fix(GraphQL): This PR addd input coercion from single object to list and fix panic when we pass single ID in filter as a string.

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/dgraph-io/badger/v2 v2.0.1-rc1.0.20201214114056-bcfae6104545
 	github.com/dgraph-io/dgo/v200 v200.0.0-20200805103119-a3544c464dd6
 	github.com/dgraph-io/gqlgen v0.13.2
-	github.com/dgraph-io/gqlparser/v2 v2.1.1
+	github.com/dgraph-io/gqlparser/v2 v2.1.2
 	github.com/dgraph-io/graphql-transport-ws v0.0.0-20200916064635-48589439591b
 	github.com/dgraph-io/ristretto v0.0.4-0.20201207174236-c72a155bcf05
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible

go.sum

@@ -122,8 +122,9 @@ github.com/dgraph-io/dgo/v200 v200.0.0-20200805103119-a3544c464dd6 h1:toHzMCdCUg
 github.com/dgraph-io/dgo/v200 v200.0.0-20200805103119-a3544c464dd6/go.mod h1:rHa+h3kI4M8ASOirxyIyNeXBfHFgeskVUum2OrDMN3U=
 github.com/dgraph-io/gqlgen v0.13.2 h1:TNhndk+eHKj5qE7BenKKSYdSIdOGhLqxR1rCiMso9KM=
 github.com/dgraph-io/gqlgen v0.13.2/go.mod h1:iCOrOv9lngN7KAo+jMgvUPVDlYHdf7qDwsTkQby2Sis=
-github.com/dgraph-io/gqlparser/v2 v2.1.1 h1:OBGI6VR+WcegjDB3JdNPMpKpEtITHWzgmiCXtELWolI=
 github.com/dgraph-io/gqlparser/v2 v2.1.1/go.mod h1:MYS4jppjyx8b9tuUtjV7jU1UFZK6P9fvO8TsIsQtRKU=
+github.com/dgraph-io/gqlparser/v2 v2.1.2 h1:N7dyP6Y2ScsyQjqw5+wjPJOsAmZE1q8TcMvsPClaFV4=
+github.com/dgraph-io/gqlparser/v2 v2.1.2/go.mod h1:MYS4jppjyx8b9tuUtjV7jU1UFZK6P9fvO8TsIsQtRKU=
 github.com/dgraph-io/graphql-transport-ws v0.0.0-20200916064635-48589439591b h1:PDEhlwHpkEQ5WBfOOKZCNZTXFDGyCEWTYDhxGQbyIpk=
 github.com/dgraph-io/graphql-transport-ws v0.0.0-20200916064635-48589439591b/go.mod h1:7z3c/5w0sMYYZF5bHsrh8IH4fKwG5O5Y70cPH1ZLLRQ=
 github.com/dgraph-io/ristretto v0.0.4-0.20201205013540-bafef7527542/go.mod h1:tv2ec8nA7vRpSYX7/MbP52ihrUMXIHit54CQMq8npXQ=

graphql/e2e/common/common.go

@@ -658,7 +658,7 @@ func RunAll(t *testing.T) {
 	t.Run("query id directive with int", idDirectiveWithInt)
 	t.Run("query id directive with int64", idDirectiveWithInt64)
 	t.Run("query id directive with float", idDirectiveWithFloat)
-
+	t.Run("query using single ID in a filter that will be coerced to list", queryFilterSingleIDListCoercion)
 	// mutation tests
 	t.Run("add mutation", addMutation)
 	t.Run("update mutation by ids", updateMutationByIds)

graphql/e2e/common/query.go

@@ -3284,6 +3284,72 @@ func passwordTest(t *testing.T) {
 	deleteUser(t, *newUser)
 }
 
+func queryFilterSingleIDListCoercion(t *testing.T) {
+	authors := addMultipleAuthorFromRef(t, []*author{
+		{
+			Name:          "George",
+			Reputation:    4.5,
+			Qualification: "Phd in CSE",
+			Posts:         []*post{{Title: "A show about nothing", Text: "Got ya!", Tags: []string{}}},
+		}, {
+			Name:       "Jerry",
+			Reputation: 4.6,
+			Country:    &country{Name: "outer Galaxy2"},
+			Posts:      []*post{{Title: "Outside", Tags: []string{}}},
+		},
+	}, postExecutor)
+	authorIds := []string{authors[0].ID, authors[1].ID}
+	postIds := []string{authors[0].Posts[0].PostID, authors[1].Posts[0].PostID}
+	countryIds := []string{authors[1].Country.ID}
+	tcase := struct {
+		name      string
+		query     string
+		variables map[string]interface{}
+		respData  string
+	}{
+
+		name: "Query using single ID in a filter",
+		query: `query($filter:AuthorFilter){
+                      queryAuthor(filter:$filter){
+                        name
+						reputation
+                        posts {
+                          text
+                        }
+                      }
+				    }`,
+		variables: map[string]interface{}{"filter": map[string]interface{}{"id": authors[0].ID}},
+		respData: `{
+						  "queryAuthor": [
+							{
+							  "name": "George",
+							  "reputation": 4.5,
+							  "posts": [
+								{
+								  "text": "Got ya!"
+								}
+							  ]
+							}
+						  ]
+						}`,
+	}
+
+	t.Run(tcase.name, func(t *testing.T) {
+		params := &GraphQLParams{
+			Query:     tcase.query,
+			Variables: tcase.variables,
+		}
+		resp := params.ExecuteAsPost(t, GraphqlURL)
+		RequireNoGQLErrors(t, resp)
+		testutil.CompareJSON(t, tcase.respData, string(resp.Data))
+	})
+
+	// 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)
+}
+
 func idDirectiveWithInt64(t *testing.T) {
 	query := &GraphQLParams{
 		Query: `query {

graphql/resolve/mutation_rewriter.go

@@ -263,15 +263,7 @@ func (xidMetadata *xidMetadata) isDuplicateXid(atTopLevel bool, xidVar string,
 // }
 func (mrw *AddRewriter) Rewrite(ctx context.Context, m schema.Mutation) ([]*UpsertMutation, error) {
 	mutatedType := m.MutatedType()
-	var val []interface{}
-
-	switch v := m.ArgValue(schema.InputArgName).(type) {
-	case []interface{}:
-		val = v
-	case interface{}:
-		val = append(val, v)
-	}
-
+	val, _ := m.ArgValue(schema.InputArgName).([]interface{})
 	varGen := NewVariableGenerator()
 	xidMd := newXidMetadata()
 	var errs error

graphql/resolve/query_rewriter.go

@@ -1563,11 +1563,6 @@ func buildFilter(typ schema.Type, filter map[string]interface{}) *gql.FilterTree
 					ft := buildFilter(typ, obj.(map[string]interface{}))
 					ands = append(ands, ft)
 				}
-			case []map[string]interface{}:
-				for _, obj := range v {
-					ft := buildFilter(typ, obj)
-					ands = append(ands, ft)
-				}
 			}
 		case "or":
 			// title: { anyofterms: "GraphQL" }, or: { ... }
@@ -1592,16 +1587,6 @@ func buildFilter(typ schema.Type, filter map[string]interface{}) *gql.FilterTree
 					Child: ors,
 					Op:    "or",
 				}
-			case []map[string]interface{}:
-				ors := make([]*gql.FilterTree, 0, len(v))
-				for _, obj := range v {
-					ft := buildFilter(typ, obj)
-					ors = append(ands, ft)
-				}
-				or = &gql.FilterTree{
-					Child: ors,
-					Op:    "or",
-				}
 			}
 		case "not":
 			// title: { anyofterms: "GraphQL" }, not: { isPublished: true}

graphql/resolve/query_test.yaml

@@ -916,7 +916,7 @@
     }
   dgquery: |-
     query {
-      queryAuthor(func: type(Author)) @filter((eq(Author.name, "A. N. Author") OR le(Author.dob, "2001-01-01"))) {
+      queryAuthor(func: type(Author)) @filter((eq(Author.name, "A. N. Author") OR (le(Author.dob, "2001-01-01")))) {
         name : Author.name
         dgraph.uid : uid
       }
@@ -948,7 +948,7 @@
     }
   dgquery: |-
     query {
-      queryAuthor(func: type(Author)) @filter(eq(Author.name, "A. N. Author")) {
+      queryAuthor(func: type(Author)) @filter((eq(Author.name, "A. N. Author"))) {
         name : Author.name
         dgraph.uid : uid
       }
@@ -965,7 +965,7 @@
     }
   dgquery: |-
     query {
-      queryAuthor(func: type(Author)) @filter(((eq(Author.name, "A. N. Author") AND gt(Author.reputation, "2.5")) OR le(Author.dob, "2001-01-01"))) {
+      queryAuthor(func: type(Author)) @filter(((eq(Author.name, "A. N. Author") AND gt(Author.reputation, "2.5")) OR (le(Author.dob, "2001-01-01")))) {
         name : Author.name
         dgraph.uid : uid
       }
@@ -981,7 +981,7 @@
     }
   dgquery: |-
     query {
-      queryAuthor(func: type(Author)) @filter((eq(Author.name, "A. N. Author") OR (le(Author.dob, "2001-01-01") AND gt(Author.reputation, "2.5")))) {
+      queryAuthor(func: type(Author)) @filter((eq(Author.name, "A. N. Author") OR ((le(Author.dob, "2001-01-01") AND gt(Author.reputation, "2.5"))))) {
         name : Author.name
         dgraph.uid : uid
       }
@@ -997,7 +997,7 @@
     }
   dgquery: |-
     query {
-      queryAuthor(func: type(Author)) @filter((eq(Author.name, "A. N. Author") OR (gt(Author.reputation, "2.5") OR le(Author.dob, "2001-01-01")))) {
+      queryAuthor(func: type(Author)) @filter((eq(Author.name, "A. N. Author") OR ((gt(Author.reputation, "2.5") OR (le(Author.dob, "2001-01-01")))))) {
         name : Author.name
         dgraph.uid : uid
       }
@@ -1257,7 +1257,7 @@
     }
   dgquery: |-
     query {
-      queryAuthor(func: type(Author)) @filter((gt(Author.reputation, "1.1") OR (ge(Author.reputation, "1.1") OR (lt(Author.reputation, "1.1") OR (le(Author.reputation, "1.1") OR eq(Author.reputation, "1.1")))))) {
+      queryAuthor(func: type(Author)) @filter((gt(Author.reputation, "1.1") OR ((ge(Author.reputation, "1.1") OR ((lt(Author.reputation, "1.1") OR ((le(Author.reputation, "1.1") OR (eq(Author.reputation, "1.1")))))))))) {
         name : Author.name
         dgraph.uid : uid
       }
@@ -1273,7 +1273,7 @@
     }
   dgquery: |-
     query {
-      queryAuthor(func: type(Author)) @filter((gt(Author.dob, "2000-01-01") OR (ge(Author.dob, "2000-01-01") OR (lt(Author.dob, "2000-01-01") OR (le(Author.dob, "2000-01-01") OR eq(Author.dob, "2000-01-01")))))) {
+      queryAuthor(func: type(Author)) @filter((gt(Author.dob, "2000-01-01") OR ((ge(Author.dob, "2000-01-01") OR ((lt(Author.dob, "2000-01-01") OR ((le(Author.dob, "2000-01-01") OR (eq(Author.dob, "2000-01-01")))))))))) {
         name : Author.name
         dgraph.uid : uid
       }
@@ -1289,7 +1289,7 @@
     }
   dgquery: |-
     query {
-      queryPost(func: type(Post)) @filter((gt(Post.numLikes, 10) OR (ge(Post.numLikes, 10) OR (lt(Post.numLikes, 10) OR (le(Post.numLikes, 10) OR eq(Post.numLikes, 10)))))) {
+      queryPost(func: type(Post)) @filter((gt(Post.numLikes, 10) OR ((ge(Post.numLikes, 10) OR ((lt(Post.numLikes, 10) OR ((le(Post.numLikes, 10) OR (eq(Post.numLikes, 10)))))))))) {
         title : Post.title
         dgraph.uid : uid
       }
@@ -1321,7 +1321,7 @@
     }
   dgquery: |-
     query {
-      queryCountry(func: type(Country)) @filter((gt(Country.name, "AAA") OR (ge(Country.name, "AAA") OR (lt(Country.name, "AAA") OR (le(Country.name, "AAA") OR eq(Country.name, "AAA")))))) {
+      queryCountry(func: type(Country)) @filter((gt(Country.name, "AAA") OR ((ge(Country.name, "AAA") OR ((lt(Country.name, "AAA") OR ((le(Country.name, "AAA") OR (eq(Country.name, "AAA")))))))))) {
         name : Country.name
         dgraph.uid : uid
       }
@@ -1370,7 +1370,7 @@
     }
   dgquery: |-
     query {
-      queryCountry(func: type(Country)) @filter(((gt(Country.name, "AAA") OR lt(Country.name, "XXX")) AND (gt(Country.name, "CCC") OR lt(Country.name, "MMM")))) {
+      queryCountry(func: type(Country)) @filter(((gt(Country.name, "AAA") OR (lt(Country.name, "XXX"))) AND (gt(Country.name, "CCC") OR (lt(Country.name, "MMM"))))) {
         name : Country.name
         dgraph.uid : uid
       }
@@ -1386,7 +1386,7 @@
     }
   dgquery: |-
     query {
-      queryPost(func: type(Post)) @filter((anyofterms(Post.title, "GraphQL") OR allofterms(Post.title, "GraphQL"))) {
+      queryPost(func: type(Post)) @filter((anyofterms(Post.title, "GraphQL") OR (allofterms(Post.title, "GraphQL")))) {
         title : Post.title
         dgraph.uid : uid
       }
@@ -1403,7 +1403,7 @@
     }
   dgquery: |-
     query {
-      queryPost(func: type(Post)) @filter((anyoftext(Post.text, "GraphQL") OR alloftext(Post.text, "GraphQL"))) {
+      queryPost(func: type(Post)) @filter((anyoftext(Post.text, "GraphQL") OR (alloftext(Post.text, "GraphQL")))) {
         title : Post.title
         dgraph.uid : uid
       }
@@ -3129,3 +3129,19 @@
         scoreVar as Tweets.score
       }
     }
+
+-
+  name: "query using single ID in filter"
+  gqlquery: |
+      query {
+        queryAuthor(filter:{id: "0x1"}) {
+          name
+          }
+        }
+  dgquery: |-
+    query {
+      queryAuthor(func: uid(0x1)) @filter(type(Author)) {
+        name : Author.name
+        dgraph.uid : uid
+      }
+    }

graphql/schema/rules.go

@@ -46,6 +46,7 @@ func init() {
 	validator.AddRule("Check variable type is correct", variableTypeCheck)
 	validator.AddRule("Check arguments of cascade directive", directiveArgumentsCheck)
 	validator.AddRule("Check range for Int type", intRangeCheck)
+	validator.AddRule("Input Coercion to List", listInputCoercion)
 
 }
 

graphql/schema/validation_rules.go

@@ -24,6 +24,28 @@ import (
 	"github.com/dgraph-io/gqlparser/v2/validator"
 )
 
+func listInputCoercion(observers *validator.Events, addError validator.AddErrFunc) {
+	observers.OnValue(func(walker *validator.Walker, value *ast.Value) {
+		if value.Definition == nil || value.ExpectedType == nil {
+			return
+		}
+
+		if value.Kind == ast.Variable {
+			return
+		}
+		// If the expected value is a list (ExpectedType.Elem != nil) && the value is not of list type,
+		// then we need to coerce the value to a list, otherwise, we can return here as we do below.
+
+		if !(value.ExpectedType.Elem != nil && value.Kind != ast.ListValue) {
+			return
+		}
+		val := *value
+		child := &ast.ChildValue{Value: &val}
+		valueNew := ast.Value{Children: []*ast.ChildValue{child}, Kind: ast.ListValue, Position: val.Position, Definition: val.Definition}
+		*value = valueNew
+	})
+}
+
 func variableTypeCheck(observers *validator.Events, addError validator.AddErrFunc) {
 	observers.OnValue(func(walker *validator.Walker, value *ast.Value) {
 		if value.Definition == nil || value.ExpectedType == nil ||