1 files changed, 124 insertions, 0 deletions
diff --git a/jstests/core/geo_mindistance_boundaries.js b/jstests/core/geo_mindistance_boundaries.js
new file mode 100644
index 00000000000..80e933827b6
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+++ b/jstests/core/geo_mindistance_boundaries.js
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+/* Test boundary conditions for $minDistance option for $near and $nearSphere
+ * queries. SERVER-9395.
+*/
+var t = db.geo_mindistance_boundaries;
+t.drop();
+t.insert({loc: [1, 0]});  // 1 degree of longitude from origin.
+
+/* $minDistance is supported for 2dsphere index only, not 2d or geoHaystack. */
+t.ensureIndex({loc: "2dsphere"});
+
+//
+// Useful constants.
+//
+
+var km = 1000,
+    earthRadiusMeters = 6378.1 * km,
+    geoJSONPoint = {type: 'Point', coordinates: [0, 0]},
+    // One degree of longitude at the equator, about 111 km.
+    degreeInMeters = 2 * Math.PI * earthRadiusMeters / 360,
+    metersEpsilon = Number.MIN_VALUE;
+
+/* Grow epsilon's exponent until epsilon exceeds the margin of error for the
+ * representation of degreeInMeters. The server uses 64-bit math, too, so we'll
+ * find the smallest epsilon the server can detect.
+*/
+while (degreeInMeters + metersEpsilon == degreeInMeters) { metersEpsilon *= 2; }
+
+//
+// Test boundary conditions for $near and GeoJSON, in meters.
+//
+
+
+// minDistance must be within the args to $near, not on the side.
+assert.throws(function() { t.find({loc:{$near:{$geometry: geoJSONPoint},
+                                        $minDistance:0.1}}).itcount();});
+
+assert.eq(
+    1, t.find({loc: {
+        $near: {$geometry: geoJSONPoint,
+                $minDistance: degreeInMeters
+    }}}).itcount(),
+    "Expected to find (0, 1) within $minDistance 1 degree from origin"
+);
+
+assert.eq(
+    1, t.find({loc: {
+        $near: {$geometry: geoJSONPoint,
+                $minDistance: degreeInMeters - metersEpsilon
+    }}}).itcount(),
+    "Expected to find (0, 1) within $minDistance (1 degree - epsilon) from origin"
+);
+
+assert.eq(
+    0, t.find({loc: {
+        $near: {$geometry: geoJSONPoint,
+                $minDistance: degreeInMeters + metersEpsilon
+    }}}).itcount(),
+    "Expected *not* to find (0, 1) within $minDistance (1 degree + epsilon) from origin"
+);
+
+//
+// Test boundary conditions for $nearSphere and GeoJSON, in meters.
+//
+
+assert.eq(
+    1, t.find({loc: {
+        $nearSphere: {$geometry: geoJSONPoint,
+                      $minDistance: degreeInMeters
+    }}}).itcount(),
+    "Expected to find (0, 1) within $minDistance 1 degree from origin"
+);
+
+assert.eq(
+    1, t.find({loc: {
+        $nearSphere: geoJSONPoint,
+        $minDistance: degreeInMeters - metersEpsilon
+    }}).itcount(),
+    "Expected to find (0, 1) within $minDistance (1 degree - epsilon) from origin"
+);
+
+assert.eq(
+    0, t.find({loc: {
+        $nearSphere: geoJSONPoint,
+        $minDistance: degreeInMeters + metersEpsilon
+    }}).itcount(),
+    "Expected *not* to find (0, 1) within $minDistance (1 degree + epsilon) from origin"
+);
+
+//
+// Test boundary conditions for $nearSphere and a legacy point, in radians.
+//
+// $minDistance with legacy point requires $nearSphere; $near not
+// supported.
+//
+
+var legacyPoint = [0, 0],
+    degreeInRadians = 2 * Math.PI / 360,
+    radiansEpsilon = Number.MIN_VALUE;
+
+while (1 + radiansEpsilon == 1) { radiansEpsilon *= 2; }
+
+assert.eq(
+    1, t.find({loc: {
+        $nearSphere: legacyPoint,
+        $minDistance: degreeInRadians
+    }}).itcount(),
+    "Expected to find (0, 1) within $minDistance 1 degree from origin"
+);
+
+assert.eq(
+    1, t.find({loc: {
+        $nearSphere: legacyPoint,
+        $minDistance: degreeInRadians - radiansEpsilon
+    }}).itcount(),
+    "Expected to find (0, 1) within $minDistance (1 degree - epsilon) from origin"
+);
+
+assert.eq(
+    0, t.find({loc: {
+        $nearSphere: legacyPoint,
+        $minDistance: degreeInRadians + radiansEpsilon
+    }}).itcount(),
+    "Expected *not* to find (0, 1) within $minDistance (1 degree + epsilon) from origin"
+);