From 673046900ad0eabaa65bcd66c508047ce24af806 Mon Sep 17 00:00:00 2001
From: Isaac Brodsky <isaac@isaacbrodsky.com>
Date: Sun, 28 Jan 2024 11:07:49 -0800
Subject: [PATCH] add fuzzer derived test case

---
 .../testapps/testPolygonToCellsExperimental.c | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/src/apps/testapps/testPolygonToCellsExperimental.c b/src/apps/testapps/testPolygonToCellsExperimental.c
index 988880e95..0710f54ed 100644
--- a/src/apps/testapps/testPolygonToCellsExperimental.c
+++ b/src/apps/testapps/testPolygonToCellsExperimental.c
@@ -49,6 +49,12 @@ static GeoPolygon emptyGeoPolygon;
 static GeoLoop nullGeoLoop = {.numVerts = 0};
 static GeoPolygon nullGeoPolygon;
 
+static LatLng singleVert[] = {
+    {-2458342481021883972259660398208400791736363001944288341450980211606536535492675816838520454729626606617401537208948885147545930079455247090683734597891092223711178354749340595418656865312221132096067702544124896034621453367423118181128977366942366333665280.000000,
+     -2458343740331028994843467164510968055426643495662759512417906485158670133931720348722610840257947672725818463095310525347561848316357826117675135273725409046652087471434926446163500402816566116551621419239229327985229318738203409398420671266791854901821440.000000}};
+static GeoLoop singleVertGeoLoop = {.numVerts = 1, .verts = singleVert};
+static GeoPolygon singleVertGeoPolygon;
+
 static GeoPolygon sfGeoPolygonWithNullHole;
 
 static LatLng invalidVerts[] = {{INFINITY, INFINITY}, {-INFINITY, -INFINITY}};
@@ -155,6 +161,9 @@ SUITE(polygonToCells) {
     nullGeoPolygon.geoloop = nullGeoLoop;
     nullGeoPolygon.numHoles = 0;
 
+    singleVertGeoPolygon.geoloop = singleVertGeoLoop;
+    singleVertGeoPolygon.numHoles = 0;
+
     sfGeoPolygonWithNullHole.geoloop = sfGeoLoop;
     sfGeoPolygonWithNullHole.numHoles = 1;
     sfGeoPolygonWithNullHole.holes = &nullGeoLoop;
@@ -366,6 +375,26 @@ SUITE(polygonToCells) {
         }
     }
 
+    TEST(polygonToCellsSingleVert) {
+        for (int res = 0; res < MAX_H3_RES; res++) {
+            for (uint32_t flags = 0; flags < CONTAINMENT_INVALID; flags++) {
+                int64_t numHexagons;
+                t_assertSuccess(H3_EXPORT(maxPolygonToCellsSizeExperimental)(
+                    &singleVertGeoPolygon, res, flags, &numHexagons));
+                H3Index *hexagons = calloc(numHexagons, sizeof(H3Index));
+
+                t_assertSuccess(H3_EXPORT(polygonToCellsExperimental)(
+                    &singleVertGeoPolygon, res, flags, hexagons));
+                int64_t actualNumIndexes =
+                    countNonNullIndexes(hexagons, numHexagons);
+
+                t_assert(actualNumIndexes == 0,
+                         "got expected polygonToCells size (null)");
+                free(hexagons);
+            }
+        }
+    }
+
     TEST(polygonToCellsContainsPolygon) {
         int64_t numHexagons;
         t_assertSuccess(H3_EXPORT(maxPolygonToCellsSizeExperimental)(