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
|
package matchers
import (
"fmt"
"reflect"
"github.com/onsi/gomega/format"
)
type SatisfyMatcher struct {
Predicate interface{}
// cached type
predicateArgType reflect.Type
}
func NewSatisfyMatcher(predicate interface{}) *SatisfyMatcher {
if predicate == nil {
panic("predicate cannot be nil")
}
predicateType := reflect.TypeOf(predicate)
if predicateType.Kind() != reflect.Func {
panic("predicate must be a function")
}
if predicateType.NumIn() != 1 {
panic("predicate must have 1 argument")
}
if predicateType.NumOut() != 1 || predicateType.Out(0).Kind() != reflect.Bool {
panic("predicate must return bool")
}
return &SatisfyMatcher{
Predicate: predicate,
predicateArgType: predicateType.In(0),
}
}
func (m *SatisfyMatcher) Match(actual interface{}) (success bool, err error) {
// prepare a parameter to pass to the predicate
var param reflect.Value
if actual != nil && reflect.TypeOf(actual).AssignableTo(m.predicateArgType) {
// The dynamic type of actual is compatible with the predicate argument.
param = reflect.ValueOf(actual)
} else if actual == nil && m.predicateArgType.Kind() == reflect.Interface {
// The dynamic type of actual is unknown, so there's no way to make its
// reflect.Value. Create a nil of the predicate argument, which is known.
param = reflect.Zero(m.predicateArgType)
} else {
return false, fmt.Errorf("predicate expects '%s' but we have '%T'", m.predicateArgType, actual)
}
// call the predicate with `actual`
fn := reflect.ValueOf(m.Predicate)
result := fn.Call([]reflect.Value{param})
return result[0].Bool(), nil
}
func (m *SatisfyMatcher) FailureMessage(actual interface{}) (message string) {
return format.Message(actual, "to satisfy predicate", m.Predicate)
}
func (m *SatisfyMatcher) NegatedFailureMessage(actual interface{}) (message string) {
return format.Message(actual, "to not satisfy predicate", m.Predicate)
}
|
