forked from leanovate/gopter
/
forall.go
123 lines (110 loc) · 3.68 KB
/
forall.go
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
package prop
import (
"reflect"
"github.com/leanovate/gopter"
)
var typeOfError = reflect.TypeOf((*error)(nil)).Elem()
/*
ForAll creates a property that requires the check condition to be true for all values, if the
condition falsiies the generated values will be shrunk.
"condition" has to be a function with the same number of parameters as the provided
generators "gens". The function may return a simple bool (true means that the
condition has passed), a string (empty string means that condition has passed),
a *PropResult, or one of former combined with an error.
*/
func ForAll(condition interface{}, gens ...gopter.Gen) gopter.Prop {
callCheck, err := checkConditionFunc(condition, len(gens))
if err != nil {
return ErrorProp(err)
}
return gopter.SaveProp(func(genParams *gopter.GenParameters) *gopter.PropResult {
genResults := make([]*gopter.GenResult, len(gens))
values := make([]reflect.Value, len(gens))
var ok bool
for i, gen := range gens {
result := gen(genParams)
genResults[i] = result
values[i], ok = result.RetrieveAsValue()
if !ok {
return &gopter.PropResult{
Status: gopter.PropUndecided,
}
}
}
result := callCheck(values)
if result.Success() {
for i, genResult := range genResults {
result = result.AddArgs(gopter.NewPropArg(genResult, 0, values[i].Interface(), values[i].Interface()))
}
} else {
for i, genResult := range genResults {
nextResult, nextValue := shrinkValue(genParams.MaxShrinkCount, genResult, values[i].Interface(), result,
func(v interface{}) *gopter.PropResult {
shrunkOne := make([]reflect.Value, len(values))
copy(shrunkOne, values)
if v == nil {
shrunkOne[i] = reflect.Zero(values[i].Type())
} else {
shrunkOne[i] = reflect.ValueOf(v)
}
return callCheck(shrunkOne)
})
result = nextResult
if nextValue == nil {
values[i] = reflect.Zero(values[i].Type())
} else {
values[i] = reflect.ValueOf(nextValue)
}
}
}
return result
})
}
// ForAll1 legacy interface to be removed in the future
func ForAll1(gen gopter.Gen, check func(v interface{}) (interface{}, error)) gopter.Prop {
checkFunc := func(v interface{}) *gopter.PropResult {
return convertResult(check(v))
}
return gopter.SaveProp(func(genParams *gopter.GenParameters) *gopter.PropResult {
genResult := gen(genParams)
value, ok := genResult.Retrieve()
if !ok {
return &gopter.PropResult{
Status: gopter.PropUndecided,
}
}
result := checkFunc(value)
if result.Success() {
return result.AddArgs(gopter.NewPropArg(genResult, 0, value, value))
}
result, _ = shrinkValue(genParams.MaxShrinkCount, genResult, value, result, checkFunc)
return result
})
}
func shrinkValue(maxShrinkCount int, genResult *gopter.GenResult, origValue interface{},
firstFail *gopter.PropResult, check func(interface{}) *gopter.PropResult) (*gopter.PropResult, interface{}) {
lastFail := firstFail
lastValue := origValue
shrinks := 0
shrink := genResult.Shrinker(lastValue).Filter(genResult.Sieve)
nextResult, nextValue := firstFailure(shrink, check)
for nextResult != nil && shrinks < maxShrinkCount {
shrinks++
lastValue = nextValue
lastFail = nextResult
shrink = genResult.Shrinker(lastValue).Filter(genResult.Sieve)
nextResult, nextValue = firstFailure(shrink, check)
}
return lastFail.WithArgs(firstFail.Args).AddArgs(gopter.NewPropArg(genResult, shrinks, lastValue, origValue)), lastValue
}
func firstFailure(shrink gopter.Shrink, check func(interface{}) *gopter.PropResult) (*gopter.PropResult, interface{}) {
value, ok := shrink()
for ok {
result := check(value)
if !result.Success() {
return result, value
}
value, ok = shrink()
}
return nil, nil
}