Add @type directive to enforce type constraints. (hypermodeinc#3003)

Predicates in queries can now have a @type predicate that enforces that all the given results are of the given type. For now this is just the equivalent of filtering using the existing type function but later more checks will be added.
dna2fork · Jul 19, 2019 · 0eb2b2d · 0eb2b2d
1 parent 7dbbe84
commit 0eb2b2d
Show file tree

Hide file tree

Showing 4 changed files with 164 additions and 0 deletions.
diff --git a/gql/parser.go b/gql/parser.go
@@ -1880,6 +1880,40 @@ func parseGroupby(it *lex.ItemIterator, gq *GraphQuery) error {
 	return nil
 }
 
+func parseType(it *lex.ItemIterator, gq *GraphQuery) error {
+	it.Next()
+	if it.Item().Typ != itemLeftRound {
+		return it.Item().Errorf("Expected a left round after type")
+	}
+
+	it.Next()
+	if it.Item().Typ != itemName {
+		return it.Item().Errorf("Expected a type name inside type directive")
+	}
+	typeName := it.Item().Val
+
+	it.Next()
+	if it.Item().Typ != itemRightRound {
+		return it.Item().Errorf("Expected ) after the type name in type directive")
+	}
+
+	// For now @type(TypeName) is equivalent of filtering using the type function.
+	// Later the type declarations will be used to ensure that the fields inside
+	// each block correspond to the specified type.
+	gq.Filter = &FilterTree{
+		Func: &Function{
+			Name: "type",
+			Args: []Arg{
+				Arg{
+					Value: typeName,
+				},
+			},
+		},
+	}
+
+	return nil
+}
+
 // parseFilter parses the filter directive to produce a QueryFilter / parse tree.
 func parseFilter(it *lex.ItemIterator) (*FilterTree, error) {
 	it.Next()
@@ -2110,6 +2144,11 @@ func parseDirective(it *lex.ItemIterator, curp *GraphQuery) error {
 			}
 			curp.IsGroupby = true
 			parseGroupby(it, curp)
+		case "type":
+			err := parseType(it, curp)
+			if err != nil {
+				return err
+			}
 		default:
 			return item.Errorf("Unknown directive [%s]", item.Val)
 		}

diff --git a/gql/parser_test.go b/gql/parser_test.go
@@ -4527,3 +4527,81 @@ func TestTypeInFilter(t *testing.T) {
 	require.Equal(t, 1, len(gq.Query[0].Filter.Func.Args))
 	require.Equal(t, "Person", gq.Query[0].Filter.Func.Args[0].Value)
 }
+
+func TestTypeFilterInPredicate(t *testing.T) {
+	q := `
+	query {
+		me(func: uid(0x01)) {
+			friend @filter(type(Person)) {
+				name
+			}
+		}
+	}`
+	gq, err := Parse(Request{Str: q})
+	require.NoError(t, err)
+	require.Equal(t, 1, len(gq.Query))
+	require.Equal(t, "uid", gq.Query[0].Func.Name)
+	require.Equal(t, 1, len(gq.Query[0].Children))
+	require.Equal(t, "friend", gq.Query[0].Children[0].Attr)
+
+	require.Equal(t, "type", gq.Query[0].Children[0].Filter.Func.Name)
+	require.Equal(t, 1, len(gq.Query[0].Children[0].Filter.Func.Args))
+	require.Equal(t, "Person", gq.Query[0].Children[0].Filter.Func.Args[0].Value)
+
+	require.Equal(t, 1, len(gq.Query[0].Children[0].Children))
+	require.Equal(t, "name", gq.Query[0].Children[0].Children[0].Attr)
+}
+
+func TestTypeInPredicate(t *testing.T) {
+	q := `
+	query {
+		me(func: uid(0x01)) {
+			friend @type(Person) {
+				name
+			}
+		}
+	}`
+	gq, err := Parse(Request{Str: q})
+	require.NoError(t, err)
+	require.Equal(t, 1, len(gq.Query))
+	require.Equal(t, "uid", gq.Query[0].Func.Name)
+	require.Equal(t, 1, len(gq.Query[0].Children))
+	require.Equal(t, "friend", gq.Query[0].Children[0].Attr)
+
+	require.Equal(t, "type", gq.Query[0].Children[0].Filter.Func.Name)
+	require.Equal(t, 1, len(gq.Query[0].Children[0].Filter.Func.Args))
+	require.Equal(t, "Person", gq.Query[0].Children[0].Filter.Func.Args[0].Value)
+
+	require.Equal(t, 1, len(gq.Query[0].Children[0].Children))
+	require.Equal(t, "name", gq.Query[0].Children[0].Children[0].Attr)
+}
+
+func TestMultipleTypeDirectives(t *testing.T) {
+	q := `
+	query {
+		me(func: uid(0x01)) {
+			friend @type(Person) {
+				pet @type(Animal) {
+					name
+				}
+			}
+		}
+	}`
+	gq, err := Parse(Request{Str: q})
+	require.NoError(t, err)
+	require.Equal(t, 1, len(gq.Query))
+	require.Equal(t, "uid", gq.Query[0].Func.Name)
+	require.Equal(t, 1, len(gq.Query[0].Children))
+	require.Equal(t, "friend", gq.Query[0].Children[0].Attr)
+
+	require.Equal(t, "type", gq.Query[0].Children[0].Filter.Func.Name)
+	require.Equal(t, 1, len(gq.Query[0].Children[0].Filter.Func.Args))
+	require.Equal(t, "Person", gq.Query[0].Children[0].Filter.Func.Args[0].Value)
+
+	require.Equal(t, 1, len(gq.Query[0].Children[0].Children))
+	require.Equal(t, "pet", gq.Query[0].Children[0].Children[0].Attr)
+
+	require.Equal(t, "type", gq.Query[0].Children[0].Children[0].Filter.Func.Name)
+	require.Equal(t, 1, len(gq.Query[0].Children[0].Children[0].Filter.Func.Args))
+	require.Equal(t, "Animal", gq.Query[0].Children[0].Children[0].Filter.Func.Args[0].Value)
+}
diff --git a/query/common_test.go b/query/common_test.go
@@ -202,6 +202,7 @@ symbol                         : string @index(exact) .
 room                           : string @index(term) .
 office.room                    : [uid] .
 best_friend                    : uid .
+pet                            : [uid] .
 `
 
 func populateCluster(t *testing.T) {
@@ -211,6 +212,12 @@ func populateCluster(t *testing.T) {
 
 	addTriplesToCluster(t, `
 		<1> <name> "Michonne" .
+		<2> <name> "King Lear" .
+		<3> <name> "Margaret" .
+		<4> <name> "Leonard" .
+		<5> <name> "Garfield" .
+		<6> <name> "Bear" .
+		<7> <name> "Nemo" .
 		<23> <name> "Rick Grimes" .
 		<24> <name> "Glenn Rhee" .
 		<25> <name> "Daryl Dixon" .
@@ -425,6 +432,15 @@ func populateCluster(t *testing.T) {
 		<2> <type> "Person" .
 		<3> <type> "Person" .
 		<4> <type> "Person" .
+		<5> <type> "Animal" .
+		<6> <type> "Animal" .
+
+		<2> <pet> <5> .
+		<3> <pet> <6> .
+		<4> <pet> <7> .
+
+		<2> <enemy> <3> .
+		<2> <enemy> <4> .
 	`)
 
 	addGeoPointToCluster(t, 1, "loc", []float64{1.1, 2.0})

diff --git a/query/query3_test.go b/query/query3_test.go
@@ -1913,3 +1913,34 @@ func TestTypeFilterUnknownType(t *testing.T) {
 	js := processQueryNoErr(t, query)
 	require.JSONEq(t, `{"data": {"me":[]}}`, js)
 }
+
+func TestTypeDirectiveInPredicate(t *testing.T) {
+	query := `
+		{
+			me(func: uid(0x2)) {
+				enemy @type(Person) {
+					name
+				}
+			}
+		}
+	`
+	js := processQueryNoErr(t, query)
+	require.JSONEq(t, `{"data": {"me":[{"enemy":[{"name":"Margaret"}, {"name":"Leonard"}]}]}}`, js)
+}
+
+func TestMultipleTypeDirectivesInPredicate(t *testing.T) {
+	query := `
+		{
+			me(func: uid(0x2)) {
+				enemy @type(Person) {
+					name
+					pet @type(Animal) {
+						name
+					}
+				}
+			}
+		}
+	`
+	js := processQueryNoErr(t, query)
+	require.JSONEq(t, `{"data": {"me":[{"enemy":[{"name":"Margaret", "pet":[{"name":"Bear"}]}, {"name":"Leonard"}]}]}}`, js)
+}