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
|
// run
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// short-circuiting interface-to-concrete comparisons
// will not miss panics
package main
import (
"log"
"strings"
)
func main() {
var (
x interface{}
p *int
s []int
l *interface{}
r []*int
)
tests := []struct {
name string
errStr string
f func()
}{
{"switch case", "", func() {
switch x {
case x.(*int):
}
}},
{"interface conversion", "", func() { _ = x == x.(error) }},
{"type assertion", "", func() { _ = x == x.(*int) }},
{"out of bounds", "", func() { _ = x == s[1] }},
{"nil pointer dereference #1", "", func() { _ = x == *p }},
{"nil pointer dereference #2", "nil pointer dereference", func() { _ = *l == r[0] }},
}
for _, tc := range tests {
testFuncShouldPanic(tc.name, tc.errStr, tc.f)
}
}
func testFuncShouldPanic(name, errStr string, f func()) {
defer func() {
e := recover()
if e == nil {
log.Fatalf("%s: comparison did not panic\n", name)
}
if errStr != "" {
if !strings.Contains(e.(error).Error(), errStr) {
log.Fatalf("%s: wrong panic message\n", name)
}
}
}()
f()
}
|
