test(coverage): batch 5.5 — local_ai/{core,gif_decision}

- local_ai/core.rs: 33.33% (pins model_artifact_path structure: models/local-ai dir, `.ollama` suffix, colon→dash normalisation for Windows-safe filenames; Arc sharing across global() calls)
- local_ai/gif_decision.rs: 44.04% (trim whitespace in parse, length/word-count boundary cases, tenor_search empty-query guard, local_ai_should_send_gif empty-message early return)

10 new deterministic tests. Refs tinyhumansai#530.

Author: CodeGhost21

src/openhuman/local_ai/core.rs

@@ -26,3 +26,54 @@ pub fn model_artifact_path(config: &Config) -> PathBuf {
         .join("local-ai")
         .join(effective_chat_model_id(config).replace(':', "-") + ".ollama")
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn model_artifact_path_includes_models_local_ai_subdirs() {
+        let config = Config::default();
+        let path = model_artifact_path(&config);
+        let path_str = path.to_string_lossy();
+        assert!(
+            path_str.contains("models"),
+            "expected `models` in path: {path_str}"
+        );
+        assert!(
+            path_str.contains("local-ai"),
+            "expected `local-ai` subdir in path: {path_str}"
+        );
+    }
+
+    #[test]
+    fn model_artifact_path_ends_with_ollama_suffix() {
+        let config = Config::default();
+        let path = model_artifact_path(&config);
+        assert_eq!(
+            path.extension().and_then(|s| s.to_str()),
+            Some("ollama"),
+            "model artifact must have `.ollama` extension: {}",
+            path.display()
+        );
+    }
+
+    #[test]
+    fn model_artifact_path_replaces_colon_in_model_id_with_dash() {
+        // Model IDs commonly look like `qwen2:1.5b`; colons are illegal on
+        // Windows path components, so we normalise to `-`. This test pins
+        // that mapping.
+        let config = Config::default();
+        let path = model_artifact_path(&config);
+        let file = path.file_name().unwrap().to_string_lossy().to_string();
+        assert!(!file.contains(':'), "filename must not contain `:`: {file}");
+    }
+
+    #[test]
+    fn global_returns_same_arc_across_calls() {
+        let config = Config::default();
+        let a = global(&config);
+        let b = global(&config);
+        assert!(Arc::ptr_eq(&a, &b), "global() must return a shared Arc");
+    }
+}

src/openhuman/local_ai/gif_decision.rs

@@ -259,4 +259,59 @@ mod tests {
         let d = parse_gif_response("no gif");
         assert!(!d.should_send_gif);
     }
+
+    #[test]
+    fn parse_trims_surrounding_whitespace() {
+        let d = parse_gif_response("   NONE   ");
+        assert!(!d.should_send_gif);
+
+        let d = parse_gif_response("  hello wave  ");
+        assert!(d.should_send_gif);
+        assert_eq!(d.search_query.as_deref(), Some("hello wave"));
+    }
+
+    #[test]
+    fn parse_reject_over_eighty_chars_even_if_word_count_small() {
+        // 8 words but ≥ 80 chars is still rejected — protects against
+        // words that are URL-like or extremely long.
+        let long_word = "x".repeat(90);
+        let d = parse_gif_response(&long_word);
+        assert!(!d.should_send_gif);
+    }
+
+    #[test]
+    fn parse_reject_more_than_eight_words() {
+        let nine_words = "one two three four five six seven eight nine";
+        let d = parse_gif_response(nine_words);
+        assert!(!d.should_send_gif);
+    }
+
+    #[test]
+    fn parse_accepts_boundary_eight_words() {
+        // Exactly 8 words: accepted.
+        let eight = "one two three four five six seven eight";
+        let d = parse_gif_response(eight);
+        assert!(d.should_send_gif);
+    }
+
+    // ── tenor_search guard paths ─────────────────────────────────
+
+    #[tokio::test]
+    async fn tenor_search_rejects_empty_query() {
+        let config = crate::openhuman::config::Config::default();
+        let err = tenor_search(&config, "   ", Some(5)).await.unwrap_err();
+        assert!(err.contains("query is required"));
+    }
+
+    // ── local_ai_should_send_gif early-returns ──────────────────
+
+    #[tokio::test]
+    async fn should_send_gif_returns_false_for_empty_message() {
+        let config = crate::openhuman::config::Config::default();
+        let outcome = local_ai_should_send_gif(&config, "   ", "slack")
+            .await
+            .unwrap();
+        assert!(!outcome.value.should_send_gif);
+        assert!(outcome.logs.iter().any(|l| l.contains("empty message")));
+    }
 }