initial commit

tests/filter-test.cpp

@@ -0,0 +1,26 @@
+#ifndef FILTER_TEST_CPP
+#define FILTER_TEST_CPP
+#include <gtest/gtest.h>
+#include "filter.h"
+
+TEST(PT1FilterTest, InitialOutputIsZero) {
+    PT1Filter filter(0.1, 0.01);
+    EXPECT_DOUBLE_EQ(filter.update(0.0), 0.0);
+}
+
+TEST(PT1FilterTest, StepResponse) {
+    PT1Filter filter(0.1, 0.01);
+    double output = 0.0;
+    for (int i = 0; i < 100; ++i) {
+        output = filter.update(1.0);
+    }
+    EXPECT_NEAR(output, 1.0, 0.01);
+}
+
+TEST(PT1FilterTest, FilterFactorEffect) {
+    PT1Filter fastFilter(0.01, 0.01);
+    PT1Filter slowFilter(0.5, 0.01);
+    EXPECT_GT(fastFilter.update(1.0), slowFilter.update(1.0));
+}
+
+#endif // FILTER_TEST_CPP