fix: add ability to exclude introspection queries from complexity limits (#1342)

Allow external users to configure if they want to skip intospection
querues in the complexity limits.

Follow-up in Cosmo: wundergraph/cosmo#2296

Author: ysmolski

execution/graphql/complexity.go

@@ -9,7 +9,6 @@ import (
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/ast"
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/astparser"
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/engine/resolve"
-	"github.com/wundergraph/graphql-go-tools/v2/pkg/middleware/operation_complexity"
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/operationreport"
 )
 
@@ -67,23 +66,6 @@ func (r *Request) SetHeader(header http.Header) {
 	r.request.Header = header
 }
 
-func (r *Request) CalculateComplexity(complexityCalculator ComplexityCalculator, schema *Schema) (ComplexityResult, error) {
-	if schema == nil {
-		return ComplexityResult{}, ErrNilSchema
-	}
-
-	report := r.parseQueryOnce()
-	if report.HasErrors() {
-		return complexityResult(
-			operation_complexity.OperationStats{},
-			[]operation_complexity.RootFieldStats{},
-			report,
-		)
-	}
-
-	return complexityCalculator.Calculate(&r.document, &schema.document)
-}
-
 func (r *Request) Document() *ast.Document {
 	return &r.document
 }

execution/graphql/request.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
+	"github.com/wundergraph/graphql-go-tools/v2/pkg/middleware/operation_complexity"
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/starwars"
 )
 
@@ -88,64 +89,69 @@ func TestRequest_parseQueryOnce(t *testing.T) {
 }
 
 func TestRequest_CalculateComplexity(t *testing.T) {
-	t.Run("should return error when schema is nil", func(t *testing.T) {
-		request := Request{}
-		result, err := request.CalculateComplexity(DefaultComplexityCalculator, nil)
-		assert.Error(t, err)
-		assert.Equal(t, ErrNilSchema, err)
-		assert.Equal(t, 0, result.NodeCount, "unexpected node count")
-		assert.Equal(t, 0, result.Complexity, "unexpected complexity")
-		assert.Equal(t, 0, result.Depth, "unexpected depth")
-		assert.Nil(t, result.PerRootField, "per root field results is not nil")
-	})
-
 	t.Run("should successfully calculate the complexity of request", func(t *testing.T) {
 		schema := StarwarsSchema(t)
-
 		request := StarwarsRequestForQuery(t, starwars.FileSimpleHeroQuery)
-		result, err := request.CalculateComplexity(DefaultComplexityCalculator, schema)
-		assert.NoError(t, err)
-		assert.Equal(t, 1, result.NodeCount, "unexpected node count")
-		assert.Equal(t, 1, result.Complexity, "unexpected complexity")
-		assert.Equal(t, 2, result.Depth, "unexpected depth")
-		assert.Equal(t, []FieldComplexityResult{
+
+		report := request.parseQueryOnce()
+		assert.False(t, report.HasErrors())
+
+		estimator := operation_complexity.NewOperationComplexityEstimator(false)
+		global, rootFields := estimator.Do(request.Document(), schema.Document(), &report)
+		assert.False(t, report.HasErrors())
+
+		assert.Equal(t, 1, global.NodeCount, "unexpected node count")
+		assert.Equal(t, 1, global.Complexity, "unexpected complexity")
+		assert.Equal(t, 2, global.Depth, "unexpected depth")
+		assert.Equal(t, []operation_complexity.RootFieldStats{
 			{
-				TypeName:   "Query",
-				FieldName:  "hero",
-				Alias:      "",
-				NodeCount:  1,
-				Complexity: 1,
-				Depth:      1,
+				TypeName:  "Query",
+				FieldName: "hero",
+				Alias:     "",
+				Stats: operation_complexity.OperationStats{
+					NodeCount:  1,
+					Complexity: 1,
+					Depth:      1,
+				},
 			},
-		}, result.PerRootField, "unexpected per root field results")
+		}, rootFields, "unexpected per root field results")
 	})
 
 	t.Run("should successfully calculate the complexity of request with multiple query fields", func(t *testing.T) {
 		schema := StarwarsSchema(t)
-
 		request := StarwarsRequestForQuery(t, starwars.FileHeroWithAliasesQuery)
-		result, err := request.CalculateComplexity(DefaultComplexityCalculator, schema)
-		assert.NoError(t, err)
-		assert.Equal(t, 2, result.NodeCount, "unexpected node count")
-		assert.Equal(t, 2, result.Complexity, "unexpected complexity")
-		assert.Equal(t, 2, result.Depth, "unexpected depth")
-		assert.Equal(t, []FieldComplexityResult{
+
+		report := request.parseQueryOnce()
+		assert.False(t, report.HasErrors())
+
+		estimator := operation_complexity.NewOperationComplexityEstimator(false)
+		global, rootFields := estimator.Do(request.Document(), schema.Document(), &report)
+		assert.False(t, report.HasErrors())
+
+		assert.Equal(t, 2, global.NodeCount, "unexpected node count")
+		assert.Equal(t, 2, global.Complexity, "unexpected complexity")
+		assert.Equal(t, 2, global.Depth, "unexpected depth")
+		assert.Equal(t, []operation_complexity.RootFieldStats{
 			{
-				TypeName:   "Query",
-				FieldName:  "hero",
-				Alias:      "empireHero",
-				NodeCount:  1,
-				Complexity: 1,
-				Depth:      1,
+				TypeName:  "Query",
+				FieldName: "hero",
+				Alias:     "empireHero",
+				Stats: operation_complexity.OperationStats{
+					NodeCount:  1,
+					Complexity: 1,
+					Depth:      1,
+				},
 			},
 			{
-				TypeName:   "Query",
-				FieldName:  "hero",
-				Alias:      "jediHero",
-				NodeCount:  1,
-				Complexity: 1,
-				Depth:      1,
-			}}, result.PerRootField, "unexpected per root field results")
+				TypeName:  "Query",
+				FieldName: "hero",
+				Alias:     "jediHero",
+				Stats: operation_complexity.OperationStats{
+					NodeCount:  1,
+					Complexity: 1,
+					Depth:      1,
+				},
+			}}, rootFields, "unexpected per root field results")
 	})
 }
 

execution/graphql/request_test.go

@@ -52,22 +52,21 @@ var (
 )
 
 const (
-	skipIntrospection = true
-	__schemaLiteral   = "__schema"
-	__typeLiteral     = "__type"
+	__schemaLiteral = "__schema"
+	__typeLiteral   = "__type"
 )
 
 type OperationComplexityEstimator struct {
 	walker  *astvisitor.Walker
 	visitor *complexityVisitor
 }
 
-func NewOperationComplexityEstimator() *OperationComplexityEstimator {
-
+func NewOperationComplexityEstimator(skipIntrospection bool) *OperationComplexityEstimator {
 	walker := astvisitor.NewWalker(48)
 	visitor := &complexityVisitor{
-		Walker:      &walker,
-		multipliers: make([]multiplier, 0, 16),
+		Walker:            &walker,
+		multipliers:       make([]multiplier, 0, 16),
+		skipIntrospection: skipIntrospection,
 	}
 
 	walker.RegisterEnterDocumentVisitor(visitor)
@@ -116,8 +115,9 @@ func (n *OperationComplexityEstimator) Do(operation, definition *ast.Document, r
 	return globalResult, n.visitor.calculatedRootFieldStats
 }
 
+// Deprecated: use NewOperationComplexityEstimator.
 func CalculateOperationComplexity(operation, definition *ast.Document, report *operationreport.Report) (OperationStats, []RootFieldStats) {
-	estimator := NewOperationComplexityEstimator()
+	estimator := NewOperationComplexityEstimator(false)
 	return estimator.Do(operation, definition, report)
 }
 
@@ -141,6 +141,9 @@ type complexityVisitor struct {
 	currentRootFieldSelectionSetDepth    int
 
 	calculatedRootFieldStats []RootFieldStats
+
+	// Enforces to ignore introspection queries in calculations.
+	skipIntrospection bool
 }
 
 type multiplier struct {
@@ -202,7 +205,7 @@ func (c *complexityVisitor) EnterField(ref int) {
 	}
 
 	typeName, fieldName, alias := c.extractFieldRelatedNames(ref, definition)
-	if skipIntrospection && (fieldName == __schemaLiteral || fieldName == __typeLiteral) {
+	if c.skipIntrospection && (fieldName == __schemaLiteral || fieldName == __typeLiteral) {
 		c.SkipNode()
 		return
 	}

v2/pkg/middleware/operation_complexity/operation_complexity.go

@@ -467,6 +467,26 @@ func TestCalculateOperationComplexity(t *testing.T) {
 	})
 	t.Run("introspection query", func(t *testing.T) {
 		run(t, testDefinition, introspectionQuery,
+			OperationStats{
+				NodeCount:  59,
+				Complexity: 59,
+				Depth:      13,
+			},
+			[]RootFieldStats{
+				{
+					TypeName:  "Query",
+					FieldName: "__schema",
+					Stats: OperationStats{
+						NodeCount:  59,
+						Complexity: 59,
+						Depth:      12,
+					},
+				},
+			},
+		)
+	})
+	t.Run("introspection query with skip", func(t *testing.T) {
+		runSkipIntrospection(t, testDefinition, introspectionQuery,
 			OperationStats{
 				NodeCount:  0,
 				Complexity: 0,
@@ -477,35 +497,43 @@ func TestCalculateOperationComplexity(t *testing.T) {
 	})
 }
 
-var run = func(t *testing.T, definition, operation string, expectedGlobalComplexityResult OperationStats, expectedFieldsComplexityResult []RootFieldStats) {
+func runConfig(t *testing.T, definition, operation string, expectedGlobalComplexityResult OperationStats, expectedFieldsComplexityResult []RootFieldStats, skipIntrospection bool) {
 	def := unsafeparser.ParseGraphqlDocumentString(definition)
 	op := unsafeparser.ParseGraphqlDocumentString(operation)
 	report := operationreport.Report{}
 
 	astnormalization.NormalizeOperation(&op, &def, &report)
 
-	actualGlobalComplexityResult, actualFieldsComplexityResult := CalculateOperationComplexity(&op, &def, &report)
-	if report.HasErrors() {
-		require.NoError(t, report)
-	}
+	estimator := NewOperationComplexityEstimator(skipIntrospection)
+	actualGlobalComplexityResult, actualFieldsComplexityResult := estimator.Do(&op, &def, &report)
+	require.False(t, report.HasErrors())
 
 	assert.Equal(t, expectedGlobalComplexityResult.NodeCount, actualGlobalComplexityResult.NodeCount, "unexpected global node count")
 	assert.Equal(t, expectedGlobalComplexityResult.Complexity, actualGlobalComplexityResult.Complexity, "unexpected global complexity")
 	assert.Equal(t, expectedGlobalComplexityResult.Depth, actualGlobalComplexityResult.Depth, "unexpected global depth")
 	assert.Equal(t, expectedFieldsComplexityResult, actualFieldsComplexityResult, "unexpected fields complexity result")
 }
 
+func run(t *testing.T, definition, operation string, expectedGlobalComplexityResult OperationStats, expectedFieldsComplexityResult []RootFieldStats) {
+	runConfig(t, definition, operation, expectedGlobalComplexityResult, expectedFieldsComplexityResult, false)
+}
+
+func runSkipIntrospection(t *testing.T, definition, operation string, expectedGlobalComplexityResult OperationStats, expectedFieldsComplexityResult []RootFieldStats) {
+	runConfig(t, definition, operation, expectedGlobalComplexityResult, expectedFieldsComplexityResult, true)
+}
+
 func BenchmarkEstimateComplexity(b *testing.B) {
 	def := unsafeparser.ParseGraphqlDocumentString(testDefinition)
 	op := unsafeparser.ParseGraphqlDocumentString(complexQuery)
 
-	estimator := NewOperationComplexityEstimator()
-	report := operationreport.Report{}
-
 	b.ResetTimer()
 	b.ReportAllocs()
 
 	for i := 0; i < b.N; i++ {
+		// We use NewOperationComplexityEstimator for every operation in production, thus
+		// we want it in the benchmarking loop.
+		estimator := NewOperationComplexityEstimator(false)
+		report := operationreport.Report{}
 		globalComplexityResult, _ := estimator.Do(&op, &def, &report)
 		if report.HasErrors() {
 			b.Fatal(report)