summaryrefslogtreecommitdiff
path: root/vendor/github.com/golang/mock/gomock/controller.go
blob: a7b79188bc8ceed45be0e492186e482769d820a4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
// Copyright 2010 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// GoMock - a mock framework for Go.
//
// Standard usage:
//   (1) Define an interface that you wish to mock.
//         type MyInterface interface {
//           SomeMethod(x int64, y string)
//         }
//   (2) Use mockgen to generate a mock from the interface.
//   (3) Use the mock in a test:
//         func TestMyThing(t *testing.T) {
//           mockCtrl := gomock.NewController(t)
//           defer mockCtrl.Finish()
//
//           mockObj := something.NewMockMyInterface(mockCtrl)
//           mockObj.EXPECT().SomeMethod(4, "blah")
//           // pass mockObj to a real object and play with it.
//         }
//
// By default, expected calls are not enforced to run in any particular order.
// Call order dependency can be enforced by use of InOrder and/or Call.After.
// Call.After can create more varied call order dependencies, but InOrder is
// often more convenient.
//
// The following examples create equivalent call order dependencies.
//
// Example of using Call.After to chain expected call order:
//
//     firstCall := mockObj.EXPECT().SomeMethod(1, "first")
//     secondCall := mockObj.EXPECT().SomeMethod(2, "second").After(firstCall)
//     mockObj.EXPECT().SomeMethod(3, "third").After(secondCall)
//
// Example of using InOrder to declare expected call order:
//
//     gomock.InOrder(
//         mockObj.EXPECT().SomeMethod(1, "first"),
//         mockObj.EXPECT().SomeMethod(2, "second"),
//         mockObj.EXPECT().SomeMethod(3, "third"),
//     )
//
// TODO:
//	- Handle different argument/return types (e.g. ..., chan, map, interface).
package gomock

import (
	"fmt"
	"golang.org/x/net/context"
	"reflect"
	"runtime"
	"sync"
)

// A TestReporter is something that can be used to report test failures.
// It is satisfied by the standard library's *testing.T.
type TestReporter interface {
	Errorf(format string, args ...interface{})
	Fatalf(format string, args ...interface{})
}

// A Controller represents the top-level control of a mock ecosystem.
// It defines the scope and lifetime of mock objects, as well as their expectations.
// It is safe to call Controller's methods from multiple goroutines.
type Controller struct {
	mu            sync.Mutex
	t             TestReporter
	expectedCalls *callSet
	finished      bool
}

func NewController(t TestReporter) *Controller {
	return &Controller{
		t:             t,
		expectedCalls: newCallSet(),
	}
}

type cancelReporter struct {
	t      TestReporter
	cancel func()
}

func (r *cancelReporter) Errorf(format string, args ...interface{}) { r.t.Errorf(format, args...) }
func (r *cancelReporter) Fatalf(format string, args ...interface{}) {
	defer r.cancel()
	r.t.Fatalf(format, args...)
}

// WithContext returns a new Controller and a Context, which is cancelled on any
// fatal failure.
func WithContext(ctx context.Context, t TestReporter) (*Controller, context.Context) {
	ctx, cancel := context.WithCancel(ctx)
	return NewController(&cancelReporter{t, cancel}), ctx
}

func (ctrl *Controller) RecordCall(receiver interface{}, method string, args ...interface{}) *Call {
	if h, ok := ctrl.t.(testHelper); ok {
		h.Helper()
	}

	recv := reflect.ValueOf(receiver)
	for i := 0; i < recv.Type().NumMethod(); i++ {
		if recv.Type().Method(i).Name == method {
			return ctrl.RecordCallWithMethodType(receiver, method, recv.Method(i).Type(), args...)
		}
	}
	ctrl.t.Fatalf("gomock: failed finding method %s on %T", method, receiver)
	panic("unreachable")
}

func (ctrl *Controller) RecordCallWithMethodType(receiver interface{}, method string, methodType reflect.Type, args ...interface{}) *Call {
	if h, ok := ctrl.t.(testHelper); ok {
		h.Helper()
	}

	call := newCall(ctrl.t, receiver, method, methodType, args...)

	ctrl.mu.Lock()
	defer ctrl.mu.Unlock()
	ctrl.expectedCalls.Add(call)

	return call
}

func (ctrl *Controller) Call(receiver interface{}, method string, args ...interface{}) []interface{} {
	if h, ok := ctrl.t.(testHelper); ok {
		h.Helper()
	}

	// Nest this code so we can use defer to make sure the lock is released.
	actions := func() []func([]interface{}) []interface{} {
		ctrl.mu.Lock()
		defer ctrl.mu.Unlock()

		expected, err := ctrl.expectedCalls.FindMatch(receiver, method, args)
		if err != nil {
			origin := callerInfo(2)
			ctrl.t.Fatalf("Unexpected call to %T.%v(%v) at %s because: %s", receiver, method, args, origin, err)
		}

		// Two things happen here:
		// * the matching call no longer needs to check prerequite calls,
		// * and the prerequite calls are no longer expected, so remove them.
		preReqCalls := expected.dropPrereqs()
		for _, preReqCall := range preReqCalls {
			ctrl.expectedCalls.Remove(preReqCall)
		}

		actions := expected.call(args)
		if expected.exhausted() {
			ctrl.expectedCalls.Remove(expected)
		}
		return actions
	}()

	var rets []interface{}
	for _, action := range actions {
		if r := action(args); r != nil {
			rets = r
		}
	}

	return rets
}

func (ctrl *Controller) Finish() {
	if h, ok := ctrl.t.(testHelper); ok {
		h.Helper()
	}

	ctrl.mu.Lock()
	defer ctrl.mu.Unlock()

	if ctrl.finished {
		ctrl.t.Fatalf("Controller.Finish was called more than once. It has to be called exactly once.")
	}
	ctrl.finished = true

	// If we're currently panicking, probably because this is a deferred call,
	// pass through the panic.
	if err := recover(); err != nil {
		panic(err)
	}

	// Check that all remaining expected calls are satisfied.
	failures := ctrl.expectedCalls.Failures()
	for _, call := range failures {
		ctrl.t.Errorf("missing call(s) to %v", call)
	}
	if len(failures) != 0 {
		ctrl.t.Fatalf("aborting test due to missing call(s)")
	}
}

func callerInfo(skip int) string {
	if _, file, line, ok := runtime.Caller(skip + 1); ok {
		return fmt.Sprintf("%s:%d", file, line)
	}
	return "unknown file"
}

type testHelper interface {
	TestReporter
	Helper()
}