added test to develop branch

src/test/c/test_taschenrechner.c

@@ -14,14 +14,29 @@ void tearDown(void)
 
 void test_addition(void)
 {
-    /* arrange */
-    char* result;
-    char expected[] = "2\n";
+    doulbe result = add(1, 2);
+    TEST_ASSERT_EQUAL(3, result);
+}
+
+void test_minus(void)
+{
+    doulbe result = minus(3, 1);
+    TEST_ASSERT_EQUAL(2, result);
+}
 
-    /* act */
-    result = convert(2);
+void test_multiply(void)
+{
+    doulbe result = multiply(1, 2);
+    TEST_ASSERT_EQUAL(2, result);
+}
+
+void test_divide(void)
+{
+    doulbe result = divide(4, 2);
+    TEST_ASSERT_EQUAL(2, result);
 
-    /* assert */
+    doulbe result1 = divide(4, 0);
+    TEST_ASSERT_EQUAL(0, result1);
 }
 
 #endif // TEST