fix: calculate costs for abstract fields correctly

router-tests/go.mod

@@ -31,7 +31,7 @@ require (
 	github.com/wundergraph/cosmo/router v0.0.0-20260330183556-dc4388d100a4
 	github.com/wundergraph/cosmo/router-plugin v0.0.0-20250808194725-de123ba1c65e
 	github.com/wundergraph/cosmo/speedtrap v0.0.0-00010101000000-000000000000
-	github.com/wundergraph/graphql-go-tools/v2 v2.4.2
+	github.com/wundergraph/graphql-go-tools/v2 v2.4.4
 	go.opentelemetry.io/otel v1.43.0
 	go.opentelemetry.io/otel/sdk v1.43.0
 	go.opentelemetry.io/otel/sdk/metric v1.43.0

router-tests/go.sum

@@ -381,8 +381,8 @@ github.com/wundergraph/astjson v1.1.0 h1:xORDosrZ87zQFJwNGe/HIHXqzpdHOFmqWgykCLV
 github.com/wundergraph/astjson v1.1.0/go.mod h1:h12D/dxxnedtLzsKyBLK7/Oe4TAoGpRVC9nDpDrZSWw=
 github.com/wundergraph/go-arena v1.1.0 h1:9+wSRkJAkA2vbYHp6s8tEGhPViRGQNGXqPHT0QzhdIc=
 github.com/wundergraph/go-arena v1.1.0/go.mod h1:ROOysEHWJjLQ8FSfNxZCziagb7Qw2nXY3/vgKRh7eWw=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.2 h1:aNBJ9l8QQY7Yo4pqmny91GuLAPGAySDKW2ivUhaO9eo=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.2/go.mod h1:7ljNHLrBOoOszCk4ir4Z+O6Yrf+vwBBmxjwqM3imVgA=
+github.com/wundergraph/graphql-go-tools/v2 v2.4.4 h1:VCvS9bku4ie7+St3+H5SNuVz6dtQiDKujqQ439yrMBM=
+github.com/wundergraph/graphql-go-tools/v2 v2.4.4/go.mod h1:7ljNHLrBOoOszCk4ir4Z+O6Yrf+vwBBmxjwqM3imVgA=
 github.com/xrash/smetrics v0.0.0-20250705151800-55b8f293f342 h1:FnBeRrxr7OU4VvAzt5X7s6266i6cSVkkFPS0TuXWbIg=
 github.com/xrash/smetrics v0.0.0-20250705151800-55b8f293f342/go.mod h1:Ohn+xnUBiLI6FVj/9LpzZWtj1/D6lUovWYBkxHVV3aM=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=

router-tests/protocol/mcp_test.go

@@ -138,7 +138,7 @@ func TestMCP(t *testing.T) {
 					Description: "This is a GraphQL query that retrieves a list of employees.",
 					InputSchema: mcp.ToolInputSchema{
 						Type:       "object",
-						Properties: map[string]interface{}{"criteria": map[string]interface{}{"additionalProperties": false, "description": "Allows to filter employees by their details.", "nullable": false, "properties": map[string]interface{}{"hasPets": map[string]interface{}{"nullable": true, "type": "boolean"}, "nationality": map[string]interface{}{"enum": []interface{}{"AMERICAN", "DUTCH", "ENGLISH", "GERMAN", "INDIAN", "SPANISH", "UKRAINIAN"}, "nullable": true, "type": "string"}, "nested": map[string]interface{}{"additionalProperties": false, "nullable": true, "properties": map[string]interface{}{"hasChildren": map[string]interface{}{"nullable": true, "type": "boolean"}, "maritalStatus": map[string]interface{}{"enum": []interface{}{"ENGAGED", "MARRIED"}, "nullable": true, "type": "string"}}, "type": "object"}}, "type": "object"}},
+						Properties: map[string]interface{}{"criteria": map[string]interface{}{"additionalProperties": false, "description": "Allows to filter employees by their details.", "properties": map[string]interface{}{"hasPets": map[string]interface{}{"type": []interface{}{"boolean", "null"}}, "nationality": map[string]interface{}{"enum": []interface{}{"AMERICAN", "DUTCH", "ENGLISH", "GERMAN", "INDIAN", "SPANISH", "UKRAINIAN", nil}, "type": []interface{}{"string", "null"}}, "nested": map[string]interface{}{"additionalProperties": false, "properties": map[string]interface{}{"hasChildren": map[string]interface{}{"type": []interface{}{"boolean", "null"}}, "maritalStatus": map[string]interface{}{"enum": []interface{}{"ENGAGED", "MARRIED", nil}, "type": []interface{}{"string", "null"}}}, "type": []interface{}{"object", "null"}}}, "type": "object"}},
 						Required:   []string(nil)},
 					RawInputSchema: json.RawMessage(nil),
 					Annotations: mcp.ToolAnnotation{
@@ -298,7 +298,7 @@ Description: This is a GraphQL query that retrieves a list of employees.
 
 Input Schema:
 ` + bt + `json
-{"additionalProperties":false,"description":"This is a GraphQL query that retrieves a list of employees.","nullable":true,"properties":{"criteria":{"additionalProperties":false,"description":"Allows to filter employees by their details.","nullable":false,"properties":{"hasPets":{"nullable":true,"type":"boolean"},"nationality":{"enum":["AMERICAN","DUTCH","ENGLISH","GERMAN","INDIAN","SPANISH","UKRAINIAN"],"nullable":true,"type":"string"},"nested":{"additionalProperties":false,"nullable":true,"properties":{"hasChildren":{"nullable":true,"type":"boolean"},"maritalStatus":{"enum":["ENGAGED","MARRIED"],"nullable":true,"type":"string"}},"type":"object"}},"type":"object"}},"type":"object"}
+{"additionalProperties":false,"description":"This is a GraphQL query that retrieves a list of employees.","properties":{"criteria":{"additionalProperties":false,"description":"Allows to filter employees by their details.","properties":{"hasPets":{"type":["boolean","null"]},"nationality":{"enum":["AMERICAN","DUTCH","ENGLISH","GERMAN","INDIAN","SPANISH","UKRAINIAN",null],"type":["string","null"]},"nested":{"additionalProperties":false,"properties":{"hasChildren":{"type":["boolean","null"]},"maritalStatus":{"enum":["ENGAGED","MARRIED",null],"type":["string","null"]}},"type":["object","null"]}},"type":"object"}},"type":"object"}
 ` + bt + `
 
 GraphQL Query:

router-tests/security/costs_test.go

@@ -287,7 +287,7 @@ func TestOperationCost(t *testing.T) {
 				require.Equal(t, "230", estimated)
 
 				actual := res.Response.Header.Get(core.CostActualHeader)
-				require.Equal(t, "46", actual) // (7/3 + 13) * 3
+				require.Equal(t, "24", actual) // 3 * (5.67 + 1*7/3)
 
 				// Query 2: only employees-subgraph fields — Cosmo @cost(weight: 5) from employees applies
 				res2 := xEnv.MakeGraphQLRequestOK(testenv.GraphQLRequest{
@@ -300,7 +300,7 @@ func TestOperationCost(t *testing.T) {
 				require.Equal(t, "150", estimated2)
 
 				actual2 := res2.Response.Header.Get(core.CostActualHeader)
-				require.Equal(t, "22", actual2)
+				require.Equal(t, "14", actual2)
 			})
 		})
 

router/core/graphql_handler.go

@@ -227,13 +227,13 @@ func (h *GraphQLHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				pw.reqCtx = reqCtx
 			}
 			if h.enableCostResponseHeaders && reqCtx.operation.costEstimatedSet {
-				// actualListSizes is populated by the resolver after resolution completes,
+				// ArrayStats is populated by the resolver after resolution completes,
 				// and we need to set headers before actual write happens in the same resolver.
-				pw.costHeaderSetter = func(actualListSizes map[string]int) {
+				pw.costHeaderSetter = func(typeStats map[string]resolve.TypeNameStats) {
 					pw.writer.Header().Set(CostEstimatedHeader, strconv.Itoa(reqCtx.operation.costEstimated))
-					if actualListSizes != nil {
+					if typeStats != nil {
 						if costCalc := reqCtx.operation.preparedPlan.preparedPlan.GetCostCalculator(); costCalc != nil {
-							actual := costCalc.ActualCost(resolveCtx.VariablesView(), actualListSizes)
+							actual := costCalc.ActualCost(resolveCtx.VariablesView(), typeStats)
 							reqCtx.operation.costActual = actual
 							reqCtx.operation.costActualSet = true
 							pw.writer.Header().Set(CostActualHeader, strconv.Itoa(actual))
@@ -252,10 +252,10 @@ func (h *GraphQLHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 
 		// Compute actual cost for metrics/telemetry if not already set by the header callback
-		if !reqCtx.operation.costActualSet && resolveCtx.ActualListSizes != nil &&
+		if !reqCtx.operation.costActualSet && resolveCtx.TypeNameStats != nil &&
 			reqCtx.operation.preparedPlan != nil && reqCtx.operation.preparedPlan.preparedPlan != nil {
 			if costCalc := reqCtx.operation.preparedPlan.preparedPlan.GetCostCalculator(); costCalc != nil {
-				reqCtx.operation.costActual = costCalc.ActualCost(resolveCtx.VariablesView(), resolveCtx.ActualListSizes)
+				reqCtx.operation.costActual = costCalc.ActualCost(resolveCtx.VariablesView(), resolveCtx.TypeNameStats)
 				reqCtx.operation.costActualSet = true
 			}
 		}

router/core/header_rule_engine.go

@@ -16,6 +16,10 @@ import (
 	"github.com/cespare/xxhash/v2"
 	"github.com/expr-lang/expr/vm"
 	cachedirective "github.com/pquerna/cachecontrol/cacheobject"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+	"go.uber.org/zap"
+
 	nodev1 "github.com/wundergraph/cosmo/router/gen/proto/wg/cosmo/node/v1"
 	"github.com/wundergraph/cosmo/router/internal/expr"
 	"github.com/wundergraph/cosmo/router/internal/headers"
@@ -25,9 +29,6 @@ import (
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/ast"
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/engine/datasource/graphql_datasource"
 	"github.com/wundergraph/graphql-go-tools/v2/pkg/engine/resolve"
-	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/trace"
-	"go.uber.org/zap"
 )
 
 var (
@@ -103,7 +104,7 @@ type headerPropagationWriter struct {
 	routerHeaderPropagation   *HeaderPropagation
 	reqCtx                    *requestContext
 	didApplyRouterRespHeaders bool
-	costHeaderSetter          func(actualListSizes map[string]int)
+	costHeaderSetter          func(typeStats map[string]resolve.TypeNameStats)
 	didSetCostHeaders         bool
 }
 
@@ -137,7 +138,7 @@ func (h *headerPropagationWriter) Write(p []byte) (n int, err error) {
 	}
 	if h.costHeaderSetter != nil && !h.didSetCostHeaders {
 		h.didSetCostHeaders = true
-		h.costHeaderSetter(h.resolveCtx.ActualListSizes)
+		h.costHeaderSetter(h.resolveCtx.TypeNameStats)
 	}
 	return h.writer.Write(p)
 }

router/go.mod

@@ -31,7 +31,7 @@ require (
 	github.com/tidwall/gjson v1.18.0
 	github.com/tidwall/sjson v1.2.5
 	github.com/twmb/franz-go v1.16.1
-	github.com/wundergraph/graphql-go-tools/v2 v2.4.2
+	github.com/wundergraph/graphql-go-tools/v2 v2.4.4
 	// Do not upgrade, it renames attributes we rely on
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.68.0
 	go.opentelemetry.io/contrib/propagators/b3 v1.43.0

router/go.sum

@@ -333,8 +333,8 @@ github.com/wundergraph/astjson v1.1.0 h1:xORDosrZ87zQFJwNGe/HIHXqzpdHOFmqWgykCLV
 github.com/wundergraph/astjson v1.1.0/go.mod h1:h12D/dxxnedtLzsKyBLK7/Oe4TAoGpRVC9nDpDrZSWw=
 github.com/wundergraph/go-arena v1.1.0 h1:9+wSRkJAkA2vbYHp6s8tEGhPViRGQNGXqPHT0QzhdIc=
 github.com/wundergraph/go-arena v1.1.0/go.mod h1:ROOysEHWJjLQ8FSfNxZCziagb7Qw2nXY3/vgKRh7eWw=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.2 h1:aNBJ9l8QQY7Yo4pqmny91GuLAPGAySDKW2ivUhaO9eo=
-github.com/wundergraph/graphql-go-tools/v2 v2.4.2/go.mod h1:7ljNHLrBOoOszCk4ir4Z+O6Yrf+vwBBmxjwqM3imVgA=
+github.com/wundergraph/graphql-go-tools/v2 v2.4.4 h1:VCvS9bku4ie7+St3+H5SNuVz6dtQiDKujqQ439yrMBM=
+github.com/wundergraph/graphql-go-tools/v2 v2.4.4/go.mod h1:7ljNHLrBOoOszCk4ir4Z+O6Yrf+vwBBmxjwqM3imVgA=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
 github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
 github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=