check_dep_four_component_update() {
+        // pandas-stubs pattern: current >=3.0.0, latest 3.0.0.260204
+        use wiremock::matchers::{method, path};
+        use wiremock::{Mock, MockServer, ResponseTemplate};
+
+        let server = MockServer::start().await;
+        Mock::given(method("GET"))
+            .and(path("/pypi/pandas-stubs/json"))
+            .respond_with(ResponseTemplate::new(200).set_body_json(serde_json::json!({
+                "info": { "version": "3.0.0.260204" }
+            })))
+            .mount(&server)
+            .await;
+
+        let client = PypiClient::with_base_url(&server.uri()).unwrap();
+        let dep = crate::parsers::Dependency {
+            name: "pandas-stubs".to_string(),
+            constraint: ">=3.0.0".to_string(),
+        };
+        let update = check_dep(&client, &dep).await.unwrap().unwrap();
+        assert_eq!(update.latest, "3.0.0.260204");
+        assert_eq!(update.bump_kind, BumpKind::Patch);
+        assert_eq!(update.updated_constraint, ">=3.0.0.260204");
+    }
+
+    #[tokio::test]
+    async fn test_check_dep_four_component_to_four_component() {
+        // pandas-stubs: current >=3.0.0.250204, latest 3.0.0.260204
+        use wiremock::matchers::{method, path};
+        use wiremock::{Mock, MockServer, ResponseTemplate};
+
+        let server = MockServer::start().await;
+        Mock::given(method("GET"))
+            .and(path("/pypi/pandas-stubs/json"))
+            .respond_with(ResponseTemplate::new(200).set_body_json(serde_json::json!({
+                "info": { "version": "3.0.0.260204" }
+            })))
+            .mount(&server)
+            .await;
+
+        let client = PypiClient::with_base_url(&server.uri()).unwrap();
+        let dep = crate::parsers::Dependency {
+            name: "pandas-stubs".to_string(),
+            constraint: ">=3.0.0.250204".to_string(),
+        };
+        let update = check_dep(&client, &dep).await.unwrap().unwrap();
+        assert_eq!(update.latest, "3.0.0.260204");
+        assert_eq!(update.bump_kind, BumpKind::Patch);
+        assert_eq!(update.updated_constraint, ">=3.0.0.260204");
     }
 
     // check_dep and find_updates - network paths covered via wiremock.

src/version/constraint.rs

@@ -176,6 +176,15 @@ mod tests {
         assert_eq!(extract_base_version(""), None);
         assert_eq!(extract_base_version(">=1.0,<2.0"), Some("1.0".to_string()));
         assert_eq!(extract_base_version("~7.3.0"), Some("7.3.0".to_string()));
+        // 4-component (pandas-stubs style)
+        assert_eq!(
+            extract_base_version(">=3.0.0.250204"),
+            Some("3.0.0.250204".to_string())
+        );
+        assert_eq!(
+            extract_base_version("==3.0.0.260204"),
+            Some("3.0.0.260204".to_string())
+        );
     }
 
     #[test]
@@ -194,6 +203,15 @@ mod tests {
         assert_eq!(update_constraint("^1.10.0", "2.6.0"), "^2.6.0");
         assert_eq!(update_constraint("0.1.6", "0.3.0"), "0.3.0");
         assert_eq!(update_constraint("*", "1.0.0"), "*");
+        // 4-component new version (pandas-stubs style)
+        assert_eq!(
+            update_constraint(">=3.0.0", "3.0.0.260204"),
+            ">=3.0.0.260204"
+        );
+        assert_eq!(
+            update_constraint(">=3.0.0.250204", "3.0.0.260204"),
+            ">=3.0.0.260204"
+        );
     }
 
     #[test]