karma: leaderboard + rank, drop code-noise targets, atomic store writes

tests/karma.rs

@@ -75,3 +75,68 @@ fn command_reports_karma() {
     assert!(out.contains("foo has 1 karma"), "{out}");
     let _ = std::fs::remove_file(&path);
 }
+
+fn reply_of(k: &mut Karma, name: &str, args: &[&str]) -> String {
+    let cmd = Command {
+        sender: "z",
+        reply_to: "#c",
+        name,
+        args,
+        prefix: ">",
+        network: "t",
+    };
+    match k.on_command(&cmd).as_slice() {
+        [Action::Reply(s)] => s.clone(),
+        _ => panic!("expected one reply"),
+    }
+}
+
+#[test]
+fn ignores_single_char_and_numeric_targets() {
+    assert_eq!(
+        parse_changes("i++ 5++ x-- ok++", "s"),
+        vec![("ok".to_string(), 1)]
+    );
+}
+
+#[test]
+fn report_shows_rank() {
+    let path = std::env::temp_dir().join("rubot-test-karma-rank.json");
+    let _ = std::fs::remove_file(&path);
+    let mut k = Karma::with_path(path.clone());
+    k.on_message(&chat("a", "alpha++"));
+    k.on_message(&chat("b", "alpha++"));
+    k.on_message(&chat("c", "alpha++ beta++"));
+    assert!(reply_of(&mut k, "karma", &["alpha"]).contains("alpha has 3 karma (#1 of 2)"));
+    assert!(reply_of(&mut k, "karma", &["beta"]).contains("beta has 1 karma (#2 of 2)"));
+    let _ = std::fs::remove_file(&path);
+}
+
+#[test]
+fn unseen_thing_reports_no_karma() {
+    let path = std::env::temp_dir().join("rubot-test-karma-unseen.json");
+    let _ = std::fs::remove_file(&path);
+    let mut k = Karma::with_path(path.clone());
+    assert!(reply_of(&mut k, "karma", &["ghost"]).contains("no karma for 'ghost' yet"));
+    let _ = std::fs::remove_file(&path);
+}
+
+#[test]
+fn leaderboard_top_and_bottom() {
+    let path = std::env::temp_dir().join("rubot-test-karma-top.json");
+    let _ = std::fs::remove_file(&path);
+    let mut k = Karma::with_path(path.clone());
+    k.on_message(&chat("a", "high++ mid++ low--"));
+    k.on_message(&chat("b", "high++"));
+    let top = reply_of(&mut k, "karma", &[]);
+    assert!(
+        top.starts_with("karma top:") && top.contains("high (2)"),
+        "{top}"
+    );
+    let bottom = reply_of(&mut k, "karmabottom", &[]);
+    assert!(
+        bottom.starts_with("karma bottom:") && bottom.contains("low (-1)"),
+        "{bottom}"
+    );
+    let _ = std::fs::remove_file(&path);
+}