tests: net: prometheus: Make sure formatter works as expected

Enhance the formatter test to verify that two metrics can be
formatted.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

tests/net/lib/prometheus/formatter/src/main.c

@@ -13,7 +13,9 @@
 #define MAX_BUFFER_SIZE 256
 
 PROMETHEUS_COUNTER_DEFINE(test_counter, "Test counter",
-			  ({ .key = "test", .value = "counter" }));
+			  ({ .key = "test", .value = "counter" }), NULL);
+PROMETHEUS_COUNTER_DEFINE(test_counter2, "Test counter 2",
+			  ({ .key = "test", .value = "counter" }), NULL);
 
 PROMETHEUS_COLLECTOR_DEFINE(test_custom_collector);
 
@@ -28,11 +30,15 @@ ZTEST(test_formatter, test_prometheus_formatter_simple)
 	int ret;
 	char formatted[MAX_BUFFER_SIZE] = { 0 };
 	struct prometheus_counter *counter;
-	char exposed[] = "# HELP test_counter Test counter\n"
+	char exposed[] = "# HELP test_counter2 Test counter 2\n"
+			 "# TYPE test_counter2 counter\n"
+			 "test_counter2{test=\"counter\"} 1\n"
+			 "# HELP test_counter Test counter\n"
 			 "# TYPE test_counter counter\n"
 			 "test_counter{test=\"counter\"} 1\n";
 
 	prometheus_collector_register_metric(&test_custom_collector, &test_counter.base);
+	prometheus_collector_register_metric(&test_custom_collector, &test_counter2.base);
 
 	counter = (struct prometheus_counter *)prometheus_collector_get_metric(
 		&test_custom_collector, "test_counter");
@@ -44,13 +50,16 @@ ZTEST(test_formatter, test_prometheus_formatter_simple)
 	ret = prometheus_counter_inc(&test_counter);
 	zassert_ok(ret, "Error incrementing counter");
 
+	ret = prometheus_counter_inc(&test_counter2);
+	zassert_ok(ret, "Error incrementing counter 2");
+
 	zassert_equal(counter->value, 1, "Counter value is not 1");
 
 	ret = prometheus_format_exposition(&test_custom_collector, formatted, sizeof(formatted));
 	zassert_ok(ret, "Error formatting exposition data");
 
 	zassert_equal(strcmp(formatted, exposed), 0,
-		      "Exposition format is not as expected (expected \"%s\", got \"%s\")",
+		      "Exposition format is not as expected (expected\n\"%s\", got\n\"%s\")",
 		      exposed, formatted);
 }