GPS: do not report a fix whose position is outside +-90/+-180 degrees

.github/workflows/run-unit-tests.yml

@@ -20,7 +20,7 @@ jobs:
         uses: ./.github/actions/setup-build-environment
 
       - name: Run Unit Tests
-        run: pio test -e native -e native_kiss_modem -vv
+        run: pio test -e native -e native_kiss_modem -e native_gps -vv
 
       - name: Upload Test Results
         # Upload test results even if the test step failed.

platformio.ini

@@ -167,7 +167,7 @@ build_flags = -std=c++17
   -I src
   -I test/mocks
 test_build_src = yes
-test_ignore = test_kiss_modem
+test_ignore = test_kiss_modem, test_gps_nmea
 build_src_filter =
   -<*>
   +<../src/Utils.cpp>
@@ -191,3 +191,26 @@ build_src_filter =
   +<../examples/kiss_modem/KissModem.cpp>
 lib_deps =
   google/googletest @ 1.17.0
+
+; GPS/NMEA provider tests compile the real provider header against the real
+; MicroNMEA library. The mocks must shadow src/ (same ordering as the KISS
+; modem suite). MicroNMEA is an Arduino-format library, so compatibility
+; checks are off to let it build for the native platform. Sanitizers make
+; out-of-bounds reads in the parser fail the test instead of passing silently.
+[env:native_gps]
+platform = native
+test_framework = googletest
+build_flags = -std=c++17
+  -I test/mocks
+  -I src
+  -fsanitize=address,undefined
+  -fno-sanitize-recover=all
+  -fno-omit-frame-pointer
+test_build_src = yes
+test_filter = test_gps_nmea
+build_src_filter =
+  -<*>
+lib_compat_mode = off
+lib_deps =
+  google/googletest @ 1.17.0
+  stevemarple/MicroNMEA @ 2.0.6

src/helpers/sensors/MicroNMEALocationProvider.h

@@ -166,7 +166,16 @@ public :
         return alt;
     }
     long satellitesCount() override { return nmea.getNumSatellites(); }
-    bool isValid() override { return nmea.isValid(); }
+    bool isValid() override {
+        // MicroNMEA can report a fix whose position fields did not parse, for
+        // example a checksum-valid sentence with a field missing. Do not call
+        // a position no receiver can report a fix.
+        if (!nmea.isValid()) return false;
+        const long lat = nmea.getLatitude();
+        const long lon = nmea.getLongitude();
+        return lat >= -90000000L && lat <= 90000000L
+            && lon >= -180000000L && lon <= 180000000L;
+    }
 
     long getTimestamp() override { 
         DateTime dt(nmea.getYear(), nmea.getMonth(),nmea.getDay(),nmea.getHour(),nmea.getMinute(),nmea.getSecond());

test/mocks/Arduino.h

@@ -2,6 +2,7 @@
 
 #include <cstdint>
 #include <cmath>
+#include <ctype.h>  // Arduino.h provides the C character classification functions
 #include "Stream.h"
 
 inline uint32_t g_mock_millis = 0;
@@ -15,3 +16,26 @@ inline uint32_t millis() {
 inline void delay(uint32_t ms) {
   g_mock_millis += ms;
 }
+
+// Busy-wait loops call yield(); let mock time move so they can time out.
+inline void yield() {
+  g_mock_millis += 1;
+}
+
+// Minimal digital I/O so headers that drive enable/reset pins compile natively.
+constexpr uint8_t LOW = 0;
+constexpr uint8_t HIGH = 1;
+constexpr uint8_t INPUT = 0;
+constexpr uint8_t OUTPUT = 1;
+
+inline uint8_t g_mock_pin_levels[64] = {};
+
+inline void pinMode(uint8_t, uint8_t) {}
+
+inline void digitalWrite(uint8_t pin, uint8_t level) {
+  if (pin < 64) g_mock_pin_levels[pin] = level;
+}
+
+inline int digitalRead(uint8_t pin) {
+  return pin < 64 ? g_mock_pin_levels[pin] : LOW;
+}

test/mocks/Mesh.h

@@ -15,6 +15,13 @@ class Radio {
   virtual int16_t getNoiseFloor() { return -120; }
 };
 
+class RTCClock {
+public:
+  virtual ~RTCClock() = default;
+  virtual uint32_t getCurrentTime() = 0;
+  virtual void setCurrentTime(uint32_t time) = 0;
+};
+
 class MainBoard {
 public:
   virtual ~MainBoard() = default;

test/mocks/RTClib.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <stdint.h>
+
+// Minimal DateTime stand-in for native tests. unixtime() matches RTClib for
+// valid dates from 2000 to 2099, the range RTClib supports (seconds since
+// 1970-01-01 UTC). Out-of-range fields map to a deterministic value instead of
+// indexing past the month table, so tests can compare two parses of the same
+// bytes; such values are not what RTClib would return.
+class DateTime {
+  uint16_t _year;
+  uint8_t _month, _day, _hour, _minute, _second;
+
+  static bool leap(uint16_t year) {
+    return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
+  }
+
+public:
+  DateTime(uint16_t year, uint8_t month, uint8_t day, uint8_t hour,
+           uint8_t minute, uint8_t second)
+      : _year(year), _month(month), _day(day), _hour(hour),
+        _minute(minute), _second(second) {}
+
+  uint32_t unixtime() const {
+    uint32_t days = 0;
+    for (uint16_t year = 1970; year < _year; ++year)
+      days += leap(year) ? 366 : 365;
+    if (_month >= 1 && _month <= 12) {
+      const uint8_t month_days[] = {31, 28, 31, 30, 31, 30,
+                                    31, 31, 30, 31, 30, 31};
+      for (uint8_t month = 1; month < _month; ++month)
+        days += month_days[month - 1] + (month == 2 && leap(_year) ? 1 : 0);
+      days += _day - 1;
+    } else {
+      days += 31UL * _month + _day;  // deterministic, not calendar-correct
+    }
+    return days * 86400UL + _hour * 3600UL + _minute * 60UL + _second;
+  }
+};

test/test_gps_nmea/gps_test_support.h

@@ -0,0 +1,49 @@
+#pragma once
+
+// Shared helpers for the native GPS/NMEA tests: the real
+// MicroNMEALocationProvider and MicroNMEA, fed through a mock UART.
+
+#include <gtest/gtest.h>
+
+#include <MicroNMEA.h>
+#include <helpers/sensors/MicroNMEALocationProvider.h>
+
+#include <cstdio>
+#include <cstring>
+#include <deque>
+#include <string>
+
+
+struct MockSerial : Stream {
+  std::deque<char> queue;
+  int available() override { return (int)queue.size(); }
+  int read() override {
+    if (queue.empty()) return -1;
+    char c = queue.front();
+    queue.pop_front();
+    return (unsigned char)c;
+  }
+  void feed(const std::string& text) {
+    for (char c : text) queue.push_back(c);
+  }
+};
+
+// "$" + body + "*" + two hex digits, the checksum MicroNMEA expects.
+inline std::string withChecksum(const std::string& body) {
+  uint8_t sum = 0;
+  for (char c : body) sum ^= (uint8_t)c;
+  char hex[4];
+  snprintf(hex, sizeof(hex), "%02X", sum);
+  return "$" + body + "*" + hex;
+}
+
+inline void feedAndLoop(MicroNMEALocationProvider& gps, MockSerial& serial,
+                 const std::string& line) {
+  serial.feed(line + "\r\n");
+  gps.loop();
+}
+
+inline constexpr const char* kGoodRmc =
+    "GPRMC,120034.00,A,4716.1234,N,12233.5678,W,0.12,34.5,171026,003.1,W,A";
+inline constexpr const char* kGoodGga =
+    "GPGGA,120034.00,4716.1234,N,12233.5678,W,1,08,0.9,125.0,M,-17.0,M,,";

test/test_gps_nmea/test_coordinate_range.cpp

@@ -0,0 +1,91 @@
+#include "gps_test_support.h"
+
+namespace {
+
+// RMC with the given latitude/longitude fields and status, valid checksum.
+std::string rmcAt(const char* lat, const char* ns, const char* lon,
+                  const char* ew, const char* status = "A") {
+  return withChecksum(std::string("GPRMC,120034.00,") + status + "," + lat + "," +
+                      ns + "," + lon + "," + ew + ",0.12,34.5,171026,003.1,W,A");
+}
+
+struct Fix {
+  bool valid;
+  long lat;
+  long lon;
+};
+
+Fix parseWithProvider(const std::string& sentence) {
+  MockSerial serial;
+  MicroNMEALocationProvider gps(serial, nullptr, -1, -1);
+  feedAndLoop(gps, serial, sentence);
+  return {gps.isValid(), gps.getLatitude(), gps.getLongitude()};
+}
+
+bool libraryCallsItAFix(const std::string& sentence) {
+  char buffer[100] = {};
+  MicroNMEA nmea(buffer, sizeof(buffer));
+  for (char c : sentence) nmea.process(c);
+  nmea.process('\n');
+  return nmea.isValid();
+}
+
+}  // namespace
+
+TEST(MicroNMEAProviderRange, RealFixesUpToTheBoundariesAreValid) {
+  const struct { const char *lat, *ns, *lon, *ew; long want_lat, want_lon; } cases[] = {
+      {"4716.1234", "N", "12233.5678", "W", 47268723L, -122559463L},
+      {"9000.0000", "N", "18000.0000", "E", 90000000L, 180000000L},
+      {"9000.0000", "S", "18000.0000", "W", -90000000L, -180000000L},
+      {"0000.0000", "N", "00000.0000", "E", 0L, 0L},
+  };
+  for (const auto& c : cases) {
+    SCOPED_TRACE(std::string(c.lat) + c.ns + " " + c.lon + c.ew);
+    const Fix fix = parseWithProvider(rmcAt(c.lat, c.ns, c.lon, c.ew));
+    EXPECT_TRUE(fix.valid);
+    EXPECT_EQ(c.want_lat, fix.lat);
+    EXPECT_EQ(c.want_lon, fix.lon);
+  }
+}
+
+TEST(MicroNMEAProviderRange, PositionsNoReceiverCanReportAreNotAFix) {
+  const struct { const char *lat, *ns, *lon, *ew; } cases[] = {
+      {"9000.0010", "N", "12233.5678", "W"},   // 90.0000166 N
+      {"9000.0010", "S", "12233.5678", "W"},   // 90.0000166 S
+      {"9930.0000", "N", "12233.5678", "W"},   // 99.5 N, inside +-180
+      {"4716.1234", "N", "18000.0010", "E"},   // 180.0000166 E
+      {"4716.1234", "N", "18000.0010", "W"},   // 180.0000166 W
+      {"4716.1234", "N", "18500.0000", "W"},   // 185 W
+  };
+  for (const auto& c : cases) {
+    const std::string sentence = rmcAt(c.lat, c.ns, c.lon, c.ew);
+    SCOPED_TRACE(sentence);
+    ASSERT_TRUE(libraryCallsItAFix(sentence));
+    EXPECT_FALSE(parseWithProvider(sentence).valid);
+  }
+}
+
+TEST(MicroNMEAProviderRange, ChecksumValidSentenceWithAMissingFieldIsNotAFix) {
+  // The N/S field is missing. The library skips two characters of the
+  // longitude instead and reads "233.5678" as degrees and minutes: 233 deg.
+  const std::string sentence = withChecksum(
+      "GPRMC,120034.00,A,4716.1234,12233.5678,W,0.12,34.5,171026,003.1,W,A");
+  ASSERT_TRUE(libraryCallsItAFix(sentence));
+  const Fix fix = parseWithProvider(sentence);
+  EXPECT_GT(fix.lon < 0 ? -fix.lon : fix.lon, 180000000L);
+  EXPECT_FALSE(fix.valid);
+}
+
+TEST(MicroNMEAProviderRange, NoFixIsStillNoFix) {
+  EXPECT_FALSE(parseWithProvider(rmcAt("4716.1234", "N", "12233.5678", "W", "V")).valid);
+}
+
+TEST(MicroNMEAProviderRange, GgaPositionIsCheckedToo) {
+  const std::string good = withChecksum(
+      "GPGGA,120034.00,4716.1234,N,12233.5678,W,1,08,0.9,125.0,M,-17.0,M,,");
+  const std::string bad = withChecksum(
+      "GPGGA,120034.00,9930.0000,N,12233.5678,W,1,08,0.9,125.0,M,-17.0,M,,");
+  EXPECT_TRUE(parseWithProvider(good).valid);
+  ASSERT_TRUE(libraryCallsItAFix(bad));
+  EXPECT_FALSE(parseWithProvider(bad).valid);
+}

test/test_gps_nmea/test_main.cpp

@@ -0,0 +1,9 @@
+#include "gps_test_support.h"
+
+// Defined in EnvironmentSensorManager.cpp, which is not part of this build.
+void LocationProvider::sendSentence(const char*) {}
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

test/test_gps_nmea/test_parsing.cpp

@@ -0,0 +1,30 @@
+#include "gps_test_support.h"
+
+TEST(MicroNMEAProvider, ParsesWellFormedSentences) {
+  g_mock_millis = 1000;
+  MockSerial serial;
+  MicroNMEALocationProvider gps(serial, nullptr, -1, -1);
+  feedAndLoop(gps, serial, withChecksum(kGoodGga));
+  feedAndLoop(gps, serial, withChecksum(kGoodRmc));
+
+  EXPECT_TRUE(gps.isValid());
+  EXPECT_EQ(47268723L, gps.getLatitude());     // 47 deg 16.1234' N
+  EXPECT_EQ(-122559463L, gps.getLongitude());  // 122 deg 33.5678' W
+  EXPECT_EQ(8L, gps.satellitesCount());
+  EXPECT_EQ(125000L, gps.getAltitude());
+  EXPECT_EQ(1792238434L, gps.getTimestamp());  // 2026-10-17 12:00:34 UTC
+}
+
+TEST(MicroNMEAProvider, LongestSentenceTheBufferHoldsStillParses) {
+  std::string body = kGoodRmc;
+  while (body.size() < 99 - 4) body.push_back('Z');  // pad the final field
+  const std::string sentence = withChecksum(body);
+  ASSERT_EQ(99u, sentence.size());
+
+  g_mock_millis = 1000;
+  MockSerial serial;
+  MicroNMEALocationProvider gps(serial, nullptr, -1, -1);
+  feedAndLoop(gps, serial, sentence);
+  EXPECT_TRUE(gps.isValid());
+  EXPECT_EQ(47268723L, gps.getLatitude());
+}