feat(GraphQL): add support for IN filter

graphql/dgraph/graphquery.go

@@ -143,6 +143,15 @@ func writeRoot(b *strings.Builder, q *gql.GraphQuery) {
 	x.Check2(b.WriteRune(')'))
 }
 
+func writeFilterArguments(b *strings.Builder, args []gql.Arg) {
+	for i, arg := range args {
+		if i != 0 {
+			x.Check2(b.WriteString(", "))
+		}
+		x.Check2(b.WriteString(fmt.Sprintf("%s", arg.Value)))
+	}
+}
+
 func writeFilterFunction(b *strings.Builder, f *gql.Function) {
 	if f == nil {
 		return
@@ -151,10 +160,10 @@ func writeFilterFunction(b *strings.Builder, f *gql.Function) {
 	switch {
 	case f.Name == "uid":
 		writeUIDFunc(b, f.UID, f.Args)
-	case len(f.Args) == 1:
-		x.Check2(b.WriteString(fmt.Sprintf("%s(%s)", f.Name, f.Args[0].Value)))
-	case len(f.Args) == 2:
-		x.Check2(b.WriteString(fmt.Sprintf("%s(%s, %s)", f.Name, f.Args[0].Value, f.Args[1].Value)))
+	default:
+		x.Check2(b.WriteString(fmt.Sprintf("%s(", f.Name)))
+		writeFilterArguments(b, f.Args)
+		x.Check2(b.WriteRune(')'))
 	}
 }
 

graphql/e2e/common/common.go

@@ -297,6 +297,7 @@ func RunAll(t *testing.T) {
 	t.Run("multiple search indexes", multipleSearchIndexes)
 	t.Run("multiple search indexes wrong field", multipleSearchIndexesWrongField)
 	t.Run("hash search", hashSearch)
+	t.Run("in filter", InFilter)
 	t.Run("deep filter", deepFilter)
 	t.Run("deep has filter", deepHasFilter)
 	t.Run("many queries", manyQueries)

graphql/e2e/common/query.go

@@ -346,6 +346,66 @@ func allPosts(t *testing.T) []*post {
 	return result.QueryPost
 }
 
+func InFilter(t *testing.T) {
+	addStateParams := &GraphQLParams{
+		Query: `mutation addState($name1: String!, $code1: String!, $name2: String!, $code2: String! ) {
+			addState(input: [{name: $name1, xcode: $code1},{name: $name2, xcode: $code2}]) {
+				state {
+					xcode
+					name
+				}
+			}
+		}`,
+
+		Variables: map[string]interface{}{
+			"name1": "A State",
+			"code1": "abc",
+			"name2": "B State",
+			"code2": "def",
+		},
+	}
+
+	gqlResponse := addStateParams.ExecuteAsPost(t, GraphqlURL)
+	RequireNoGQLErrors(t, gqlResponse)
+
+	getStateParams := &GraphQLParams{
+		Query: `query{
+			queryState(filter: {xcode: {in: ["abc", "def"]}}){
+				xcode
+				name
+			}
+		}`,
+	}
+
+	gqlResponse = getStateParams.ExecuteAsPost(t, GraphqlURL)
+	RequireNoGQLErrors(t, gqlResponse)
+
+	var result struct {
+		QueryState []*state
+	}
+	err := json.Unmarshal([]byte(gqlResponse.Data), &result)
+	require.NoError(t, err)
+	require.Equal(t, 2, len(result.QueryState))
+
+	state1 := &state{
+		Name: "A State",
+		Code: "abc",
+	}
+	state2 := &state{
+		Name: "B State",
+		Code: "def",
+	}
+
+	expected := []*state{state1, state2}
+
+	if diff := cmp.Diff(expected, result.QueryState); diff != "" {
+		t.Errorf("result mismatch (-want +got):\n%s", diff)
+	}
+
+	deleteFilter := map[string]interface{}{"xcode": map[string]interface{}{"in": []string{"abc", "def"}}}
+	deleteGqlType(t, "State", deleteFilter, 2, nil)
+}
+
 func deepFilter(t *testing.T) {
 	getAuthorParams := &GraphQLParams{
 		Query: `query {

graphql/e2e/schema/generatedSchema.graphql

@@ -135,6 +135,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -143,6 +144,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

graphql/resolve/query_rewriter.go

@@ -1056,14 +1056,29 @@ func buildFilter(typ schema.Type, filter map[string]interface{}) *gql.FilterTree
 				// title: { anyofterms: "GraphQL" } ->  anyofterms(Post.title, "GraphQL")
 				// OR
 				// numLikes: { le: 10 } -> le(Post.numLikes, 10)
+
 				fn, val := first(dgFunc)
+				args := []gql.Arg{
+					{Value: typ.DgraphPredicate(field)},
+				}
+				switch fn {
+				// in takes List of Scalars as argument, for eg:
+				// code : { in: {"abc", "def", "ghi"} } -> eq(State.code,"abc","def","ghi")
+				case "in":
+					vals := val.([]interface{})
+					fn = "eq"
+
+					for _, v := range vals {
+						args = append(args, gql.Arg{Value: maybeQuoteArg(fn, v)})
+					}
+
+				default:
+					args = append(args, gql.Arg{Value: maybeQuoteArg(fn, val)})
+				}
 				ands = append(ands, &gql.FilterTree{
 					Func: &gql.Function{
 						Name: fn,
-						Args: []gql.Arg{
-							{Value: typ.DgraphPredicate(field)},
-							{Value: maybeQuoteArg(fn, val)},
-						},
+						Args: args,
 					},
 				})
 			case []interface{}:

graphql/resolve/query_test.yaml

@@ -1,3 +1,21 @@
+-
+  name: "in filter"
+  gqlquery: |
+    query {
+      queryState(filter: {code: {in: ["abc", "def", "ghi"]}}) {
+        code
+        name
+      }
+    }
+  dgquery: |-
+    query {
+      queryState(func: type(State)) @filter(eq(State.code, "abc", "def", "ghi")) {
+        code : State.code
+        name : State.name
+        dgraph.uid : uid
+      }
+    }
+
 -
   name: "ID query"
   gqlquery: |

graphql/schema/gqlschema.go

@@ -186,6 +186,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -194,6 +195,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 `
 )

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

@@ -146,6 +146,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -154,6 +155,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -151,6 +151,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -159,6 +160,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -139,6 +139,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -147,6 +148,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -156,6 +156,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -164,6 +165,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -140,6 +140,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -148,6 +149,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -139,6 +139,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -147,6 +148,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -135,6 +135,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -143,6 +144,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -135,6 +135,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -143,6 +144,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-on-concrete-type-with-interfaces.graphql

@@ -149,6 +149,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -157,6 +158,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-with-interfaces.graphql

@@ -149,6 +149,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -157,6 +158,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################

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

@@ -148,6 +148,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -156,6 +157,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################
@@ -332,6 +334,7 @@ input PostRef {
 
 input StringHashFilter_StringRegExpFilter {
 	eq: String
+	in: [String]
 	regexp: String
 }
 

graphql/schema/testdata/schemagen/output/field-with-reverse-predicate-in-dgraph-directive.graphql

@@ -142,6 +142,7 @@ input StringFullTextFilter {
 
 input StringExactFilter {
 	eq: String
+	in: [String]
 	le: String
 	lt: String
 	ge: String
@@ -150,6 +151,7 @@ input StringExactFilter {
 
 input StringHashFilter {
 	eq: String
+	in: [String]
 }
 
 #######################