82 lines
2.7 KiB
Go
82 lines
2.7 KiB
Go
package matchers
|
|
|
|
import (
|
|
"fmt"
|
|
"reflect"
|
|
|
|
"github.com/onsi/gomega/internal/oraclematcher"
|
|
"github.com/onsi/gomega/types"
|
|
)
|
|
|
|
type WithTransformMatcher struct {
|
|
// input
|
|
Transform interface{} // must be a function of one parameter that returns one value
|
|
Matcher types.GomegaMatcher
|
|
|
|
// cached value
|
|
transformArgType reflect.Type
|
|
|
|
// state
|
|
transformedValue interface{}
|
|
}
|
|
|
|
func NewWithTransformMatcher(transform interface{}, matcher types.GomegaMatcher) *WithTransformMatcher {
|
|
if transform == nil {
|
|
panic("transform function cannot be nil")
|
|
}
|
|
txType := reflect.TypeOf(transform)
|
|
if txType.NumIn() != 1 {
|
|
panic("transform function must have 1 argument")
|
|
}
|
|
if txType.NumOut() != 1 {
|
|
panic("transform function must have 1 return value")
|
|
}
|
|
|
|
return &WithTransformMatcher{
|
|
Transform: transform,
|
|
Matcher: matcher,
|
|
transformArgType: reflect.TypeOf(transform).In(0),
|
|
}
|
|
}
|
|
|
|
func (m *WithTransformMatcher) Match(actual interface{}) (bool, error) {
|
|
// prepare a parameter to pass to the Transform function
|
|
var param reflect.Value
|
|
if actual != nil && reflect.TypeOf(actual).AssignableTo(m.transformArgType) {
|
|
// The dynamic type of actual is compatible with the transform argument.
|
|
param = reflect.ValueOf(actual)
|
|
|
|
} else if actual == nil && m.transformArgType.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 transform argument, which is known.
|
|
param = reflect.Zero(m.transformArgType)
|
|
|
|
} else {
|
|
return false, fmt.Errorf("Transform function expects '%s' but we have '%T'", m.transformArgType, actual)
|
|
}
|
|
|
|
// call the Transform function with `actual`
|
|
fn := reflect.ValueOf(m.Transform)
|
|
result := fn.Call([]reflect.Value{param})
|
|
m.transformedValue = result[0].Interface() // expect exactly one value
|
|
|
|
return m.Matcher.Match(m.transformedValue)
|
|
}
|
|
|
|
func (m *WithTransformMatcher) FailureMessage(_ interface{}) (message string) {
|
|
return m.Matcher.FailureMessage(m.transformedValue)
|
|
}
|
|
|
|
func (m *WithTransformMatcher) NegatedFailureMessage(_ interface{}) (message string) {
|
|
return m.Matcher.NegatedFailureMessage(m.transformedValue)
|
|
}
|
|
|
|
func (m *WithTransformMatcher) MatchMayChangeInTheFuture(_ interface{}) bool {
|
|
// TODO: Maybe this should always just return true? (Only an issue for non-deterministic transformers.)
|
|
//
|
|
// Querying the next matcher is fine if the transformer always will return the same value.
|
|
// But if the transformer is non-deterministic and returns a different value each time, then there
|
|
// is no point in querying the next matcher, since it can only comment on the last transformed value.
|
|
return oraclematcher.MatchMayChangeInTheFuture(m.Matcher, m.transformedValue)
|
|
}
|