private/apigen: Don't allow certain types for Request/Response

We cannot map certain types to TypeScript, hence we verify them in the
Endpoint.Validate method.

Even some types could be somehow mapped, we don't want to add more
complexity or allow types that don't make sense to be for a request or
response.

Change-Id: I51ecee286e637b1160e967d77f9ce6c7403ddfdc

private/apigen/endpoint.go

@@ -81,6 +81,36 @@ func (e *Endpoint) Validate() error {
 		return errsEndpoint.New("TypeScriptName doesn't match the regular expression %q", typeScriptNameRegExp)
 	}
 
+	if e.Request != nil {
+		switch k := reflect.TypeOf(e.Request).Kind(); k {
+		case reflect.Invalid,
+			reflect.Complex64,
+			reflect.Complex128,
+			reflect.Chan,
+			reflect.Func,
+			reflect.Interface,
+			reflect.Map,
+			reflect.Pointer,
+			reflect.UnsafePointer:
+			return errsEndpoint.New("Request cannot be of a type %q", k)
+		}
+	}
+
+	if e.Response != nil {
+		switch k := reflect.TypeOf(e.Response).Kind(); k {
+		case reflect.Invalid,
+			reflect.Complex64,
+			reflect.Complex128,
+			reflect.Chan,
+			reflect.Func,
+			reflect.Interface,
+			reflect.Map,
+			reflect.Pointer,
+			reflect.UnsafePointer:
+			return errsEndpoint.New("Response cannot be of a type %q", k)
+		}
+	}
+
 	return nil
 }
 

private/apigen/endpoint_test.go

@@ -4,8 +4,10 @@
 package apigen
 
 import (
+	"fmt"
 	"math/rand"
 	"net/http"
+	"reflect"
 	"strconv"
 	"testing"
 
@@ -104,6 +106,27 @@ func TestEndpoint_Validate(t *testing.T) {
 			},
 			errMsg: "TypeScriptName doesn't match the regular expression",
 		},
+		{
+			testName: "invalid Request type",
+			endpointFn: func() *Endpoint {
+				request := &struct {
+					Name string `json:"name"`
+				}{}
+				e := validEndpoint
+				e.Request = request
+				return &e
+			},
+			errMsg: fmt.Sprintf("Request cannot be of a type %q", reflect.Pointer),
+		},
+		{
+			testName: "invalid Response type",
+			endpointFn: func() *Endpoint {
+				e := validEndpoint
+				e.Response = map[string]string{}
+				return &e
+			},
+			errMsg: fmt.Sprintf("Response cannot be of a type %q", reflect.Map),
+		},
 	}
 
 	for _, tc := range tcases {