test: add tests to sqlite_load_by_class function

01.workspace/heave/src/fun/sqlite_load_by_class.rs

@@ -31,24 +31,77 @@ pub fn run(path: &path::Path, entity_class: &str) -> Result<Vec<Entity>, FailedT
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::{fun, str::value::Value};
+    use std::{fs, path::Path};
+    fn setup_db(db_path: &Path) {
+        let _ = fs::remove_file(db_path);
+        fun::sqlite_init_db::run(db_path).unwrap();
+        let conn = Connection::open(db_path).unwrap();
+        // Class 'c1'
+        conn.execute("INSERT INTO entity (id, class) VALUES ('e1_c1', 'c1')", [])
+            .unwrap();
+        conn.execute(
+            "INSERT INTO attribute (id, entity_id, value_text) VALUES ('a1', 'e1_c1', 'v1')",
+            [],
+        )
+        .unwrap();
+        conn.execute(
+            "INSERT INTO attribute (id, entity_id, value_int) VALUES ('a2', 'e1_c1', 1)",
+            [],
+        )
+        .unwrap();
+        conn.execute("INSERT INTO entity (id, class) VALUES ('e2_c1', 'c1')", [])
+            .unwrap();
+        // Class 'c2'
+        conn.execute("INSERT INTO entity (id, class) VALUES ('e1_c2', 'c2')", [])
+            .unwrap();
+    }
     #[test]
     fn load_by_class_should_fetch_all_entities_for_a_given_class() {
         // Verifies that all entities belonging to a specific class are retrieved from the database.
-        todo!();
+        let db_path = Path::new("test_fetch_by_class.db");
+        setup_db(db_path);
+        let result = run(db_path, "c1");
+        assert!(result.is_ok());
+        let entities = result.unwrap();
+        assert_eq!(entities.len(), 2);
+        let ids: Vec<_> = entities.iter().map(|e| e.id.clone()).collect();
+        assert!(ids.contains(&"e1_c1".to_string()));
+        assert!(ids.contains(&"e2_c1".to_string()));
+        fs::remove_file(db_path).unwrap();
     }
     #[test]
     fn load_by_class_should_return_empty_vec_for_non_existent_class() {
         // Ensures that an empty vector is returned when querying for a class that has no entities in the database.
-        todo!();
+        let db_path = Path::new("test_non_existent_class.db");
+        setup_db(db_path);
+        let result = run(db_path, "non_existent");
+        assert!(result.is_ok());
+        let entities = result.unwrap();
+        assert!(entities.is_empty());
+        fs::remove_file(db_path).unwrap();
     }
     #[test]
     fn load_by_class_should_fully_load_entities_with_attributes() {
         // Checks that the retrieved entities are complete, including all their associated attributes.
-        todo!();
+        let db_path = Path::new("test_fully_load.db");
+        setup_db(db_path);
+        let entities = run(db_path, "c1").unwrap();
+        let entity1 = entities.iter().find(|e| e.id == "e1_c1").unwrap();
+        assert_eq!(entity1.attributes.len(), 2);
+        assert!(entity1.attributes.contains_key("a1"));
+        assert!(entity1.attributes.contains_key("a2"));
+        let attr1 = entity1.attributes.get("a1").unwrap();
+        assert_eq!(attr1.value, Value::Text("v1".to_string()));
+        let attr2 = entity1.attributes.get("a2").unwrap();
+        assert_eq!(attr2.value, Value::SignedInt(1));
+        fs::remove_file(db_path).unwrap();
     }
     #[test]
     fn load_by_class_should_fail_gracefully_on_db_connection_error() {
         // Tests that the function returns an appropriate error if the database connection cannot be established.
-        todo!();
+        let invalid_path = Path::new("/"); // A directory is not a valid database file
+        let result = run(invalid_path, "any_class");
+        assert!(result.is_err());
     }
 }