Feat(GraphQL): This PR adds parameterised cascade in graphql.

graphql/dgraph/graphquery.go

@@ -72,6 +72,10 @@ func writeQuery(b *strings.Builder, query *gql.GraphQuery, prefix string) {
 	if len(query.Cascade) != 0 {
 		if query.Cascade[0] == "__all__" {
 			x.Check2(b.WriteString(" @cascade"))
+		} else {
+			x.Check2(b.WriteString(" @cascade("))
+			x.Check2(b.WriteString(strings.Join(query.Cascade,",")))
+			x.Check2(b.WriteRune(')'))
 		}
 	}
 

graphql/e2e/common/error_test.yaml

@@ -89,7 +89,7 @@
     [ { "message": "must be defined",
       "path": [ "variable", "filter"] } ]
 -
-  name: "subscription on type without @withSubscription directive should retur error"
+  name: "subscription on type without @withSubscription directive should return error"
   gqlrequest: |
     subscription {
       getAuthor(id: "0x1") { name }
@@ -100,3 +100,17 @@
     [ { "message": "Cannot query field \"getAuthor\" on type \"Subscription\".",
         "locations": [ { "line": 2, "column": 3 } ] } ]
 
+-
+  name: "@cascade only accepts those fields as a argument, which are present in given type "
+  gqlrequest: |
+    query {
+      queryAuthor @cascade(fields:["title"]){
+        dob
+        reputation
+      }
+    }
+  gqlvariables:
+    { }
+  errors:
+    [ { "message": "Field `title` is not present in type `Author`. You can only use fields which are in type `Author`",
+    } ]

graphql/e2e/common/query.go

@@ -1697,15 +1697,18 @@ func queryWithCascade(t *testing.T) {
 		}, {
 			Name:       "Jerry",
 			Reputation: 4.6,
+			Country:&country{Name:"outer Galaxy2"},
 			Posts:      []*post{{Title: "Outside", Tags: []string{}}},
 		}, {
 			Name:  "Kramer",
+			Country:&country{Name:"outer space2"},
 			Posts: []*post{{Title: "Ha! Cosmo Kramer", Text: "Giddy up!", Tags: []string{}}},
 		},
 	}, postExecutor)
 	authorIds := []string{authors[0].ID, authors[1].ID, authors[2].ID}
 	postIds := []string{authors[0].Posts[0].PostID, authors[1].Posts[0].PostID,
 		authors[2].Posts[0].PostID}
+	countryIds:=[]string{authors[1].Country.ID,authors[2].Country.ID}
 	getAuthorByIdQuery := `query ($id: ID!) {
 							  getAuthor(id: $id) @cascade {
 								reputation
@@ -1826,6 +1829,108 @@ func queryWithCascade(t *testing.T) {
 							}]
 						}`,
 		},
+		{
+			name: "parameterized cascade with argument at outer level only",
+			query: `query ($ids: [ID!]) {
+					  queryAuthor(filter: {id: $ids})  @cascade(fields:["name"]) {
+						reputation
+                        name
+						country {
+                          name
+						}
+					  }
+					}`,
+			variables: map[string]interface{}{"ids": authorIds},
+			respData: `{
+							"queryAuthor": [{
+								"reputation": 4.6,
+								 "name":"Jerry",
+								 "country": {
+									"name": "outer Galaxy2"
+								   }
+                                 },
+                                 {
+								 "name":"Kramer",
+                                 "reputation": null,
+								 "country": {
+									"name": "outer space2"
+								   }
+                                 },
+                               { 
+								"reputation": 4.5,
+								 "name":"George",
+								 "country": null
+							}]
+						}`,
+		},
+		{
+			name: "parameterized cascade only at inner level ",
+			query: `query ($ids: [ID!]) {
+					  queryAuthor(filter: {id: $ids})  {
+						reputation
+                        name
+						posts @cascade(fields:["text"]) {
+						  title
+						  text
+						}
+					  }
+					}`,
+			variables: map[string]interface{}{"ids": authorIds},
+			respData: `{
+							"queryAuthor": [{
+								"reputation": 4.5,
+								 "name":"George",
+								"posts": [{
+									"title": "A show about nothing",
+									"text": "Got ya!"
+								}]
+							},
+                            {
+                                "name":"Kramer",
+                                "reputation": null,
+								"posts": [{
+									"title": "Ha! Cosmo Kramer",
+									"text": "Giddy up!"
+								}]
+							},
+                            {
+                                "name":"Jerry",
+								"reputation": 4.6,	
+								"posts": []
+                            }]
+						}`,
+		},
+		{
+			name: "parameterized cascade at all levels ",
+			query: `query ($ids: [ID!]) {
+					  queryAuthor(filter: {id: $ids}) @cascade(fields:["reputation","name"]) {
+						reputation
+                        name
+                        dob
+						posts @cascade(fields:["text"]) {
+						  title
+						  text
+						}
+					  }
+					}`,
+			variables: map[string]interface{}{"ids": authorIds},
+			respData: `{
+							"queryAuthor": [{
+								"reputation": 4.5,
+								 "name":"George",	
+                                 "dob": null,
+								"posts": [{
+									"title": "A show about nothing",
+									"text": "Got ya!"
+								}]
+							}, {
+                                  "dob": null,                                                    
+                                  "name": "Jerry",
+                                  "posts": [],
+                                  "reputation": 4.6
+							}]
+						}`,
+		},
 	}
 
 	for _, tcase := range tcases {
@@ -1842,6 +1947,7 @@ func queryWithCascade(t *testing.T) {
 
 	// cleanup
 	deleteAuthors(t, authorIds, nil)
+	deleteCountry(t, map[string]interface{}{"id": countryIds},len(countryIds), nil)
 	deleteGqlType(t, "Post", map[string]interface{}{"postID": postIds}, len(postIds), nil)
 	deleteState(t, getXidFilter("xcode", []string{states[0].Code, states[1].Code}), len(states),
 		nil)

graphql/resolve/query_test.yaml

@@ -743,6 +743,135 @@
       }
     }
 
+-
+  name: "Parameterized Cascade directive on filter query"
+  gqlquery: |
+    query {
+      queryAuthor @cascade(fields:["dob"]) {
+        dob
+        name
+        posts {
+          text
+        }
+      }
+    }
+  dgquery: |-
+    query {
+      queryAuthor(func: type(Author)) @cascade(Author.dob) {
+        dob : Author.dob
+        name : Author.name
+        posts : Author.posts {
+          text : Post.text
+          dgraph.uid : uid
+        }
+        dgraph.uid : uid
+      }
+    }
+
+-
+  name: "Parameterized Cascade directive on get query"
+  gqlquery: |
+    query {
+      getAuthor(id: "0x1") @cascade(fields:["dob"]) {
+        dob
+        name
+        posts {
+          text
+        }
+      }
+    }
+  dgquery: |-
+    query {
+      getAuthor(func: uid(0x1)) @filter(type(Author)) @cascade(Author.dob) {
+        dob : Author.dob
+        name : Author.name
+        posts : Author.posts {
+          text : Post.text
+          dgraph.uid : uid
+        }
+        dgraph.uid : uid
+      }
+    }
+
+-
+  name: "Parameterized Cascade directive on query field"
+  gqlquery: |
+    query {
+      queryAuthor {
+        dob
+        posts @cascade(fields:["text"]) {
+          text
+          title
+        }
+      }
+    }
+  dgquery: |-
+    query {
+      queryAuthor(func: type(Author)) {
+        dob : Author.dob
+        posts : Author.posts @cascade(Post.text) {
+          text : Post.text
+          title : Post.title
+          dgraph.uid : uid
+        }
+        dgraph.uid : uid
+      }
+    }
+
+-
+  name: "Parameterized Cascade directive on root and query field"
+  gqlquery: |
+    query {
+      queryAuthor @cascade(fields:["dob"]) {
+        dob
+        reputation
+        posts @cascade(fields:["text"]) {
+          text
+          title
+        }
+      }
+    }
+  dgquery: |-
+    query {
+      queryAuthor(func: type(Author)) @cascade(Author.dob) {
+        dob : Author.dob
+        reputation : Author.reputation
+        posts : Author.posts @cascade(Post.text) {
+          text : Post.text
+          title : Post.title
+          dgraph.uid : uid
+        }
+        dgraph.uid : uid
+      }
+    }
+
+-
+  name: "Parameterized Cascade directive with multiple parameters on root and query field"
+  gqlquery: |
+    query {
+      queryAuthor @cascade(fields:["dob","reputation"]) {
+        dob
+        reputation
+        posts @cascade(fields:["text","title"]) {
+          text
+          title
+        }
+      }
+    }
+  dgquery: |-
+    query {
+      queryAuthor(func: type(Author)) @cascade(Author.dob,Author.reputation) {
+        dob : Author.dob
+        reputation : Author.reputation
+        posts : Author.posts @cascade(Post.text,Post.title) {
+          text : Post.text
+          title : Post.title
+          dgraph.uid : uid
+        }
+        dgraph.uid : uid
+      }
+    }
+
 -
   name: "getHuman which implements an interface"
   gqlquery: |

graphql/schema/gqlschema.go

@@ -132,7 +132,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/rules.go

@@ -45,6 +45,7 @@ func init() {
 
 	validator.AddRule("Check variable type is correct", variableTypeCheck)
 	validator.AddRule("Check for list type value", listTypeCheck)
+	validator.AddRule("Check arguments of cascade directive", directiveArgumentsCheck)
 
 }
 

graphql/schema/testdata/schemagen/output/authorization.graphql

@@ -93,7 +93,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/testdata/schemagen/output/comments-and-descriptions.graphql

@@ -98,7 +98,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/testdata/schemagen/output/custom-mutation.graphql

@@ -86,7 +86,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/testdata/schemagen/output/custom-nested-types.graphql

@@ -103,7 +103,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/testdata/schemagen/output/custom-query-mixed-types.graphql

@@ -87,7 +87,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/testdata/schemagen/output/custom-query-not-dgraph-type.graphql

@@ -86,7 +86,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/testdata/schemagen/output/custom-query-with-dgraph-type.graphql

@@ -82,7 +82,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int

graphql/schema/testdata/schemagen/output/deprecated.graphql

@@ -82,7 +82,7 @@ directive @auth(
 	delete:AuthRule) on OBJECT
 directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
 directive @remote on OBJECT | INTERFACE
-directive @cascade on FIELD
+directive @cascade(fields :[String]) on FIELD
 
 input IntFilter {
 	eq: Int