Add karma module + on_message hook

tests/karma.rs

@@ -0,0 +1,77 @@
+use rustbot::bot::module::{Action, Chat, Command, Module};
+use rustbot::bot::modules::karma::{parse_changes, Karma};
+
+fn chat<'a>(sender: &'a str, text: &'a str) -> Chat<'a> {
+    Chat {
+        sender,
+        reply_to: "#c",
+        text,
+        prefix: ">",
+        network: "t",
+    }
+}
+
+#[test]
+fn parses_increments_and_decrements() {
+    assert_eq!(
+        parse_changes("foo++ bar-- baz", "someone"),
+        vec![("foo".to_string(), 1), ("bar".to_string(), -1)]
+    );
+}
+
+#[test]
+fn strips_trailing_punctuation_and_parens() {
+    let c = parse_changes("nice work rust++, and (team)++!", "someone");
+    assert!(c.contains(&("rust".to_string(), 1)), "{c:?}");
+    assert!(c.contains(&("team".to_string(), 1)), "{c:?}");
+}
+
+#[test]
+fn no_self_karma_case_insensitive() {
+    assert!(parse_changes("me++", "me").is_empty());
+    assert!(parse_changes("Me++", "me").is_empty());
+}
+
+#[test]
+fn dedupes_within_a_message() {
+    assert_eq!(
+        parse_changes("foo++ foo++ foo++", "x"),
+        vec![("foo".to_string(), 1)]
+    );
+}
+
+#[test]
+fn bumps_persist_case_insensitively() {
+    let path = std::env::temp_dir().join("rubot-test-karma-a.json");
+    let _ = std::fs::remove_file(&path);
+    let mut k = Karma::with_path(path.clone());
+    k.on_message(&chat("alice", "Rust++ rust++ python--"));
+
+    let reloaded = Karma::with_path(path.clone());
+    assert_eq!(reloaded.get("rust"), 1); // deduped to one bump
+    assert_eq!(reloaded.get("RUST"), 1);
+    assert_eq!(reloaded.get("python"), -1);
+    let _ = std::fs::remove_file(&path);
+}
+
+#[test]
+fn command_reports_karma() {
+    let path = std::env::temp_dir().join("rubot-test-karma-b.json");
+    let _ = std::fs::remove_file(&path);
+    let mut k = Karma::with_path(path.clone());
+    k.on_message(&chat("a", "foo++ foo++"));
+    let cmd = Command {
+        sender: "a",
+        reply_to: "#c",
+        name: "karma",
+        args: &["foo"],
+        prefix: ">",
+        network: "t",
+    };
+    let out = match k.on_command(&cmd).as_slice() {
+        [Action::Reply(s)] => s.clone(),
+        _ => panic!("expected one reply"),
+    };
+    assert!(out.contains("foo has 1 karma"), "{out}");
+    let _ = std::fs::remove_file(&path);
+}