Refactor trace package

Remove dependency for graphql-go on OpenTracing and OpenTelemetry except
 where those tracers are explicitly configured for use.

README.md

@@ -11,7 +11,7 @@ safe for production use.
 
 - minimal API
 - support for `context.Context`
-- support for the `OpenTracing` standard
+- support for the `OpenTelemetry` and `OpenTracing` standards
 - schema type-checking against resolvers
 - resolvers are matched to the schema based on method sets (can resolve a GraphQL schema with a Go interface or Go struct).
 - handles panics in resolvers
@@ -108,8 +108,7 @@ func (r *helloWorldResolver) Hello(ctx context.Context) (string, error) {
 - `UseFieldResolvers()` specifies whether to use struct field resolvers.
 - `MaxDepth(n int)` specifies the maximum field nesting depth in a query. The default is 0 which disables max depth checking.
 - `MaxParallelism(n int)` specifies the maximum number of resolvers per request allowed to run in parallel. The default is 10.
-- `Tracer(tracer trace.Tracer)` is used to trace queries and fields. It defaults to `trace.OpenTracingTracer`.
-- `ValidationTracer(tracer trace.ValidationTracer)` is used to trace validation errors. It defaults to `trace.NoopValidationTracer`.
+- `Tracer(tracer trace.Tracer)` is used to trace queries and fields. It defaults to `noop.Tracer`.
 - `Logger(logger log.Logger)` is used to log panics during query execution. It defaults to `exec.DefaultLogger`.
 - `PanicHandler(panicHandler errors.PanicHandler)` is used to transform panics into errors during query execution. It defaults to `errors.DefaultPanicHandler`.
 - `DisableIntrospection()` disables introspection queries.
@@ -165,6 +164,47 @@ Which could produce a GraphQL error such as:
 }
 ```
 
+### Tracing
+
+By default the library uses `noop.Tracer`. If you want to change that you can use the OpenTelemetry or the OpenTracing implementations, respectively:
+
+```go
+// OpenTelemetry tracer
+package main
+
+import (
+	"github.com/graph-gophers/graphql-go"
+	"github.com/graph-gophers/graphql-go/example/starwars"
+	otelgraphql "github.com/graph-gophers/graphql-go/trace/otel"
+	"github.com/graph-gophers/graphql-go/trace/tracer"
+)
+// ...
+_, err := graphql.ParseSchema(starwars.Schema, nil, graphql.Tracer(otelgraphql.DefaultTracer()))
+// ...
+```
+Alternatively you can pass an existing trace.Tracer instance:
+```go
+_, err = graphql.ParseSchema(starwars.Schema, nil, graphql.Tracer(&otelgraphql.Tracer{Tracer: otel.Tracer("example")}))
+```
+
+
+```go
+// OpenTracing tracer
+package main
+
+import (
+	"github.com/graph-gophers/graphql-go"
+	"github.com/graph-gophers/graphql-go/example/starwars"
+	"github.com/graph-gophers/graphql-go/trace/opentracing"
+	"github.com/graph-gophers/graphql-go/trace/tracer"
+)
+// ...
+_, err := graphql.ParseSchema(starwars.Schema, nil, graphql.Tracer(opentracing.Tracer{}))
+
+// ...
+```
+
+
 ### [Examples](https://github.com/graph-gophers/graphql-go/wiki/Examples)
 
 ### [Companies that use this library](https://github.com/graph-gophers/graphql-go/wiki/Users)

go.mod

@@ -1,10 +1,9 @@
 module github.com/graph-gophers/graphql-go
 
+go 1.13
+
 require (
-	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/opentracing/opentracing-go v1.2.0
-	go.opentelemetry.io/otel v1.3.0
-	go.opentelemetry.io/otel/trace v1.3.0
+	go.opentelemetry.io/otel v1.6.3
+	go.opentelemetry.io/otel/trace v1.6.3
 )
-
-go 1.13

go.sum

@@ -1,24 +1,27 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
-github.com/go-logr/logr v1.2.1/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
-github.com/go-logr/logr v1.2.2 h1:ahHml/yUpnlb96Rp8HCvtYVPY8ZYpxq3g7UYchIYwbs=
 github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
-github.com/go-logr/stdr v1.2.0/go.mod h1:YkVgnZu1ZjjL7xTxrfm/LLZBfkhTqSR1ydtm6jTKKwI=
+github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
-github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/opentracing/opentracing-go v1.1.0 h1:pWlfV3Bxv7k65HYwkikxat0+s3pV4bsqf19k25Ur8rU=
-github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
+github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
 github.com/opentracing/opentracing-go v1.2.0 h1:uEJPy/1a5RIPAJ0Ov+OIO8OxWu77jEv+1B0VhjKrZUs=
 github.com/opentracing/opentracing-go v1.2.0/go.mod h1:GxEUsuufX4nBwe+T+Wl9TAgYrxe9dPLANfrWvHYVTgc=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
-github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-go.opentelemetry.io/otel v1.3.0 h1:APxLf0eiBwLl+SOXiJJCVYzA1OOJNyAoV8C5RNRyy7Y=
-go.opentelemetry.io/otel v1.3.0/go.mod h1:PWIKzi6JCp7sM0k9yZ43VX+T345uNbAkDKwHVjb2PTs=
-go.opentelemetry.io/otel/trace v1.3.0 h1:doy8Hzb1RJ+I3yFhtDmwNc7tIyw1tNMOIsyPzp1NOGY=
-go.opentelemetry.io/otel/trace v1.3.0/go.mod h1:c/VDhno8888bvQYmbYLqe41/Ldmr/KKunbvWM4/fEjk=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+go.opentelemetry.io/otel v1.6.3 h1:FLOfo8f9JzFVFVyU+MSRJc2HdEAXQgm7pIv2uFKRSZE=
+go.opentelemetry.io/otel v1.6.3/go.mod h1:7BgNga5fNlF/iZjG06hM3yofffp0ofKCDwSXx1GC4dI=
+go.opentelemetry.io/otel/trace v1.6.3 h1:IqN4L+5b0mPNjdXIiZ90Ni4Bl5BRkDQywePLWemd9bc=
+go.opentelemetry.io/otel/trace v1.6.3/go.mod h1:GNJQusJlUgZl9/TQBPKU/Y/ty+0iVB5fjhKeJGZPGFs=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

graphql.go

@@ -16,7 +16,8 @@ import (
 	"github.com/graph-gophers/graphql-go/internal/validation"
 	"github.com/graph-gophers/graphql-go/introspection"
 	"github.com/graph-gophers/graphql-go/log"
-	"github.com/graph-gophers/graphql-go/trace"
+	"github.com/graph-gophers/graphql-go/trace/noop"
+	"github.com/graph-gophers/graphql-go/trace/tracer"
 	"github.com/graph-gophers/graphql-go/types"
 )
 
@@ -27,7 +28,7 @@ func ParseSchema(schemaString string, resolver interface{}, opts ...SchemaOpt) (
 	s := &Schema{
 		schema:         schema.New(),
 		maxParallelism: 10,
-		tracer:         trace.OpenTracingTracer{},
+		tracer:         noop.Tracer{},
 		logger:         &log.DefaultLogger{},
 		panicHandler:   &errors.DefaultPanicHandler{},
 	}
@@ -36,10 +37,10 @@ func ParseSchema(schemaString string, resolver interface{}, opts ...SchemaOpt) (
 	}
 
 	if s.validationTracer == nil {
-		if tracer, ok := s.tracer.(trace.ValidationTracerContext); ok {
-			s.validationTracer = tracer
+		if t, ok := s.tracer.(tracer.ValidationTracer); ok {
+			s.validationTracer = t
 		} else {
-			s.validationTracer = &validationBridgingTracer{tracer: trace.NoopValidationTracer{}}
+			s.validationTracer = &validationBridgingTracer{tracer: tracer.LegacyNoopValidationTracer{}} //nolint:staticcheck
 		}
 	}
 
@@ -75,8 +76,8 @@ type Schema struct {
 
 	maxDepth                 int
 	maxParallelism           int
-	tracer                   trace.Tracer
-	validationTracer         trace.ValidationTracerContext
+	tracer                   tracer.Tracer
+	validationTracer         tracer.ValidationTracer
 	logger                   log.Logger
 	panicHandler             errors.PanicHandler
 	useStringDescriptions    bool
@@ -122,16 +123,16 @@ func MaxParallelism(n int) SchemaOpt {
 	}
 }
 
-// Tracer is used to trace queries and fields. It defaults to trace.OpenTracingTracer.
-func Tracer(tracer trace.Tracer) SchemaOpt {
+// Tracer is used to trace queries and fields. It defaults to tracer.Noop.
+func Tracer(tracer tracer.Tracer) SchemaOpt {
 	return func(s *Schema) {
 		s.tracer = tracer
 	}
 }
 
-// ValidationTracer is used to trace validation errors. It defaults to trace.NoopValidationTracer.
-// Deprecated: context is needed to support tracing correctly. Use a Tracer which implements trace.ValidationTracerContext.
-func ValidationTracer(tracer trace.ValidationTracer) SchemaOpt { //nolint:staticcheck
+// ValidationTracer is used to trace validation errors. It defaults to tracer.LegacyNoopValidationTracer.
+// Deprecated: context is needed to support tracing correctly. Use a Tracer which implements tracer.ValidationTracer.
+func ValidationTracer(tracer tracer.LegacyValidationTracer) SchemaOpt { //nolint:staticcheck
 	return func(s *Schema) {
 		s.validationTracer = &validationBridgingTracer{tracer: tracer}
 	}
@@ -296,10 +297,10 @@ func (s *Schema) validateSchema() error {
 }
 
 type validationBridgingTracer struct {
-	tracer trace.ValidationTracer //nolint:staticcheck
+	tracer tracer.LegacyValidationTracer //nolint:staticcheck
 }
 
-func (t *validationBridgingTracer) TraceValidation(context.Context) trace.TraceValidationFinishFunc {
+func (t *validationBridgingTracer) TraceValidation(context.Context) func([]*errors.QueryError) {
 	return t.tracer.TraceValidation()
 }
 

graphql_test.go

@@ -13,7 +13,7 @@ import (
 	"github.com/graph-gophers/graphql-go/example/starwars"
 	"github.com/graph-gophers/graphql-go/gqltesting"
 	"github.com/graph-gophers/graphql-go/introspection"
-	"github.com/graph-gophers/graphql-go/trace"
+	"github.com/graph-gophers/graphql-go/trace/tracer"
 )
 
 type helloWorldResolver1 struct{}
@@ -4053,7 +4053,7 @@ type queryTrace struct {
 	errors    []*gqlerrors.QueryError
 }
 
-func (t *testTracer) TraceField(ctx context.Context, label, typeName, fieldName string, trivial bool, args map[string]interface{}) (context.Context, trace.TraceFieldFinishFunc) {
+func (t *testTracer) TraceField(ctx context.Context, label, typeName, fieldName string, trivial bool, args map[string]interface{}) (context.Context, func(*gqlerrors.QueryError)) {
 	return ctx, func(qe *gqlerrors.QueryError) {
 		t.mu.Lock()
 		defer t.mu.Unlock()
@@ -4071,7 +4071,7 @@ func (t *testTracer) TraceField(ctx context.Context, label, typeName, fieldName
 	}
 }
 
-func (t *testTracer) TraceQuery(ctx context.Context, document string, opName string, vars map[string]interface{}, varTypes map[string]*introspection.Type) (context.Context, trace.TraceQueryFinishFunc) {
+func (t *testTracer) TraceQuery(ctx context.Context, document string, opName string, vars map[string]interface{}, varTypes map[string]*introspection.Type) (context.Context, func([]*gqlerrors.QueryError)) {
 	return ctx, func(qe []*gqlerrors.QueryError) {
 		t.mu.Lock()
 		defer t.mu.Unlock()
@@ -4088,14 +4088,14 @@ func (t *testTracer) TraceQuery(ctx context.Context, document string, opName str
 	}
 }
 
-var _ trace.Tracer = (*testTracer)(nil)
+var _ tracer.Tracer = (*testTracer)(nil)
 
 func TestTracer(t *testing.T) {
 	t.Parallel()
 
-	tracer := &testTracer{mu: &sync.Mutex{}}
+	tt := &testTracer{mu: &sync.Mutex{}}
 
-	schema, err := graphql.ParseSchema(starwars.Schema, &starwars.Resolver{}, graphql.Tracer(tracer))
+	schema, err := graphql.ParseSchema(starwars.Schema, &starwars.Resolver{}, graphql.Tracer(tt))
 	if err != nil {
 		t.Fatalf("graphql.ParseSchema: %s", err)
 	}
@@ -4116,14 +4116,14 @@ func TestTracer(t *testing.T) {
 
 	_ = schema.Exec(ctx, doc, opName, variables)
 
-	tracer.mu.Lock()
-	defer tracer.mu.Unlock()
+	tt.mu.Lock()
+	defer tt.mu.Unlock()
 
-	if len(tracer.queries) != 1 {
-		t.Fatalf("expected one query trace, but got %d: %#v", len(tracer.queries), tracer.queries)
+	if len(tt.queries) != 1 {
+		t.Fatalf("expected one query trace, but got %d: %#v", len(tt.queries), tt.queries)
 	}
 
-	qt := tracer.queries[0]
+	qt := tt.queries[0]
 	if qt.document != doc {
 		t.Errorf("mismatched query trace document:\nwant: %q\ngot : %q", doc, qt.document)
 	}
@@ -4137,7 +4137,7 @@ func TestTracer(t *testing.T) {
 		{fieldName: "name", typeName: "Human"},
 	}
 
-	checkFieldTraces(t, expectedFieldTraces, tracer.fields)
+	checkFieldTraces(t, expectedFieldTraces, tt.fields)
 }
 
 func checkFieldTraces(t *testing.T, want, have []fieldTrace) {

internal/exec/exec.go

@@ -14,14 +14,14 @@ import (
 	"github.com/graph-gophers/graphql-go/internal/exec/selected"
 	"github.com/graph-gophers/graphql-go/internal/query"
 	"github.com/graph-gophers/graphql-go/log"
-	"github.com/graph-gophers/graphql-go/trace"
+	"github.com/graph-gophers/graphql-go/trace/tracer"
 	"github.com/graph-gophers/graphql-go/types"
 )
 
 type Request struct {
 	selected.Request
 	Limiter                  chan struct{}
-	Tracer                   trace.Tracer
+	Tracer                   tracer.Tracer
 	Logger                   log.Logger
 	PanicHandler             errors.PanicHandler
 	SubscribeResolverTimeout time.Duration

trace/noop/trace.go

@@ -0,0 +1,24 @@
+// Package noop defines a no-op tracer implementation.
+package noop
+
+import (
+	"context"
+
+	"github.com/graph-gophers/graphql-go/errors"
+	"github.com/graph-gophers/graphql-go/introspection"
+)
+
+// Tracer is a no-op tracer that does nothing.
+type Tracer struct{}
+
+func (Tracer) TraceQuery(ctx context.Context, queryString string, operationName string, variables map[string]interface{}, varTypes map[string]*introspection.Type) (context.Context, func([]*errors.QueryError)) {
+	return ctx, func(errs []*errors.QueryError) {}
+}
+
+func (Tracer) TraceField(ctx context.Context, label, typeName, fieldName string, trivial bool, args map[string]interface{}) (context.Context, func(*errors.QueryError)) {
+	return ctx, func(err *errors.QueryError) {}
+}
+
+func (Tracer) TraceValidation(context.Context) func([]*errors.QueryError) {
+	return func(errs []*errors.QueryError) {}
+}

trace/noop/trace_test.go

@@ -0,0 +1,22 @@
+package noop_test
+
+import (
+	"testing"
+
+	"github.com/graph-gophers/graphql-go"
+	"github.com/graph-gophers/graphql-go/example/starwars"
+	"github.com/graph-gophers/graphql-go/trace/noop"
+	"github.com/graph-gophers/graphql-go/trace/tracer"
+)
+
+func TestInterfaceImplementation(t *testing.T) {
+	var _ tracer.ValidationTracer = &noop.Tracer{}
+	var _ tracer.Tracer = &noop.Tracer{}
+}
+
+func TestTracerOption(t *testing.T) {
+	_, err := graphql.ParseSchema(starwars.Schema, nil, graphql.Tracer(noop.Tracer{}))
+	if err != nil {
+		t.Fatal(err)
+	}
+}