GPStracker/gps-test-tool/test_malformed.c

/*
 * Malformed/edge-case NMEA regression test.
 *
 * Feeds soft/nmea.c's real gps_parse() (through the same PC_BUILD shim as
 * the rest of this test tool) a fixture of real and synthetic sentences
 * that are known to be awkward: invalid epochs from an actual hike log,
 * truncated/bad-checksum/short-dialect sentences, and a run long enough to
 * exercise the HDOP-based speed-sample gating added after that hike showed
 * a single poor-quality fix (HDOP 16, 44.8 km/h) skewing the whole-session
 * average.
 *
 * Nothing in malformed_test.nmea should crash the parser (run under a tool
 * like valgrind or ASan for a stronger guarantee than "the process exited
 * zero"), and the checks below assert the speed average is actually left
 * alone by the invalid/poor-quality samples, and is capped rather than
 * excluded for a genuinely fast, good-quality one.
 *
 * Usage: ./test-malformed [malformed_test.nmea]
 */

#define PC_BUILD
#include "main.h"

volatile struct system_s System;
struct location_s location;
time_t utc;
unsigned char FLAGS = 0;
volatile unsigned char reset_cause = 0;
FILE *debug_output = NULL;

__flash const char gnss_name_stub[] = "n/a";
__flash const char *gnss_names[] = { gnss_name_stub, gnss_name_stub, gnss_name_stub, gnss_name_stub, gnss_name_stub, gnss_name_stub };
__flash const char uart_log_mode_stub[] = "n/a";
__flash const char *uart_log_mode_names[] = { uart_log_mode_stub, uart_log_mode_stub, uart_log_mode_stub };

time_t gps_parse(const char *nmea);

char *get_iso_time(time_t time, unsigned char local) {
	(void)local;
	static char output[32];
	struct tm *ct = gmtime(&time);
	sprintf(output, "%04d-%02d-%02dT%02d:%02d:%02d.000Z",
		ct->tm_year + 1900, ct->tm_mon + 1, ct->tm_mday,
		ct->tm_hour, ct->tm_min, ct->tm_sec);
	return output;
}

void iso_time_to_filename(char *time) {
	(void)time;
}

static int failures;

static void check(int cond, const char *what) {
	if (!cond) {
		fprintf(stderr, "FAIL: %s\n", what);
		failures++;
	} else {
		printf("ok: %s\n", what);
	}
}

/* Recognize the known-invalid lines from malformed_test.nmea's section 1,
 * to check precisely that they leave the speed average alone - not just
 * that nothing crashes. */
static int is_invalid_epoch_line(const char *line) {
	return strstr(line, ",V,,,,,") != NULL				/* RMC: empty lat/lon, status V */
		|| (strstr(line, "VTG") && strstr(line, ",N*"));	/* VTG: mode indicator N (not valid) */
}

int main(int argc, char *argv[]) {
	const char *path = argc > 1 ? argv[1] : "malformed_test.nmea";
	FILE *f = fopen(path, "r");
	char raw[512];
	char line[512];
	int total_lines = 0;

	if (!f) {
		fprintf(stderr, "Cannot open %s\n", path);
		return 1;
	}

	memset((void *)&System, 0, sizeof(System));
	memset(&location, 0, sizeof(location));
	System.conf.min_sats = 4;
	utc = 0;

	while (fgets(raw, sizeof raw, f)) {
		unsigned long int count_before, accum_before;
		size_t len = strlen(raw);

		while (len && (raw[len - 1] == '\n' || raw[len - 1] == '\r'))
			raw[--len] = '\0';
		if (len == 0 || raw[0] == '#')
			continue; /* blank line or fixture comment, not fed to the parser */

		snprintf(line, sizeof line, "%s\r\n", raw);
		total_lines++;

		count_before = System.speed_sample_count;
		accum_before = System.speed_accum_x100;

		gps_parse(line); /* must not crash, regardless of how malformed the line is */

		if (is_invalid_epoch_line(raw)) {
			char what[560];
			snprintf(what, sizeof what, "no speed sample added by: %s", raw);
			check(System.speed_sample_count == count_before && System.speed_accum_x100 == accum_before, what);
		}
	}
	fclose(f);

	printf("\nParsed %d lines without crashing.\n", total_lines);
	check(total_lines > 250, "fixture file actually has content");

	/* Section 3: the HDOP-16.2, 44.8 km/h sample must be excluded outright -
	 * the average right after it must still equal the ~4.3 km/h warm-up
	 * average, not be pulled up towards 44.8. */
	check(System.speed_sample_count >= 64, "warm-up samples were accepted");
	{
		double avg = (double)System.speed_accum_x100 / System.speed_sample_count / 100.0;
		char what[128];
		snprintf(what, sizeof what, "average (%.2f km/h) unaffected by the HDOP-16.2 44.8 km/h sample", avg);
		check(avg > 2.0 && avg < 6.0, what);
	}

	/* The 200 km/h, good-HDOP spike must be capped (added to the sum at
	 * something well below 200, per SPEED_SAMPLE_CAP_MULT/FLOOR), not
	 * excluded outright: a real fast segment (car/train) must still count. */
	{
		double avg_after = (double)System.speed_accum_x100 / System.speed_sample_count / 100.0;
		char what[160];
		snprintf(what, sizeof what, "200 km/h spike was capped, not excluded nor let through raw (average now %.2f km/h)", avg_after);
		check(avg_after > 2.5 && avg_after < 15.0, what);
	}

	if (failures) {
		printf("\n%d check(s) FAILED\n", failures);
		return 1;
	}
	printf("\nAll checks passed.\n");
	return 0;
}