koron-go/gqlcost

gqlcost provides cost analysis validation rule for graphql-go/graphql. This is a port of pa-bru/graphql-cost-analysis.

gqlcost supports only cost map, and not support @cost directive for now. Because graphql-go/graphql's graphql.Schema, Object and Field don't have spaces to store values for directives.

Getting started

Put this codes to your project.

It adds a cost analysis validation rule to graphql.SpecifiedRules Currently, graphql-go/graphql doesn't have any methods to customize validation rules exclude modifing graphql.SpecifiedRules.

import "github.com/koron-go/gqlcost"

func init() {
    gqlcost.AddCostAnalysisRule(gqlcost.AnalysisOptions{
        // FIXME: modify maximum cost as you need.
        MaximumCost: 1000,
        // CostMap defines cost for types and fields.
        CostMap: gqlcost.CostMap{
            // FIXME: modify CostMap as you need.
            "Query": gqlcost.TypeCost{
                // cost for "Query" type.
                Cost: &gqlcost.Cost{Complexity: 1},
                // cost for fields of "Query" type.
                Fields: gqlcost.FieldsCost{
                    "todoList": gqlcost.Cost{
                        UseMultipliers: true,
                        Complexity:     2,
                        Multipliers:    []string{"limit"},
                    },
                    // TODO: add other fields.
                },
            },
            // TODO: add other costs for types by using `TypeCost`
        },
    })
}