tests: add idalloc

Get the realloc() code path executed.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

tests/idalloc-test.c

+/*
+ * Copyright 2025 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "id-number-allocator.h"
+#include "weston-test-client-helper.h"
+#include "weston-test-assert.h"
+
+/*
+ * Allocating IDs without ever releasing any in between must produce a
+ * consecutive sequence starting from 1. 0 is not a valid id.
+ * Tests reallocation of the bucket array.
+ */
+TEST(test_sequential_ids)
+{
+	struct weston_idalloc *ida;
+	unsigned i;
+
+	ida = weston_idalloc_create(NULL);
+
+	for (i = 1; i < 10000; i++)
+		test_assert_u32_eq(weston_idalloc_get_id(ida), i);
+
+	/* Additional testing of lowest_free_bucket manipulation. */
+	weston_idalloc_put_id(ida, 99);
+	test_assert_u32_eq(weston_idalloc_get_id(ida), 99);
+	test_assert_u32_eq(weston_idalloc_get_id(ida), 10000);
+
+	weston_idalloc_destroy(ida);
+}

tests/meson.build

@@ -128,6 +128,7 @@ tests = [
 	{	'name': 'drm-smoke', 'run_exclusive': true },
 	{	'name': 'drm-writeback-screenshot', 'run_exclusive': true },
 	{	'name': 'event', },
+	{	'name': 'idalloc', },
 	{
 		'name': 'keyboard',
 		'sources': [