Include variables passed to directives in query plan steps (#206)

* gofmt -s
* Add failing test for variables passed to @include
* Fix test

execute_test.go

@@ -44,13 +44,14 @@ func TestExecutor_plansOfOne(t *testing.T) {
 							},
 						},
 						// return a known value we can test against
-						Queryer: &graphql.MockSuccessQueryer{Value: map[string]interface{}{
-							"values": []string{
-								"hello",
-								"world",
+						Queryer: &graphql.MockSuccessQueryer{
+							Value: map[string]interface{}{
+								"values": []string{
+									"hello",
+									"world",
+								},
 							},
 						},
-						},
 					},
 				},
 			},
@@ -90,7 +91,6 @@ func TestExecutor_plansWithDependencies(t *testing.T) {
 			RootStep: &QueryPlanStep{
 				Then: []*QueryPlanStep{
 					{
-
 						// this is equivalent to
 						// query { user }
 						ParentType:     typeNameQuery,
@@ -1146,7 +1146,6 @@ func TestExecutor_insertIntoInlineFragmentsList(t *testing.T) {
 			},
 		},
 	}, result)
-
 }
 
 func TestExecutor_insertIntoLists(t *testing.T) {
@@ -1760,7 +1759,6 @@ func TestExecutor_includeIf(t *testing.T) {
 			RootStep: &QueryPlanStep{
 				Then: []*QueryPlanStep{
 					{
-
 						// this is equivalent to
 						// query { user }
 						ParentType:     typeNameQuery,
@@ -2020,6 +2018,7 @@ func TestExecutor_threadsVariables(t *testing.T) {
 		t.Error(err.Error())
 	}
 }
+
 func TestFindInsertionPoint_rootList(t *testing.T) {
 	t.Parallel()
 	// in this example, the step before would have just resolved (need to be inserted at)
@@ -2525,7 +2524,7 @@ func TestFindInsertionPoint_handlesNullObjects(t *testing.T) {
 
 func TestSingleObjectWithColonInID(t *testing.T) {
 	t.Parallel()
-	var source = make(map[string]interface{})
+	source := make(map[string]interface{})
 	_ = json.Unmarshal([]byte(
 		`{"hello": {"id": "Thing:1337", "firstName": "Foo", "lastName": "bar"}}`),
 		&source,
@@ -2672,7 +2671,8 @@ func TestExecutor_plansWithManyDeepDependencies(t *testing.T) {
 												"id":      "2",
 												"address": "Cats street",
 											},
-										}}},
+										}},
+									},
 									{
 										ParentType:     "User",
 										InsertionPoint: []string{"user", "parent", "parent", "house", "cats"},
@@ -2683,10 +2683,12 @@ func TestExecutor_plansWithManyDeepDependencies(t *testing.T) {
 												Definition: definitionFactory("String"),
 											},
 										},
-										Queryer: &graphql.MockSuccessQueryer{Value: map[string]interface{}{
-											"node": map[string]interface{}{
-												"id": "3", "name": "kitty",
-											}},
+										Queryer: &graphql.MockSuccessQueryer{
+											Value: map[string]interface{}{
+												"node": map[string]interface{}{
+													"id": "3", "name": "kitty",
+												},
+											},
 										},
 									},
 								},

gateway_test.go

@@ -3,11 +3,16 @@ package gateway
 import (
 	"context"
 	"errors"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
 	"strings"
 	"testing"
 
 	"github.com/nautilus/graphql"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/vektah/gqlparser/v2"
 	"github.com/vektah/gqlparser/v2/ast"
 )
 
@@ -89,7 +94,6 @@ func TestGateway(t *testing.T) {
 		gateway, err := New([]*graphql.RemoteSchema{sources[0]}, func(schema *Gateway) {
 			schema.sources = append(schema.sources, sources[1])
 		})
-
 		if err != nil {
 			t.Error(err.Error())
 			return
@@ -286,7 +290,6 @@ func TestGateway(t *testing.T) {
 
 		// build a query plan that the executor will follow
 		response, err := gateway.Execute(reqCtx, plan)
-
 		if err != nil {
 			t.Errorf("Encountered error executing plan: %s", err.Error())
 			return
@@ -331,7 +334,6 @@ func TestGateway(t *testing.T) {
 					RootStep: &QueryPlanStep{
 						Then: []*QueryPlanStep{
 							{
-
 								// this is equivalent to
 								// query { allUsers }
 								ParentType:     typeNameQuery,
@@ -554,7 +556,6 @@ func TestGatewayExecuteRespectsOperationName(t *testing.T) {
 				RootStep: &QueryPlanStep{
 					Then: []*QueryPlanStep{
 						{
-
 							// this is equivalent to
 							// query { allUsers }
 							ParentType:     typeNameQuery,
@@ -594,7 +595,6 @@ func TestGatewayExecuteRespectsOperationName(t *testing.T) {
 				RootStep: &QueryPlanStep{
 					Then: []*QueryPlanStep{
 						{
-
 							// this is equivalent to
 							// query { allUsers }
 							ParentType:     typeNameQuery,
@@ -684,3 +684,72 @@ func TestFieldURLs_concat(t *testing.T) {
 	}
 	assert.Equal(t, []string{"url2"}, urlLocations3)
 }
+
+// Verifies fix for https://github.com/nautilus/gateway/issues/199
+func TestIncludeIfVariable(t *testing.T) {
+	t.Parallel()
+	schema, err := graphql.LoadSchema(`
+type Query {
+	hello: String
+	user: User
+}
+
+type User {
+	firstName: String
+}
+`)
+	require.NoError(t, err)
+	queryerFactory := QueryerFactory(func(ctx *PlanningContext, url string) graphql.Queryer {
+		return graphql.QueryerFunc(func(input *graphql.QueryInput) (interface{}, error) {
+			query := gqlparser.MustLoadQuery(schema, input.Query)
+			var operation ast.OperationDefinition
+			if assert.Len(t, query.Operations, 1) {
+				operation = *query.Operations[0]
+			}
+			assert.Len(t, operation.VariableDefinitions, 1)
+			assert.NotNil(t, operation.VariableDefinitions.ForName("returnUser"))
+			assert.Equal(t, map[string]interface{}{
+				"returnUser": true,
+			}, input.Variables)
+			return map[string]interface{}{
+				"hello": "world",
+				"user": map[string]interface{}{
+					"firstName": "foo",
+				},
+			}, nil
+		})
+	})
+	gateway, err := New([]*graphql.RemoteSchema{
+		{Schema: schema, URL: "url1"},
+	}, WithQueryerFactory(&queryerFactory))
+	require.NoError(t, err)
+
+	req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(fmt.Sprintf(`
+		{
+			"query": %q,
+			"variables": {
+				"returnUser": true
+			}
+		}
+	`, `
+		query($returnUser: Boolean!) {
+			hello
+			user @include(if: $returnUser) {
+				firstName
+			}
+		}
+	`)))
+	resp := httptest.NewRecorder()
+	gateway.GraphQLHandler(resp, req)
+	assert.Equal(t, http.StatusOK, resp.Code)
+	assert.JSONEq(t, `
+		{
+			"data": {
+				"hello": "world",
+				"user": {
+					"firstName": "foo"
+				}
+			}
+		}
+	`, resp.Body.String())
+}

plan.go

@@ -450,6 +450,11 @@ func (p *MinQueriesPlanner) extractSelection(ctx *PlanningContext, config *extra
 			for _, variable := range graphql.ExtractVariables(selection.Arguments) {
 				config.step.Variables.Add(variable)
 			}
+			for _, directive := range selection.Directives {
+				for _, variable := range graphql.ExtractVariables(directive.Arguments) {
+					config.step.Variables.Add(variable)
+				}
+			}
 
 			// add it to the list
 			finalSelection = append(finalSelection, selection)
@@ -524,7 +529,6 @@ func (p *MinQueriesPlanner) extractSelection(ctx *PlanningContext, config *extra
 				selection:  selection.SelectionSet,
 				wrapper:    newWrapper,
 			})
-
 			if err != nil {
 				return nil, err
 			}
@@ -541,7 +545,6 @@ func (p *MinQueriesPlanner) extractSelection(ctx *PlanningContext, config *extra
 }
 
 func (p *MinQueriesPlanner) wrapSelectionSet(ctx *PlanningContext, config *extractSelectionConfig, locationFragments map[string]ast.FragmentDefinitionList, location string, selectionSet ast.SelectionSet) (ast.SelectionSet, error) {
-
 	ctx.Gateway.logger.Debug("wrapping selection", config.wrapper)
 
 	// pointers required to nest the
@@ -634,7 +637,6 @@ func (p *MinQueriesPlanner) selectLocation(possibleLocations []string, config *e
 }
 
 func (p *MinQueriesPlanner) groupSelectionSet(ctx *PlanningContext, config *extractSelectionConfig) (map[string]ast.SelectionSet, map[string]ast.FragmentDefinitionList, error) {
-
 	locationFields := map[string]ast.SelectionSet{}
 	locationFragments := map[string]ast.FragmentDefinitionList{}