From f99204184c8b96f499f6e7efbffb8b6b4ea8c93f Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Tue, 1 Jul 2025 09:34:22 -0700
Subject: Add memstack

---
 memstack/test/memstack_test.c | 107 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 memstack/test/memstack_test.c

(limited to 'memstack/test/memstack_test.c')

diff --git a/memstack/test/memstack_test.c b/memstack/test/memstack_test.c
new file mode 100644
index 0000000..5e9b493
--- /dev/null
+++ b/memstack/test/memstack_test.c
@@ -0,0 +1,107 @@
+#include "memstack.h"
+
+#include "test.h"
+
+#define NUM_INTS 10
+#define CAPACITY (NUM_INTS * sizeof(int))
+
+// Create and destroy a statically-backed stack.
+TEST_CASE(memstack_create) {
+  int memory[CAPACITY];
+
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, memory);
+  memstack_del(&stack);
+}
+
+// Create and destroy a dynamically-backed stack.
+TEST_CASE(mem_create_dyn) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+  memstack_del(&stack);
+}
+
+// Allocate all N ints.
+TEST_CASE(memstack_allocate_until_full) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+  }
+
+  TEST_TRUE(memstack_size(&stack) == CAPACITY);
+}
+
+// Allocate all N ints, then free them.
+TEST_CASE(memstack_fill_then_free) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  int* blocks[NUM_INTS] = {nullptr};
+  for (int i = 0; i < NUM_INTS; ++i) {
+    blocks[i] = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(blocks[i] != nullptr);
+  }
+
+  memstack_clear(&stack);
+
+  TEST_EQUAL(memstack_size(&stack), 0);
+}
+
+// Attempt to allocate blocks past the maximum stack size.
+// The stack should handle the failed allocations gracefully.
+TEST_CASE(memstack_allocate_beyond_max_size) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+  memstack_enable_traps(&stack, false);
+
+  // Fully allocate the stack.
+  for (int i = 0; i < NUM_INTS; ++i) {
+    TEST_TRUE(memstack_alloc(&stack, sizeof(int)) != nullptr);
+  }
+
+  // Past the end.
+  for (int i = 0; i < NUM_INTS; ++i) {
+    TEST_EQUAL(memstack_alloc(&stack, sizeof(int)), nullptr);
+  }
+
+  TEST_TRUE(memstack_size(&stack) == CAPACITY);
+}
+
+// Free blocks should always remain zeroed out.
+// This tests the invariant right after creating the stack.
+TEST_CASE(memstack_zero_free_blocks_after_creation) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+    TEST_EQUAL(*block, 0);
+  }
+}
+
+// Free blocks should always remain zeroed out.
+// This tests the invariant after clearing the stack and allocating a new block.
+TEST_CASE(memstack_zero_free_block_after_free) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+    TEST_EQUAL(*block, 0);
+  }
+
+  memstack_clear(&stack);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+    TEST_EQUAL(*block, 0);
+  }
+}
+
+int main() { return 0; }
-- 
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