tests: move t0009-prio-queue.sh to the new unit testing framework

t/t0009-prio-queue.sh along with t/helper/test-prio-queue.c unit
tests Git's implementation of a priority queue. Migrate the
test over to the new unit testing framework to simplify debugging
and reduce test run-time. Refactor the required logic and add
a new test case in addition to porting over the original ones in
shell.

Signed-off-by: Chandra Pratap <chandrapratap3519@gmail.com>

Makefile

@@ -828,7 +828,6 @@ TEST_BUILTINS_OBJS += test-partial-clone.o
 TEST_BUILTINS_OBJS += test-path-utils.o
 TEST_BUILTINS_OBJS += test-pcre2-config.o
 TEST_BUILTINS_OBJS += test-pkt-line.o
-TEST_BUILTINS_OBJS += test-prio-queue.o
 TEST_BUILTINS_OBJS += test-proc-receive.o
 TEST_BUILTINS_OBJS += test-progress.o
 TEST_BUILTINS_OBJS += test-reach.o
@@ -1340,6 +1339,7 @@ THIRD_PARTY_SOURCES += sha1dc/%
 
 UNIT_TEST_PROGRAMS += t-basic
 UNIT_TEST_PROGRAMS += t-strbuf
+UNIT_TEST_PROGRAMS += t-prio-queue
 UNIT_TEST_PROGS = $(patsubst %,$(UNIT_TEST_BIN)/%$X,$(UNIT_TEST_PROGRAMS))
 UNIT_TEST_OBJS = $(patsubst %,$(UNIT_TEST_DIR)/%.o,$(UNIT_TEST_PROGRAMS))
 UNIT_TEST_OBJS += $(UNIT_TEST_DIR)/test-lib.o

t/helper/test-tool.c

@@ -57,7 +57,6 @@ static struct test_cmd cmds[] = {
 	{ "path-utils", cmd__path_utils },
 	{ "pcre2-config", cmd__pcre2_config },
 	{ "pkt-line", cmd__pkt_line },
-	{ "prio-queue", cmd__prio_queue },
 	{ "proc-receive", cmd__proc_receive },
 	{ "progress", cmd__progress },
 	{ "reach", cmd__reach },

t/helper/test-tool.h

@@ -50,7 +50,6 @@ int cmd__partial_clone(int argc, const char **argv);
 int cmd__path_utils(int argc, const char **argv);
 int cmd__pcre2_config(int argc, const char **argv);
 int cmd__pkt_line(int argc, const char **argv);
-int cmd__prio_queue(int argc, const char **argv);
 int cmd__proc_receive(int argc, const char **argv);
 int cmd__progress(int argc, const char **argv);
 int cmd__reach(int argc, const char **argv);

t/unit-tests/t-prio-queue.c

@@ -0,0 +1,101 @@
+#include "test-lib.h"
+#include "prio-queue.h"
+
+static int intcmp(const void *va, const void *vb, void *data UNUSED)
+{
+	const int *a = va, *b = vb;
+	return *a - *b;
+}
+
+
+#define MISSING  -1
+#define DUMP	 -2
+#define STACK	 -3
+#define GET	 -4
+#define REVERSE  -5
+
+static int show(int *v)
+{
+	return v ? *v : MISSING;
+}
+
+static int test_prio_queue(int *input, int *result)
+{
+	struct prio_queue pq = { intcmp };
+	int i = 0;
+
+	while (*input) {
+		int *val = input++;
+		void *peek, *get;
+		switch(*val) {
+			case GET:
+				peek = prio_queue_peek(&pq);
+				get = prio_queue_get(&pq);
+				if (peek != get)
+					BUG("peek and get results don't match");
+				result[i++] = show(get);
+				break;
+			case DUMP:
+				while ((peek = prio_queue_peek(&pq))) {
+					get = prio_queue_get(&pq);
+					if (peek != get)
+						BUG("peek and get results don't match");
+					result[i++] = show(get);
+				}
+				break;
+			case STACK:
+				pq.compare = NULL;
+				break;
+			case REVERSE:
+				prio_queue_reverse(&pq);
+				break;
+			default:
+				prio_queue_put(&pq, val);
+				break;
+		}
+	}
+	clear_prio_queue(&pq);
+	return 0;
+}
+
+#define BASIC_INPUT 1, 2, 3, 4, 5, 5, DUMP
+#define BASIC_EXPECTED 1, 2, 3, 4, 5, 5
+
+#define MIXED_PUT_GET_INPUT 6, 2, 4, GET, 5, 3, GET, GET, 1, DUMP
+#define MIXED_PUT_GET_EXPECTED 2, 3, 4, 1, 5, 6
+
+#define EMPTY_QUEUE_INPUT 1, 2, GET, GET, GET, 1, 2, GET, GET, GET
+#define EMPTY_QUEUE_EXPECTED 1, 2, MISSING, 1, 2, MISSING
+
+#define STACK_INPUT STACK, 1, 5, 4, 6, 2, 3, DUMP
+#define STACK_EXPECTED 3, 2, 6, 4, 5, 1
+
+#define REVERSE_STACK_INPUT STACK, 1, 2, 3, 4, 5, 6, REVERSE, DUMP
+#define REVERSE_STACK_EXPECTED 1, 2, 3, 4, 5, 6
+
+#define TEST_INPUT(INPUT, EXPECTED, name)			\
+  static void test_##name(void)				\
+{								\
+	int input[] = {INPUT};					\
+	int expected[] = {EXPECTED};				\
+	int result[ARRAY_SIZE(expected)];			\
+	test_prio_queue(input, result);				\
+	check(!memcmp(expected, result, sizeof(expected)));	\
+}
+
+TEST_INPUT(BASIC_INPUT, BASIC_EXPECTED, basic)
+TEST_INPUT(MIXED_PUT_GET_INPUT, MIXED_PUT_GET_EXPECTED, mixed)
+TEST_INPUT(EMPTY_QUEUE_INPUT, EMPTY_QUEUE_EXPECTED, empty)
+TEST_INPUT(STACK_INPUT, STACK_EXPECTED, stack)
+TEST_INPUT(REVERSE_STACK_INPUT, REVERSE_STACK_EXPECTED, reverse)
+
+int cmd_main(int argc, const char **argv)
+{
+	TEST(test_basic(), "prio-queue works for basic input");
+	TEST(test_mixed(), "prio-queue works for mixed put & get commands");
+	TEST(test_empty(), "prio-queue works when queue is empty");
+	TEST(test_stack(), "prio-queue works when used as a LIFO stack");
+	TEST(test_reverse(), "prio-queue works when LIFO stack is reversed");
+
+	return test_done();
+}