From 6c864832f111c085d28cd30ae96039670ef44c59 Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Mon, 5 Oct 2026 16:25:07 +0200
Subject: kstd: ring_buffer: add more zero-capacity tests

---
 libs/kstd/kstd/ring_buffer.tests.cpp | 47 ++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/libs/kstd/kstd/ring_buffer.tests.cpp b/libs/kstd/kstd/ring_buffer.tests.cpp
index 2517ff7b..54120b99 100644
--- a/libs/kstd/kstd/ring_buffer.tests.cpp
+++ b/libs/kstd/kstd/ring_buffer.tests.cpp
@@ -2434,6 +2434,53 @@ SCENARIO("Ring Buffer zero capacity", "[kstd][ring_buffer]")
     }
   }
 
+  WHEN("constructing by input-iterator-pair constructor with an empty range")
+  {
+    auto first = kstd::tests::test_input_iterator{};
+    auto last = kstd::tests::test_input_iterator{};
+    auto buffer = kstd::ring_buffer<int, 0>{first, last};
+
+    THEN("the buffer is empty")
+    {
+      REQUIRE(buffer.empty());
+    }
+  }
+
+  WHEN("constructing by input-iterator-pair constructor with a range containing 1 element")
+  {
+    THEN("the constructor panics")
+    {
+      std::array<int, 1> source{1};
+      auto first = kstd::tests::test_input_iterator{source.data(), source.size()};
+      auto last = kstd::tests::test_input_iterator{};
+      REQUIRE_THROWS_MATCHES(
+          (kstd::ring_buffer<int, 0>{first, last}), kstd::tests::os_panic,
+          Catch::Matchers::Message("[KSTD] Tried to construct a ring buffer with more elements than it can support."));
+    }
+  }
+
+  WHEN("constructing by forward-iterator-pair constructor with an empty range")
+  {
+    auto source = std::forward_list<int>{};
+    auto buffer = kstd::ring_buffer<int, 0>{source.begin(), source.end()};
+
+    THEN("the buffer is empty")
+    {
+      REQUIRE(buffer.empty());
+    }
+  }
+
+  WHEN("constructing by forward-iterator-pair constructor with a range containing 1 element")
+  {
+    THEN("the constructor panics")
+    {
+      auto source = std::forward_list<int>{1};
+      REQUIRE_THROWS_MATCHES(
+          (kstd::ring_buffer<int, 0>{source.begin(), source.end()}), kstd::tests::os_panic,
+          Catch::Matchers::Message("[KSTD] Tried to construct a ring buffer with more elements than it can support."));
+    }
+  }
+
   GIVEN("A zero-capacity buffer of static operation trackers")
   {
     auto buffer = kstd::ring_buffer<kstd::tests::static_copy_move_tracker, 0>{};
-- 
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