diff --git a/ostd/algorithm.hh b/ostd/algorithm.hh
index 5a7152c..a7c9991 100644
--- a/ostd/algorithm.hh
+++ b/ostd/algorithm.hh
@@ -24,8 +24,16 @@
 #include <type_traits>
 #include <algorithm>
 
+#ifdef OSTD_BUILD_TESTS
+#include <vector>
+#endif
+
+#include "ostd/unit_test.hh"
+
 #include "ostd/range.hh"
 
+#define OSTD_TEST_MODULE libostd_algorithm
+
 namespace ostd {
 
 /** @addtogroup Ranges
@@ -103,6 +111,37 @@ inline auto is_partitioned(Predicate &&pred) {
     };
 }
 
+#ifdef OSTD_BUILD_TESTS
+OSTD_UNIT_TEST {
+    using ostd::test::fail_if;
+    using ostd::test::fail_if_not;
+    /* test with two vectors for pipeable and non-pipeable */
+    std::vector<int> v1 = { 5, 15, 10, 8, 36, 24 };
+    std::vector<int> v2 = v1;
+    auto try_test = [](auto &v, auto h) {
+        for (auto i: h) {
+            fail_if(i < 15);
+        }
+        for (auto i: iter(v).take(v.size() - h.size())) {
+            fail_if(i >= 15);
+        }
+    };
+    /* assume they're not partitioned */
+    fail_if(is_partitioned(iter(v1), [](int &i) { return i < 15; }));
+    fail_if(iter(v1) | is_partitioned([](int &i) { return i < 15; }));
+    fail_if(is_partitioned(iter(v2), [](int &i) { return i < 15; }));
+    fail_if(iter(v2) | is_partitioned([](int &i) { return i < 15; }));
+    /* partition now */
+    try_test(v1, partition(iter(v1), [](int &i) { return i < 15; }));
+    try_test(v2, iter(v2) | partition([](int &i) { return i < 15; }));
+    /* assume partitioned */
+    fail_if_not(is_partitioned(iter(v1), [](int &i) { return i < 15; }));
+    fail_if_not(iter(v1) | is_partitioned([](int &i) { return i < 15; }));
+    fail_if_not(is_partitioned(iter(v2), [](int &i) { return i < 15; }));
+    fail_if_not(iter(v2) | is_partitioned([](int &i) { return i < 15; }));
+}
+#endif
+
 /* sorting */
 
 namespace detail {
@@ -1396,6 +1435,8 @@ inline auto filter(Predicate &&pred) {
 
 } /* namespace ostd */
 
+#undef OSTD_TEST_MODULE
+
 #endif
 
 /** @} */
diff --git a/ostd/range.hh b/ostd/range.hh
index 3a62e7e..c82a6ad 100644
--- a/ostd/range.hh
+++ b/ostd/range.hh
@@ -1332,7 +1332,9 @@ inline auto range(T v) {
     return detail::number_range<T>(v);
 }
 
-OSTD_UNIT_TEST({
+#ifdef OSTD_BUILD_TESTS
+OSTD_UNIT_TEST {
+    using ostd::test::fail_if;
     auto r = range(5, 10, 2);
     fail_if(r.empty() || (r.front() != 5));
     r.pop_front();
@@ -1341,7 +1343,8 @@ OSTD_UNIT_TEST({
     fail_if(r.empty() || (r.front() != 9));
     r.pop_front();
     fail_if(!r.empty());
-});
+};
+#endif
 
 namespace detail {
     template<typename T>
diff --git a/ostd/unit_test.hh b/ostd/unit_test.hh
index a629fb2..a938066 100644
--- a/ostd/unit_test.hh
+++ b/ostd/unit_test.hh
@@ -47,6 +47,7 @@ namespace test {
 
 namespace detail {
     static std::vector<void (*)()> test_cases;
+    static void (*test_dummy)() = nullptr;
 
     static bool add_test(std::string testn, void (*func)()) {
         if (testn == OSTD_TEST_MODULE_CURRENT) {
@@ -58,7 +59,13 @@ namespace detail {
     struct test_error {};
 }
 
+#define OSTD_TEST_FUNC_CONCAT(p, m, l) p##_##m##_##line
+#define OSTD_TEST_FUNC_NAME(p, m, l) OSTD_TEST_FUNC_CONCAT(p, m, l)
+
 /** @brief Defines a unit test.
+ *
+ * The body of the test follows the expansion of this macro like a
+ * normal function body.
  *
  * The test is only enabled if the module name matches the value of the
  * `OSTD_BUILD_TESTS` macro, defined before inclusion of this header. The
@@ -66,14 +73,14 @@ namespace detail {
  * name is defined using the `OSTD_TEST_MODULE` macro, which should be defined
  * after including any headers and undefined at the end of the file.
  */
-#define OSTD_UNIT_TEST(body) \
-static bool test_case_##OSTD_TEST_MODULE##_##__LINE__ = \
-    ostd::test::detail::add_test(
-        OSTD_TEST_MODULE_STR(OSTD_TEST_MODULE), []() { \
-            using namespace ostd::test; \
-            body \
-        } \
-    );
+#define OSTD_UNIT_TEST \
+static void OSTD_TEST_FUNC_NAME(test_func, OSTD_TEST_MODULE, __LINE__)(); \
+static bool OSTD_TEST_FUNC_NAME(test_case, OSTD_TEST_MODULE, __LINE__) = \
+    ostd::test::detail::add_test( \
+        OSTD_TEST_MODULE_STR(OSTD_TEST_MODULE), \
+        &OSTD_TEST_FUNC_NAME(test_func, OSTD_TEST_MODULE, __LINE__) \
+    ); \
+static void OSTD_TEST_FUNC_NAME(test_func, OSTD_TEST_MODULE, __LINE__)()
 
 /** @brief Makes the test fail if the given value is true.
  *
@@ -133,10 +140,6 @@ std::pair<std::size_t, std::size_t> run() {
     return std::make_pair(succ, fail);
 }
 
-#else /* OSTD_BUILD_TESTS */
-
-#define OSTD_UNIT_TEST(body)
-
 #endif /* OSTD_BUILD_TESTS */
 
 /** @} */
diff --git a/test_runner.cc b/test_runner.cc
index 8763c59..ba13638 100644
--- a/test_runner.cc
+++ b/test_runner.cc
@@ -148,7 +148,11 @@ int main() {
             );
 
             remove(exepath.data());
-            ++nsuccess;
+            if (fail) {
+                ++nfailed;
+            } else {
+                ++nsuccess;
+            }
         });
     }