changes

crates/config/tests/loader/rejection_test.rs

@@ -0,0 +1,47 @@
+use figment::Jail;
+
+use config::load;
+
+const CONFIG_FILE: &str = "config.toml";
+
+#[test]
+fn a_malformed_file_is_refused_rather_than_ignored() {
+    Jail::expect_with(|jail| {
+        jail.create_file(CONFIG_FILE, "[server\nport = ")?;
+
+        assert!(load().is_err());
+        Ok(())
+    });
+}
+
+#[test]
+fn a_value_of_the_wrong_type_is_refused() {
+    Jail::expect_with(|jail| {
+        jail.set_env("KMOOD_SERVER__PORT", "not-a-port");
+
+        assert!(load().is_err());
+        Ok(())
+    });
+}
+
+#[test]
+fn a_refusal_names_the_key_at_fault() {
+    Jail::expect_with(|jail| {
+        jail.set_env("KMOOD_SERVER__PORT", "not-a-port");
+
+        let message = load().unwrap_err().to_string().to_lowercase();
+
+        assert!(message.contains("port"), "unhelpful message: {message}");
+        Ok(())
+    });
+}
+
+#[test]
+fn a_named_file_that_is_missing_is_refused_rather_than_ignored() {
+    Jail::expect_with(|jail| {
+        jail.set_env("KMOOD_CONFIG_FILE", "nowhere.toml");
+
+        assert!(load().is_err());
+        Ok(())
+    });
+}