impemented mock testing

tests/config_merge_test.rs

@@ -0,0 +1,35 @@
+#[path = "../src/engine/formatters/throttled.rs"]
+mod throttled;
+
+use throttled::{ThrottledTranslator, ThrottledConfig};
+use std::fs;
+
+#[test]
+fn test_throttled_formatter_non_destructive() {
+    let fixture_path = "tests/fixtures/throttled.conf";
+    let existing_content = fs::read_to_string(fixture_path).expect("Failed to read fixture");
+    
+    let config = ThrottledConfig {
+        pl1_limit: 25.0,
+        pl2_limit: 35.0,
+        trip_temp: 90.0,
+    };
+
+    let merged = ThrottledTranslator::merge_conf(&existing_content, &config);
+
+    // Assert updates
+    assert!(merged.contains("PL1_Tdp_W: 25"));
+    assert!(merged.contains("PL2_Tdp_W: 35"));
+    assert!(merged.contains("Trip_Temp_C: 90"));
+
+    // Assert preservation
+    assert!(merged.contains("[UNDERVOLT]"));
+    assert!(merged.contains("CORE: -100"));
+    assert!(merged.contains("GPU: -50"));
+    assert!(merged.contains("# Important: Preserving undervolt offsets is critical!"));
+    assert!(merged.contains("Update_Interval_ms: 3000"));
+    
+    // Check that we didn't lose the [GENERAL] section
+    assert!(merged.contains("[GENERAL]"));
+    assert!(merged.contains("# This is a complex test fixture"));
+}