fix(GRAPHQL):[Breaking] Don't generate get query on interface if it d…

…oesn't have field of type ID and also disallow get query on field of type @id in inerface. (#7158)

Fixes GRAPHQL-886
We were allowing get query on the field of type @id on the interface type. This causes an error in cases when interface is implemented by multiple types and they try to have same value for field of type @id.
To resolve this we are disallowing get query on the interface if it doesn't have a field of type ID , and if we have both fields of type ID and @id then we don't allow get query on the field of type @id.

graphql/schema/gqlschema.go

@@ -1732,7 +1732,7 @@ func addAggregationResultType(schema *ast.Schema, defn *ast.Definition) {
 func addGetQuery(schema *ast.Schema, defn *ast.Definition, generateSubscription bool) {
 	hasIDField := hasID(defn)
 	hasXIDField := hasXID(defn)
-	if !hasIDField && !hasXIDField {
+	if !hasIDField && (defn.Kind == "INTERFACE" || !hasXIDField) {
 		return
 	}
 
@@ -1755,7 +1755,7 @@ func addGetQuery(schema *ast.Schema, defn *ast.Definition, generateSubscription
 			},
 		})
 	}
-	if hasXIDField {
+	if hasXIDField && defn.Kind != "INTERFACE" {
 		name, dtype := xidTypeFor(defn)
 		qry.Arguments = append(qry.Arguments, &ast.ArgumentDefinition{
 			Name: name,

graphql/schema/testdata/schemagen/input/interface-with-id-directive-and-ID-field.graphql

@@ -0,0 +1,5 @@
+interface Student {
+    rollNo: String! @id
+    regNo: ID!
+    name: String!
+}

graphql/schema/testdata/schemagen/output/interface-with-id-directive-and-ID-field.graphql

@@ -0,0 +1,356 @@
+#######################
+# Input Schema
+#######################
+
+interface Student {
+	rollNo: String! @id
+	regNo: ID!
+	name: String!
+}
+
+#######################
+# Extended Definitions
+#######################
+
+"""
+The Int64 scalar type represents a signed 64‐bit numeric non‐fractional value.
+Int64 can represent values in range [-(2^63),(2^63 - 1)].
+"""
+scalar Int64
+
+"""
+The DateTime scalar type represents date and time as a string in RFC3339 format.
+For example: "1985-04-12T23:20:50.52Z" represents 20 minutes and 50.52 seconds after the 23rd hour of April 12th, 1985 in UTC.
+"""
+scalar DateTime
+
+input IntRange{
+	min: Int!
+	max: Int!
+}
+
+input FloatRange{
+	min: Float!
+	max: Float!
+}
+
+input Int64Range{
+	min: Int64!
+	max: Int64!
+}
+
+input DateTimeRange{
+	min: DateTime!
+	max: DateTime!
+}
+
+input StringRange{
+	min: String!
+	max: String!
+}
+
+enum DgraphIndex {
+	int
+	int64
+	float
+	bool
+	hash
+	exact
+	term
+	fulltext
+	trigram
+	regexp
+	year
+	month
+	day
+	hour
+	geo
+}
+
+input AuthRule {
+	and: [AuthRule]
+	or: [AuthRule]
+	not: AuthRule
+	rule: String
+}
+
+enum HTTPMethod {
+	GET
+	POST
+	PUT
+	PATCH
+	DELETE
+}
+
+enum Mode {
+	BATCH
+	SINGLE
+}
+
+input CustomHTTP {
+	url: String!
+	method: HTTPMethod!
+	body: String
+	graphql: String
+	mode: Mode
+	forwardHeaders: [String!]
+	secretHeaders: [String!]
+	introspectionHeaders: [String!]
+	skipIntrospection: Boolean
+}
+
+type Point {
+	longitude: Float!
+	latitude: Float!
+}
+
+input PointRef {
+	longitude: Float!
+	latitude: Float!
+}
+
+input NearFilter {
+	distance: Float!
+	coordinate: PointRef!
+}
+
+input PointGeoFilter {
+	near: NearFilter
+	within: WithinFilter
+}
+
+type PointList {
+	points: [Point!]!
+}
+
+input PointListRef {
+	points: [PointRef!]!
+}
+
+type Polygon {
+	coordinates: [PointList!]!
+}
+
+input PolygonRef {
+	coordinates: [PointListRef!]!
+}
+
+type MultiPolygon {
+	polygons: [Polygon!]!
+}
+
+input MultiPolygonRef {
+	polygons: [PolygonRef!]!
+}
+
+input WithinFilter {
+	polygon: PolygonRef!
+}
+
+input ContainsFilter {
+	point: PointRef
+	polygon: PolygonRef
+}
+
+input IntersectsFilter {
+	polygon: PolygonRef
+	multiPolygon: MultiPolygonRef
+}
+
+input PolygonGeoFilter {
+	near: NearFilter
+	within: WithinFilter
+	contains: ContainsFilter
+	intersects: IntersectsFilter
+}
+
+input GenerateQueryParams {
+	get: Boolean
+	query: Boolean
+	password: Boolean
+	aggregate: Boolean
+}
+
+input GenerateMutationParams {
+	add: Boolean
+	update: Boolean
+	delete: Boolean
+}
+
+directive @hasInverse(field: String!) on FIELD_DEFINITION
+directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
+directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
+directive @id on FIELD_DEFINITION
+directive @withSubscription on OBJECT | INTERFACE
+directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
+directive @auth(
+	password: AuthRule
+	query: AuthRule,
+	add: AuthRule,
+	update: AuthRule,
+	delete: AuthRule) on OBJECT | INTERFACE
+directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
+directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
+directive @cascade(fields: [String]) on FIELD
+directive @lambda on FIELD_DEFINITION
+directive @cacheControl(maxAge: Int!) on QUERY
+directive @generate(
+	query: GenerateQueryParams,
+	mutation: GenerateMutationParams,
+	subscription: Boolean) on OBJECT | INTERFACE
+
+input IntFilter {
+	eq: Int
+	le: Int
+	lt: Int
+	ge: Int
+	gt: Int
+	between: IntRange
+}
+
+input Int64Filter {
+	eq: Int64
+	le: Int64
+	lt: Int64
+	ge: Int64
+	gt: Int64
+	between: Int64Range
+}
+
+input FloatFilter {
+	eq: Float
+	le: Float
+	lt: Float
+	ge: Float
+	gt: Float
+	between: FloatRange
+}
+
+input DateTimeFilter {
+	eq: DateTime
+	le: DateTime
+	lt: DateTime
+	ge: DateTime
+	gt: DateTime
+	between: DateTimeRange
+}
+
+input StringTermFilter {
+	allofterms: String
+	anyofterms: String
+}
+
+input StringRegExpFilter {
+	regexp: String
+}
+
+input StringFullTextFilter {
+	alloftext: String
+	anyoftext: String
+}
+
+input StringExactFilter {
+	eq: String
+	in: [String]
+	le: String
+	lt: String
+	ge: String
+	gt: String
+	between: StringRange
+}
+
+input StringHashFilter {
+	eq: String
+	in: [String]
+}
+
+#######################
+# Generated Types
+#######################
+
+type DeleteStudentPayload {
+	student(filter: StudentFilter, order: StudentOrder, first: Int, offset: Int): [Student]
+	msg: String
+	numUids: Int
+}
+
+type StudentAggregateResult {
+	count: Int
+	rollNoMin: String
+	rollNoMax: String
+	nameMin: String
+	nameMax: String
+}
+
+type UpdateStudentPayload {
+	student(filter: StudentFilter, order: StudentOrder, first: Int, offset: Int): [Student]
+	numUids: Int
+}
+
+#######################
+# Generated Enums
+#######################
+
+enum StudentHasFilter {
+	rollNo
+	name
+}
+
+enum StudentOrderable {
+	rollNo
+	name
+}
+
+#######################
+# Generated Inputs
+#######################
+
+input StudentFilter {
+	rollNo: StringHashFilter
+	regNo: [ID!]
+	has: StudentHasFilter
+	and: [StudentFilter]
+	or: [StudentFilter]
+	not: StudentFilter
+}
+
+input StudentOrder {
+	asc: StudentOrderable
+	desc: StudentOrderable
+	then: StudentOrder
+}
+
+input StudentPatch {
+	name: String
+}
+
+input StudentRef {
+	regNo: ID
+	rollNo: String @id
+}
+
+input UpdateStudentInput {
+	filter: StudentFilter!
+	set: StudentPatch
+	remove: StudentPatch
+}
+
+#######################
+# Generated Query
+#######################
+
+type Query {
+	getStudent(regNo: ID): Student
+	queryStudent(filter: StudentFilter, order: StudentOrder, first: Int, offset: Int): [Student]
+	aggregateStudent(filter: StudentFilter): StudentAggregateResult
+}
+
+#######################
+# Generated Mutations
+#######################
+
+type Mutation {
+	updateStudent(input: UpdateStudentInput!): UpdateStudentPayload
+	deleteStudent(filter: StudentFilter!): DeleteStudentPayload
+}
+

graphql/schema/testdata/schemagen/output/interface-with-id-directive.graphql

@@ -452,7 +452,6 @@ input UpdateLibraryInput {
 #######################
 
 type Query {
-	getLibraryItem(refID: String!): LibraryItem
 	queryLibraryItem(filter: LibraryItemFilter, order: LibraryItemOrder, first: Int, offset: Int): [LibraryItem]
 	aggregateLibraryItem(filter: LibraryItemFilter): LibraryItemAggregateResult
 	getBook(refID: String!): Book