Test method validation and api setup function

proxy/methods.go

@@ -21,7 +21,7 @@ func validateMethod(apiMethod reflect.Method, serverType reflect.Type) error {
 	foundType := serverMethod.Type
 	err := validateArgs(expectedType, foundType)
 	if err != nil {
-		return fmt.Errorf("api/server arguments do not match for method (%s/%s): %v", name, trueName, err)
+		return fmt.Errorf("validation of %s to %s mapping: %v", name, trueName, err)
 	}
 	return nil
 }

proxy/methods_test.go

@@ -47,7 +47,7 @@ func Test_validateMethod(t *testing.T) {
 			name:        "invalid matching server method",
 			apiMethod:   reflect.TypeOf(&exposedThingA{}).Method(0),
 			serverType:  reflect.TypeOf(&thingB{}),
-			expectedErr: "api/server arguments do not match for method (PostDoThing/DoThing): api and server arguments mismatch: int vs string",
+			expectedErr: "validation of PostDoThing to DoThing mapping: api and server arguments mismatch: int vs string",
 		},
 	}
 	for _, tt := range tests {

proxy/server_test.go

@@ -0,0 +1 @@
+package proxy

proxy/setup_test.go

@@ -0,0 +1,76 @@
+package proxy
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type emptyThing struct{}
+
+func TestServer_setAPIConfig(t *testing.T) {
+	specificExposedThing := &exposedThingA{}
+	tests := []struct {
+		name        string
+		s           *Server
+		api         interface{}
+		server      interface{}
+		result      *Server
+		expectedErr string
+	}{
+		{
+			name:   "no functions",
+			s:      &Server{},
+			api:    &emptyThing{},
+			server: &emptyThing{},
+			result: &Server{
+				api:         []reflect.Method{},
+				innerServer: &emptyThing{},
+			},
+			expectedErr: "",
+		},
+		{
+			name:   "matching",
+			s:      &Server{},
+			api:    specificExposedThing,
+			server: &thingA{},
+			result: &Server{
+				api: []reflect.Method{
+					reflect.TypeOf(specificExposedThing).Method(0),
+				},
+				innerServer: &thingA{},
+			},
+			expectedErr: "",
+		},
+		{
+			name:        "mismatch",
+			s:           &Server{},
+			api:         specificExposedThing,
+			server:      &thingB{},
+			result:      &Server{},
+			expectedErr: "httpgrpc: validation of PostDoThing to DoThing mapping: api and server arguments mismatch: int vs string",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.s.setAPIConfig(tt.api, tt.server)
+			if tt.expectedErr == "" {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.result.grpcServer, tt.s.grpcServer)
+				assert.Equal(t, tt.result.innerServer, tt.s.innerServer)
+				if assert.Len(t, tt.s.api, len(tt.result.api)) {
+					for i, method := range tt.s.api {
+						expectedMethod := tt.result.api[i]
+						assert.Equal(t, method.Name, expectedMethod.Name)
+						assert.Equal(t, method.PkgPath, expectedMethod.PkgPath)
+						assert.Equal(t, method.Type, expectedMethod.Type)
+						assert.Equal(t, method.Index, expectedMethod.Index)
+					}
+				}
+			} else {
+				assert.EqualError(t, err, tt.expectedErr)
+			}
+		})
+	}
+}