1 // Copyright (c) 2016 Uber Technologies, Inc.
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining a copy
4 // of this software and associated documentation files (the "Software"), to deal
5 // in the Software without restriction, including without limitation the rights
6 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7 // copies of the Software, and to permit persons to whom the Software is
8 // furnished to do so, subject to the following conditions:
9 //
10 // The above copyright notice and this permission notice shall be included in
11 // all copies or substantial portions of the Software.
12 //
13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19 // THE SOFTWARE.
20 21 // Package exit provides stubs so that unit tests can exercise code that calls
22 // os.Exit(1).
23 package exit
24 25 import "os"
26 27 var _exit = os.Exit
28 29 // With terminates the process by calling os.Exit(code). If the package is
30 // stubbed, it instead records a call in the testing spy.
31 func With(code int) {
32 _exit(code)
33 }
34 35 // A StubbedExit is a testing fake for os.Exit.
36 type StubbedExit struct {
37 Exited bool
38 Code int
39 prev func(code int)
40 }
41 42 // Stub substitutes a fake for the call to os.Exit(1).
43 func Stub() *StubbedExit {
44 s := &StubbedExit{prev: _exit}
45 _exit = s.exit
46 return s
47 }
48 49 // WithStub runs the supplied function with Exit stubbed. It returns the stub
50 // used, so that users can test whether the process would have crashed.
51 func WithStub(f func()) *StubbedExit {
52 s := Stub()
53 defer s.Unstub()
54 f()
55 return s
56 }
57 58 // Unstub restores the previous exit function.
59 func (se *StubbedExit) Unstub() {
60 _exit = se.prev
61 }
62 63 func (se *StubbedExit) exit(code int) {
64 se.Exited = true
65 se.Code = code
66 }
67