datastore: Expose entity identification functions. (#2645)

packages/datastore/src/entity.js

@@ -59,6 +59,18 @@ function Double(value) {
 
 entity.Double = Double;
 
+/**
+ * Check if something is a Datastore Double object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ */
+function isDsDouble(value) {
+  return value instanceof entity.Double;
+}
+
+entity.isDsDouble = isDsDouble;
+
 /**
  * Build a Datastore Int object. For long integers, a string can be provided.
  *
@@ -74,6 +86,18 @@ function Int(value) {
 
 entity.Int = Int;
 
+/**
+ * Check if something is a Datastore Int object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ */
+function isDsInt(value) {
+  return value instanceof entity.Int;
+}
+
+entity.isDsInt = isDsInt;
+
 /**
  * Build a Datastore Geo Point object.
  *
@@ -90,12 +114,24 @@ entity.Int = Int;
  *
  * var geoPoint = new GeoPoint(coordinates);
  */
-function GeoPoint(coordindates) {
-  this.value = coordindates;
+function GeoPoint(coordinates) {
+  this.value = coordinates;
 }
 
 entity.GeoPoint = GeoPoint;
 
+/**
+ * Check if something is a Datastore Geo Point object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ */
+function isDsGeoPoint(value) {
+  return value instanceof entity.GeoPoint;
+}
+
+entity.isDsGeoPoint = isDsGeoPoint;
+
 /**
  * Build a Datastore Key object.
  *
@@ -116,7 +152,7 @@ function Key(options) {
   if (options.path.length % 2 === 0) {
     var identifier = options.path.pop();
 
-    if (is.number(identifier) || identifier instanceof entity.Int) {
+    if (is.number(identifier) || isDsInt(identifier)) {
       this.id = identifier.value || identifier;
     } else if (is.string(identifier)) {
       this.name = identifier;
@@ -142,6 +178,18 @@ function Key(options) {
 
 entity.Key = Key;
 
+/**
+ * Check if something is a Datastore Key object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ */
+function isDsKey(value) {
+  return value instanceof entity.Key;
+}
+
+entity.isDsKey = isDsKey;
+
 /**
  * Convert a protobuf Value message to its native value.
  *
@@ -243,17 +291,17 @@ function encodeValue(value) {
     }
   }
 
-  if (value instanceof entity.Int) {
+  if (isDsInt(value)) {
     valueProto.integerValue = value.value;
     return valueProto;
   }
 
-  if (value instanceof entity.Double) {
+  if (isDsDouble(value)) {
     valueProto.doubleValue = value.value;
     return valueProto;
   }
 
-  if (value instanceof entity.GeoPoint) {
+  if (isDsGeoPoint(value)) {
     valueProto.geoPointValue = value.value;
     return valueProto;
   }
@@ -286,7 +334,7 @@ function encodeValue(value) {
     return valueProto;
   }
 
-  if (value instanceof entity.Key) {
+  if (isDsKey(value)) {
     valueProto.keyValue = entity.keyToKeyProto(value);
     return valueProto;
   }

packages/datastore/src/index.js

@@ -343,6 +343,20 @@ Datastore.prototype.double = Datastore.double = function(value) {
   return new entity.Double(value);
 };
 
+/**
+ * Helper function to check if something is a Datastore Double object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ *
+ * @example
+ * datastore.isDouble(0.42); // false
+ * datastore.isDouble(datastore.double(0.42)); // true
+ */
+Datastore.prototype.isDouble = Datastore.isDouble = function(value) {
+  return entity.isDsDouble(value);
+};
+
 /**
  * Helper function to get a Datastore Geo Point object.
  *
@@ -359,8 +373,27 @@ Datastore.prototype.double = Datastore.double = function(value) {
  *
  * var geoPoint = datastore.geoPoint(coordinates);
  */
-Datastore.prototype.geoPoint = Datastore.geoPoint = function(coordindates) {
-  return new entity.GeoPoint(coordindates);
+Datastore.prototype.geoPoint = Datastore.geoPoint = function(coordinates) {
+  return new entity.GeoPoint(coordinates);
+};
+
+/**
+ * Helper function to check if something is a Datastore Geo Point object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ *
+ * @example
+ * var coordinates = {
+ *   latitude: 0,
+ *   longitude: 0
+ * };
+ *
+ * datastore.isGeoPoint(coordinates); // false
+ * datastore.isGeoPoint(datastore.geoPoint(coordinates)); // true
+ */
+Datastore.prototype.isGeoPoint = Datastore.isGeoPoint = function(value) {
+  return entity.isDsGeoPoint(value);
 };
 
 /**
@@ -387,6 +420,20 @@ Datastore.prototype.int = Datastore.int = function(value) {
   return new entity.Int(value);
 };
 
+/**
+ * Helper function to check if something is a Datastore Integer object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ *
+ * @example
+ * datastore.isInt(42); // false
+ * datastore.isInt(datastore.int(42)); // true
+ */
+Datastore.prototype.isInt = Datastore.isInt = function(value) {
+  return entity.isDsInt(value);
+};
+
 /**
  * Access the Key from an Entity object.
  *
@@ -509,6 +556,20 @@ Datastore.prototype.key = function(options) {
   return new entity.Key(options);
 };
 
+/**
+ * Helper function to check if something is a Datastore Key object.
+ *
+ * @param {*} value
+ * @return {boolean}
+ *
+ * @example
+ * datastore.isKey({path: ['Company', 123]}); // false
+ * datastore.isKey(datastore.key(['Company', 123])); // true
+ */
+Datastore.prototype.isKey = Datastore.isKey = function(value) {
+  return entity.isDsKey(value);
+};
+
 /**
  * Create a new Transaction object.
  *

packages/datastore/test/entity.js

@@ -48,6 +48,23 @@ describe('entity', function() {
     });
   });
 
+  describe('isDsDouble', function() {
+    it('should correctly identify a Double', function() {
+      var double = new entity.Double(0.42);
+      assert.strictEqual(entity.isDsDouble(double), true);
+    });
+
+    it('should correctly identify a homomorphic non-Double', function() {
+      var nonDouble = Object.assign({}, new entity.Double(42));
+      assert.strictEqual(entity.isDsDouble(nonDouble), false);
+    });
+
+    it('should correctly identify a primitive', function() {
+      var primitiveDouble = 0.42;
+      assert.strictEqual(entity.isDsDouble(primitiveDouble), false);
+    });
+  });
+
   describe('Int', function() {
     it('should store the stringified value', function() {
       var value = 8;
@@ -57,6 +74,23 @@ describe('entity', function() {
     });
   });
 
+  describe('isDsInt', function() {
+    it('should correctly identify an Int', function() {
+      var int = new entity.Int(42);
+      assert.strictEqual(entity.isDsInt(int), true);
+    });
+
+    it('should correctly identify homomorphic non-Int', function() {
+      var nonInt = Object.assign({}, new entity.Int(42));
+      assert.strictEqual(entity.isDsInt(nonInt), false);
+    });
+
+    it('should correctly identify a primitive', function() {
+      var primitiveInt = 42;
+      assert.strictEqual(entity.isDsInt(primitiveInt), false);
+    });
+  });
+
   describe('GeoPoint', function() {
     it('should store the value', function() {
       var value = {
@@ -69,6 +103,19 @@ describe('entity', function() {
     });
   });
 
+  describe('isDsGeoPoint', function() {
+    it('should correctly identify a GeoPoint', function() {
+      var geoPoint = new entity.GeoPoint({latitude: 24, longitude: 88});
+      assert.strictEqual(entity.isDsGeoPoint(geoPoint), true);
+    });
+
+    it('should correctly identify a homomorphic non-GeoPoint', function() {
+      var geoPoint = new entity.GeoPoint({latitude: 24, longitude: 88});
+      var nonGeoPoint = Object.assign({}, geoPoint);
+      assert.strictEqual(entity.isDsGeoPoint(nonGeoPoint), false);
+    });
+  });
+
   describe('Key', function() {
     it('should assign the namespace', function() {
       var namespace = 'NS';
@@ -116,6 +163,18 @@ describe('entity', function() {
     });
   });
 
+  describe('isDsKey', function() {
+    it('should correctly identify a Key', function() {
+      var key = new entity.Key({path: ['Kind', 1]});
+      assert.strictEqual(entity.isDsKey(key), true);
+    });
+
+    it('should correctly identify a homomorphic non-Key', function() {
+      var notKey = Object.assign({}, new entity.Key({path: ['Kind', 1]}));
+      assert.strictEqual(entity.isDsKey(notKey), false);
+    });
+  });
+
   describe('decodeValueProto', function() {
     it('should decode arrays', function() {
       var expectedValue = [{}];