Merge pull request #16 from dgraph-io/anurags92/gwlparserfix

fix(Parser): Add directive argument validator

Author: all-seeing-code

validator/schema.go

@@ -289,6 +289,21 @@ func validateArgs(schema *Schema, args ArgumentDefinitionList, currentDirective
 	return nil
 }
 
+func validateDirectiveArgs(dir *Directive, schema *Schema) *gqlerror.Error {
+	allowedArgs := make(map[string]struct{})
+	for _, arg := range schema.Directives[dir.Name].Arguments {
+		allowedArgs[arg.Name] = struct{}{}
+	}
+
+	for _, arg := range dir.Arguments {
+		if _, ok := allowedArgs[arg.Name]; !ok {
+			return gqlerror.ErrorPosf(dir.Position, "%s is not supported as an argument for %s directive.", arg.Name, dir.Name)
+		}
+	}
+	return nil
+
+}
+
 func validateDirectives(schema *Schema, dirs DirectiveList, location DirectiveLocation, currentDirective *DirectiveDefinition) *gqlerror.Error {
 	for _, dir := range dirs {
 		if err := validateName(dir.Position, dir.Name); err != nil {
@@ -301,6 +316,9 @@ func validateDirectives(schema *Schema, dirs DirectiveList, location DirectiveLo
 		if schema.Directives[dir.Name] == nil {
 			return gqlerror.ErrorPosf(dir.Position, "Undefined directive %s.", dir.Name)
 		}
+		if err := validateDirectiveArgs(dir, schema); err != nil {
+			return err
+		}
 		validKind := false
 		for _, dirLocation := range schema.Directives[dir.Name].Locations {
 			if dirLocation == location {

validator/schema_test.yml

@@ -505,6 +505,16 @@ directives:
 
       directive @A(a: Input, b: Scalar, c: Enum) on FIELD_DEFINITION
 
+  - name: Valid arg for directive
+    input: |
+      type User @include(aggregate: false) {
+        name: String
+      }
+
+    error:
+      message: 'aggregate is not supported as an argument for include directive.'
+      locations: [{line: 1, column: 12}]
+
   - name: Objects not allowed
     input: |
       type Object { id: ID }