Updated dependencies

vendor/github.com/99designs/gqlgen/handler/graphql.go

@@ -0,0 +1,467 @@
+package handler
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/99designs/gqlgen/complexity"
+	"github.com/99designs/gqlgen/graphql"
+	"github.com/gorilla/websocket"
+	"github.com/hashicorp/golang-lru"
+	"github.com/vektah/gqlparser/ast"
+	"github.com/vektah/gqlparser/gqlerror"
+	"github.com/vektah/gqlparser/parser"
+	"github.com/vektah/gqlparser/validator"
+)
+
+type params struct {
+	Query         string                 `json:"query"`
+	OperationName string                 `json:"operationName"`
+	Variables     map[string]interface{} `json:"variables"`
+}
+
+type Config struct {
+	cacheSize            int
+	upgrader             websocket.Upgrader
+	recover              graphql.RecoverFunc
+	errorPresenter       graphql.ErrorPresenterFunc
+	resolverHook         graphql.FieldMiddleware
+	requestHook          graphql.RequestMiddleware
+	tracer               graphql.Tracer
+	complexityLimit      int
+	disableIntrospection bool
+}
+
+func (c *Config) newRequestContext(es graphql.ExecutableSchema, doc *ast.QueryDocument, op *ast.OperationDefinition, query string, variables map[string]interface{}) *graphql.RequestContext {
+	reqCtx := graphql.NewRequestContext(doc, query, variables)
+	reqCtx.DisableIntrospection = c.disableIntrospection
+
+	if hook := c.recover; hook != nil {
+		reqCtx.Recover = hook
+	}
+
+	if hook := c.errorPresenter; hook != nil {
+		reqCtx.ErrorPresenter = hook
+	}
+
+	if hook := c.resolverHook; hook != nil {
+		reqCtx.ResolverMiddleware = hook
+	}
+
+	if hook := c.requestHook; hook != nil {
+		reqCtx.RequestMiddleware = hook
+	}
+
+	if hook := c.tracer; hook != nil {
+		reqCtx.Tracer = hook
+	}
+
+	if c.complexityLimit > 0 {
+		reqCtx.ComplexityLimit = c.complexityLimit
+		operationComplexity := complexity.Calculate(es, op, variables)
+		reqCtx.OperationComplexity = operationComplexity
+	}
+
+	return reqCtx
+}
+
+type Option func(cfg *Config)
+
+func WebsocketUpgrader(upgrader websocket.Upgrader) Option {
+	return func(cfg *Config) {
+		cfg.upgrader = upgrader
+	}
+}
+
+func RecoverFunc(recover graphql.RecoverFunc) Option {
+	return func(cfg *Config) {
+		cfg.recover = recover
+	}
+}
+
+// ErrorPresenter transforms errors found while resolving into errors that will be returned to the user. It provides
+// a good place to add any extra fields, like error.type, that might be desired by your frontend. Check the default
+// implementation in graphql.DefaultErrorPresenter for an example.
+func ErrorPresenter(f graphql.ErrorPresenterFunc) Option {
+	return func(cfg *Config) {
+		cfg.errorPresenter = f
+	}
+}
+
+// IntrospectionEnabled = false will forbid clients from calling introspection endpoints. Can be useful in prod when you dont
+// want clients introspecting the full schema.
+func IntrospectionEnabled(enabled bool) Option {
+	return func(cfg *Config) {
+		cfg.disableIntrospection = !enabled
+	}
+}
+
+// ComplexityLimit sets a maximum query complexity that is allowed to be executed.
+// If a query is submitted that exceeds the limit, a 422 status code will be returned.
+func ComplexityLimit(limit int) Option {
+	return func(cfg *Config) {
+		cfg.complexityLimit = limit
+	}
+}
+
+// ResolverMiddleware allows you to define a function that will be called around every resolver,
+// useful for logging.
+func ResolverMiddleware(middleware graphql.FieldMiddleware) Option {
+	return func(cfg *Config) {
+		if cfg.resolverHook == nil {
+			cfg.resolverHook = middleware
+			return
+		}
+
+		lastResolve := cfg.resolverHook
+		cfg.resolverHook = func(ctx context.Context, next graphql.Resolver) (res interface{}, err error) {
+			return lastResolve(ctx, func(ctx context.Context) (res interface{}, err error) {
+				return middleware(ctx, next)
+			})
+		}
+	}
+}
+
+// RequestMiddleware allows you to define a function that will be called around the root request,
+// after the query has been parsed. This is useful for logging
+func RequestMiddleware(middleware graphql.RequestMiddleware) Option {
+	return func(cfg *Config) {
+		if cfg.requestHook == nil {
+			cfg.requestHook = middleware
+			return
+		}
+
+		lastResolve := cfg.requestHook
+		cfg.requestHook = func(ctx context.Context, next func(ctx context.Context) []byte) []byte {
+			return lastResolve(ctx, func(ctx context.Context) []byte {
+				return middleware(ctx, next)
+			})
+		}
+	}
+}
+
+// Tracer allows you to add a request/resolver tracer that will be called around the root request,
+// calling resolver. This is useful for tracing
+func Tracer(tracer graphql.Tracer) Option {
+	return func(cfg *Config) {
+		if cfg.tracer == nil {
+			cfg.tracer = tracer
+
+		} else {
+			lastResolve := cfg.tracer
+			cfg.tracer = &tracerWrapper{
+				tracer1: lastResolve,
+				tracer2: tracer,
+			}
+		}
+
+		opt := RequestMiddleware(func(ctx context.Context, next func(ctx context.Context) []byte) []byte {
+			ctx = tracer.StartOperationExecution(ctx)
+			resp := next(ctx)
+			tracer.EndOperationExecution(ctx)
+
+			return resp
+		})
+		opt(cfg)
+	}
+}
+
+type tracerWrapper struct {
+	tracer1 graphql.Tracer
+	tracer2 graphql.Tracer
+}
+
+func (tw *tracerWrapper) StartOperationParsing(ctx context.Context) context.Context {
+	ctx = tw.tracer1.StartOperationParsing(ctx)
+	ctx = tw.tracer2.StartOperationParsing(ctx)
+	return ctx
+}
+
+func (tw *tracerWrapper) EndOperationParsing(ctx context.Context) {
+	tw.tracer2.EndOperationParsing(ctx)
+	tw.tracer1.EndOperationParsing(ctx)
+}
+
+func (tw *tracerWrapper) StartOperationValidation(ctx context.Context) context.Context {
+	ctx = tw.tracer1.StartOperationValidation(ctx)
+	ctx = tw.tracer2.StartOperationValidation(ctx)
+	return ctx
+}
+
+func (tw *tracerWrapper) EndOperationValidation(ctx context.Context) {
+	tw.tracer2.EndOperationValidation(ctx)
+	tw.tracer1.EndOperationValidation(ctx)
+}
+
+func (tw *tracerWrapper) StartOperationExecution(ctx context.Context) context.Context {
+	ctx = tw.tracer1.StartOperationExecution(ctx)
+	ctx = tw.tracer2.StartOperationExecution(ctx)
+	return ctx
+}
+
+func (tw *tracerWrapper) StartFieldExecution(ctx context.Context, field graphql.CollectedField) context.Context {
+	ctx = tw.tracer1.StartFieldExecution(ctx, field)
+	ctx = tw.tracer2.StartFieldExecution(ctx, field)
+	return ctx
+}
+
+func (tw *tracerWrapper) StartFieldResolverExecution(ctx context.Context, rc *graphql.ResolverContext) context.Context {
+	ctx = tw.tracer1.StartFieldResolverExecution(ctx, rc)
+	ctx = tw.tracer2.StartFieldResolverExecution(ctx, rc)
+	return ctx
+}
+
+func (tw *tracerWrapper) StartFieldChildExecution(ctx context.Context) context.Context {
+	ctx = tw.tracer1.StartFieldChildExecution(ctx)
+	ctx = tw.tracer2.StartFieldChildExecution(ctx)
+	return ctx
+}
+
+func (tw *tracerWrapper) EndFieldExecution(ctx context.Context) {
+	tw.tracer2.EndFieldExecution(ctx)
+	tw.tracer1.EndFieldExecution(ctx)
+}
+
+func (tw *tracerWrapper) EndOperationExecution(ctx context.Context) {
+	tw.tracer2.EndOperationExecution(ctx)
+	tw.tracer1.EndOperationExecution(ctx)
+}
+
+// CacheSize sets the maximum size of the query cache.
+// If size is less than or equal to 0, the cache is disabled.
+func CacheSize(size int) Option {
+	return func(cfg *Config) {
+		cfg.cacheSize = size
+	}
+}
+
+const DefaultCacheSize = 1000
+
+func GraphQL(exec graphql.ExecutableSchema, options ...Option) http.HandlerFunc {
+	cfg := &Config{
+		cacheSize: DefaultCacheSize,
+		upgrader: websocket.Upgrader{
+			ReadBufferSize:  1024,
+			WriteBufferSize: 1024,
+		},
+	}
+
+	for _, option := range options {
+		option(cfg)
+	}
+
+	var cache *lru.Cache
+	if cfg.cacheSize > 0 {
+		var err error
+		cache, err = lru.New(cfg.cacheSize)
+		if err != nil {
+			// An error is only returned for non-positive cache size
+			// and we already checked for that.
+			panic("unexpected error creating cache: " + err.Error())
+		}
+	}
+	if cfg.tracer == nil {
+		cfg.tracer = &graphql.NopTracer{}
+	}
+
+	handler := &graphqlHandler{
+		cfg:   cfg,
+		cache: cache,
+		exec:  exec,
+	}
+
+	return handler.ServeHTTP
+}
+
+var _ http.Handler = (*graphqlHandler)(nil)
+
+type graphqlHandler struct {
+	cfg   *Config
+	cache *lru.Cache
+	exec  graphql.ExecutableSchema
+}
+
+func (gh *graphqlHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method == http.MethodOptions {
+		w.Header().Set("Allow", "OPTIONS, GET, POST")
+		w.WriteHeader(http.StatusOK)
+		return
+	}
+
+	if strings.Contains(r.Header.Get("Upgrade"), "websocket") {
+		connectWs(gh.exec, w, r, gh.cfg, gh.cache)
+		return
+	}
+
+	var reqParams params
+	switch r.Method {
+	case http.MethodGet:
+		reqParams.Query = r.URL.Query().Get("query")
+		reqParams.OperationName = r.URL.Query().Get("operationName")
+
+		if variables := r.URL.Query().Get("variables"); variables != "" {
+			if err := jsonDecode(strings.NewReader(variables), &reqParams.Variables); err != nil {
+				sendErrorf(w, http.StatusBadRequest, "variables could not be decoded")
+				return
+			}
+		}
+	case http.MethodPost:
+		if err := jsonDecode(r.Body, &reqParams); err != nil {
+			sendErrorf(w, http.StatusBadRequest, "json body could not be decoded: "+err.Error())
+			return
+		}
+	default:
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+
+	ctx := r.Context()
+
+	var doc *ast.QueryDocument
+	var cacheHit bool
+	if gh.cache != nil {
+		val, ok := gh.cache.Get(reqParams.Query)
+		if ok {
+			doc = val.(*ast.QueryDocument)
+			cacheHit = true
+		}
+	}
+
+	ctx, doc, gqlErr := gh.parseOperation(ctx, &parseOperationArgs{
+		Query:     reqParams.Query,
+		CachedDoc: doc,
+	})
+	if gqlErr != nil {
+		sendError(w, http.StatusUnprocessableEntity, gqlErr)
+		return
+	}
+
+	ctx, op, vars, listErr := gh.validateOperation(ctx, &validateOperationArgs{
+		Doc:           doc,
+		OperationName: reqParams.OperationName,
+		CacheHit:      cacheHit,
+		R:             r,
+		Variables:     reqParams.Variables,
+	})
+	if len(listErr) != 0 {
+		sendError(w, http.StatusUnprocessableEntity, listErr...)
+		return
+	}
+
+	if gh.cache != nil && !cacheHit {
+		gh.cache.Add(reqParams.Query, doc)
+	}
+
+	reqCtx := gh.cfg.newRequestContext(gh.exec, doc, op, reqParams.Query, vars)
+	ctx = graphql.WithRequestContext(ctx, reqCtx)
+
+	defer func() {
+		if err := recover(); err != nil {
+			userErr := reqCtx.Recover(ctx, err)
+			sendErrorf(w, http.StatusUnprocessableEntity, userErr.Error())
+		}
+	}()
+
+	if reqCtx.ComplexityLimit > 0 && reqCtx.OperationComplexity > reqCtx.ComplexityLimit {
+		sendErrorf(w, http.StatusUnprocessableEntity, "operation has complexity %d, which exceeds the limit of %d", reqCtx.OperationComplexity, reqCtx.ComplexityLimit)
+		return
+	}
+
+	switch op.Operation {
+	case ast.Query:
+		b, err := json.Marshal(gh.exec.Query(ctx, op))
+		if err != nil {
+			panic(err)
+		}
+		w.Write(b)
+	case ast.Mutation:
+		b, err := json.Marshal(gh.exec.Mutation(ctx, op))
+		if err != nil {
+			panic(err)
+		}
+		w.Write(b)
+	default:
+		sendErrorf(w, http.StatusBadRequest, "unsupported operation type")
+	}
+}
+
+type parseOperationArgs struct {
+	Query     string
+	CachedDoc *ast.QueryDocument
+}
+
+func (gh *graphqlHandler) parseOperation(ctx context.Context, args *parseOperationArgs) (context.Context, *ast.QueryDocument, *gqlerror.Error) {
+	ctx = gh.cfg.tracer.StartOperationParsing(ctx)
+	defer func() { gh.cfg.tracer.EndOperationParsing(ctx) }()
+
+	if args.CachedDoc != nil {
+		return ctx, args.CachedDoc, nil
+	}
+
+	doc, gqlErr := parser.ParseQuery(&ast.Source{Input: args.Query})
+	if gqlErr != nil {
+		return ctx, nil, gqlErr
+	}
+
+	return ctx, doc, nil
+}
+
+type validateOperationArgs struct {
+	Doc           *ast.QueryDocument
+	OperationName string
+	CacheHit      bool
+	R             *http.Request
+	Variables     map[string]interface{}
+}
+
+func (gh *graphqlHandler) validateOperation(ctx context.Context, args *validateOperationArgs) (context.Context, *ast.OperationDefinition, map[string]interface{}, gqlerror.List) {
+	ctx = gh.cfg.tracer.StartOperationValidation(ctx)
+	defer func() { gh.cfg.tracer.EndOperationValidation(ctx) }()
+
+	if !args.CacheHit {
+		listErr := validator.Validate(gh.exec.Schema(), args.Doc)
+		if len(listErr) != 0 {
+			return ctx, nil, nil, listErr
+		}
+	}
+
+	op := args.Doc.Operations.ForName(args.OperationName)
+	if op == nil {
+		return ctx, nil, nil, gqlerror.List{gqlerror.Errorf("operation %s not found", args.OperationName)}
+	}
+
+	if op.Operation != ast.Query && args.R.Method == http.MethodGet {
+		return ctx, nil, nil, gqlerror.List{gqlerror.Errorf("GET requests only allow query operations")}
+	}
+
+	vars, err := validator.VariableValues(gh.exec.Schema(), op, args.Variables)
+	if err != nil {
+		return ctx, nil, nil, gqlerror.List{err}
+	}
+
+	return ctx, op, vars, nil
+}
+
+func jsonDecode(r io.Reader, val interface{}) error {
+	dec := json.NewDecoder(r)
+	dec.UseNumber()
+	return dec.Decode(val)
+}
+
+func sendError(w http.ResponseWriter, code int, errors ...*gqlerror.Error) {
+	w.WriteHeader(code)
+	b, err := json.Marshal(&graphql.Response{Errors: errors})
+	if err != nil {
+		panic(err)
+	}
+	w.Write(b)
+}
+
+func sendErrorf(w http.ResponseWriter, code int, format string, args ...interface{}) {
+	sendError(w, code, &gqlerror.Error{Message: fmt.Sprintf(format, args...)})
+}