SERVER-393 SERVER-2902 additional tests

jstests/exists9.js

@@ -0,0 +1,44 @@
+// SERVER-393 Test exists with various empty array and empty object cases.
+
+t = db.jstests_exists9;
+t.drop();
+
+// Check existence of missing nested field.
+t.save( {a:{}} );
+assert.eq( 1, t.count( {'a.b':{$exists:false}} ) );
+assert.eq( 0, t.count( {'a.b':{$exists:true}} ) );
+
+// With index.
+t.ensureIndex( {'a.b':1} );
+assert.eq( 1, t.find( {'a.b':{$exists:false}} ).hint( {'a.b':1} ).itcount() );
+assert.eq( 0, t.find( {'a.b':{$exists:true}} ).hint( {'a.b':1} ).itcount() );
+
+t.drop();
+
+// Check that an empty array 'exists'.
+t.save( {} );
+t.save( {a:[]} );
+assert.eq( 1, t.count( {a:{$exists:true}} ) );
+assert.eq( 1, t.count( {a:{$exists:false}} ) );
+
+// With index.
+t.ensureIndex( {a:1} );
+assert.eq( 1, t.find( {a:{$exists:true}} ).hint( {a:1} ).itcount() );
+assert.eq( 1, t.find( {a:{$exists:false}} ).hint( {a:1} ).itcount() );
+// The empty array will be scanned, but not returned.
+assert.eq( 2, t.find( {a:{$exists:false}} ).hint( {a:1} ).explain().nscanned );
+
+t.drop();
+
+// Check that an indexed field within an empty array does not exist.
+t.save( {a:{'0':1}} );
+t.save( {a:[]} );
+assert.eq( 1, t.count( {'a.0':{$exists:true}} ) );
+assert.eq( 1, t.count( {'a.0':{$exists:false}} ) );
+
+// With index.
+t.ensureIndex( {'a.0':1} );
+assert.eq( 1, t.find( {'a.0':{$exists:true}} ).hint( {'a.0':1} ).itcount() );
+if ( 0 ) { // SERVER-2902
+assert.eq( 1, t.find( {'a.0':{$exists:false}} ).hint( {'a.0':1} ).itcount() );
+}