add support for validator

internal/plugin/router.go

@@ -7,12 +7,15 @@ import (
 	"github.com/drone/drone-go/drone"
 	"github.com/drone/drone-go/plugin/converter"
 	"github.com/drone/drone-go/plugin/logger"
+	"github.com/drone/drone-go/plugin/validator"
 )
 
 type Router struct {
-	logger         logger.Logger
-	convertPlugins []converter.Plugin
-	convertHandler http.Handler
+	logger          logger.Logger
+	convertPlugins  []converter.Plugin
+	convertHandler  http.Handler
+	validatePlugins []validator.Plugin
+	validateHandler http.Handler
 }
 
 type RouterOption func(*Router)
@@ -23,6 +26,12 @@ func WithConvertPlugins(plugins ...converter.Plugin) RouterOption {
 	}
 }
 
+func WithValidatePlugins(plugins ...validator.Plugin) RouterOption {
+	return func(r *Router) {
+		r.validatePlugins = append(r.validatePlugins, plugins...)
+	}
+}
+
 func WithLogger(l logger.Logger) RouterOption {
 	return func(r *Router) {
 		r.logger = l
@@ -39,6 +48,7 @@ func NewRouter(secret string, opts ...RouterOption) *Router {
 	}
 
 	router.convertHandler = converter.Handler(router, secret, router.logger)
+	router.validateHandler = validator.Handler(secret, router, router.logger)
 
 	return router
 }
@@ -57,10 +67,22 @@ func (r *Router) Convert(ctx context.Context, req *converter.Request) (*drone.Co
 	return &req.Config, nil
 }
 
+func (r *Router) Validate(ctx context.Context, req *validator.Request) error {
+	for _, plugin := range r.validatePlugins {
+		if err := plugin.Validate(ctx, req); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (r *Router) ServeHTTP(res http.ResponseWriter, req *http.Request) {
 	switch req.Header.Get("Accept") {
 	case converter.V1:
 		r.convertHandler.ServeHTTP(res, req)
+	case validator.V1:
+		r.validateHandler.ServeHTTP(res, req)
 	default:
 		http.Error(res, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
 	}

internal/plugin/router_test.go

@@ -2,10 +2,13 @@ package plugin
 
 import (
 	"context"
+	"errors"
+	"strings"
 	"testing"
 
 	"github.com/drone/drone-go/drone"
 	"github.com/drone/drone-go/plugin/converter"
+	"github.com/drone/drone-go/plugin/validator"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -49,3 +52,52 @@ func TestConvertRouter(t *testing.T) {
 		assert.Equal(t, test.want, conf.Data, test.description)
 	}
 }
+
+// stringValidate returns an error if the passed in string is not in the validator requests Config.Data
+type stringValidate struct {
+	s string
+}
+
+func newStringValidate(s string) *stringValidate {
+	return &stringValidate{s: s}
+}
+
+func (p *stringValidate) Validate(ctx context.Context, req *validator.Request) error {
+	if !strings.Contains(req.Config.Data, p.s) {
+		return errors.New(p.s)
+	}
+
+	return nil
+}
+
+func TestValidateRouter(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		description string
+		router      *Router
+		input       string
+		err         error
+	}{
+		{
+			description: "test without validate plugins",
+			router:      NewRouter(""),
+		},
+		{
+			description: "test passing validate plugin",
+			router:      NewRouter("", WithValidatePlugins(newStringValidate("one"))),
+			input:       "one",
+		},
+		{
+			description: "test with multiple validate plugins and an error",
+			router:      NewRouter("", WithValidatePlugins(newStringValidate("one"), newStringValidate("two"))),
+			input:       "one",
+			err:         errors.New("two"),
+		},
+	}
+
+	for _, test := range tests {
+		req := &validator.Request{Config: drone.Config{Data: test.input}}
+		assert.Equal(t, test.err, test.router.Validate(context.TODO(), req))
+	}
+}