Support for querying by guid

Author: borigas

src/CouchDB.Driver/Translators/ConstantExpressionTranslator.cs

@@ -41,14 +41,16 @@ protected override Expression VisitConstant(ConstantExpression c)
                             VisitIEnumerable(c.Value as IList<int>);
                         else if (c.Value is IList<long>)
                             VisitIEnumerable(c.Value as IList<long>);
-                        else if(c.Value is IList<decimal>)
+                        else if (c.Value is IList<decimal>)
                             VisitIEnumerable(c.Value as IList<decimal>);
                         else if (c.Value is IList<float>)
                             VisitIEnumerable(c.Value as IList<float>);
                         else if (c.Value is IList<double>)
                             VisitIEnumerable(c.Value as IList<double>);
-                        else if(c.Value is IList<string>)
+                        else if (c.Value is IList<string>)
                             VisitIEnumerable(c.Value as IList<string>);
+                        else if (c.Value is Guid)
+                            _sb.Append(JsonConvert.SerializeObject(c.Value));
                         else
                             throw new NotSupportedException(string.Format("The constant for '{0}' is not supported", c.Value));
                         break;
@@ -85,7 +87,7 @@ string VisitConst(object o)
                     case TypeCode.String:
                         return $"\"{o}\"";
                     case TypeCode.Object:
-                        throw new NotSupportedException(string.Format("The constant for '{0}' is not supported", o));                        
+                        throw new NotSupportedException(string.Format("The constant for '{0}' is not supported", o));
                     default:
                         return o.ToString();
                 }

tests/CouchDB.Driver.UnitTests/Find/Find_Selector.cs

@@ -24,9 +24,9 @@ public void ToList_EmptySelector()
         [Fact]
         public void ComplexQuery()
         {
-            var json = rebels.Where(r => 
-            r.Age == 19 && 
-            (r.Name == "Luke" || r.Name == "Leia") && 
+            var json = rebels.Where(r =>
+            r.Age == 19 &&
+            (r.Name == "Luke" || r.Name == "Leia") &&
             r.Skills.Contains("force")).ToString();
             Assert.Equal(@"{""selector"":{""$and"":[{""age"":19},{""$or"":[{""name"":""Luke""},{""name"":""Leia""}]},{""skills"":{""$all"":[""force""]}}]}}", json);
         }
@@ -65,5 +65,13 @@ public void Enum()
             var json = rebels.Where(r => r.Species == Species.Human).ToString();
             Assert.Equal(@"{""selector"":{""species"":0}}", json);
         }
+        [Fact]
+        public void GuidQuery()
+        {
+            var guidString = "83c79283-f634-41e3-8aab-674bdbae3413";
+            var guid = Guid.Parse(guidString);
+            var json = rebels.Where(r => r.Guid == guid).ToString();
+            Assert.Equal(@"{""selector"":{""guid"":""83c79283-f634-41e3-8aab-674bdbae3413""}}", json);
+        }
     }
 }

tests/CouchDB.Driver.UnitTests/_Models/Rebel.cs

@@ -11,6 +11,7 @@ public class Rebel : CouchDocument
         public string Surname { get; set; }
         public int Age { get; set; }
         public Species Species { get; set; }
+        public Guid Guid { get; set; }
         public List<string> Skills { get; set; }
         public List<Battle> Battles { get; set; }
     }