panic_matcher.go

Documentation: github.com/onsi/gomega/matchers

     1  package matchers
     2  
     3  import (
     4  	"fmt"
     5  	"reflect"
     6  
     7  	"github.com/onsi/gomega/format"
     8  )
     9  
    10  type PanicMatcher struct {
    11  	Expected interface{}
    12  	object   interface{}
    13  }
    14  
    15  func (matcher *PanicMatcher) Match(actual interface{}) (success bool, err error) {
    16  	if actual == nil {
    17  		return false, fmt.Errorf("PanicMatcher expects a non-nil actual.")
    18  	}
    19  
    20  	actualType := reflect.TypeOf(actual)
    21  	if actualType.Kind() != reflect.Func {
    22  		return false, fmt.Errorf("PanicMatcher expects a function.  Got:\n%s", format.Object(actual, 1))
    23  	}
    24  	if !(actualType.NumIn() == 0 && actualType.NumOut() == 0) {
    25  		return false, fmt.Errorf("PanicMatcher expects a function with no arguments and no return value.  Got:\n%s", format.Object(actual, 1))
    26  	}
    27  
    28  	success = false
    29  	defer func() {
    30  		if e := recover(); e != nil {
    31  			matcher.object = e
    32  
    33  			if matcher.Expected == nil {
    34  				success = true
    35  				return
    36  			}
    37  
    38  			valueMatcher, valueIsMatcher := matcher.Expected.(omegaMatcher)
    39  			if !valueIsMatcher {
    40  				valueMatcher = &EqualMatcher{Expected: matcher.Expected}
    41  			}
    42  
    43  			success, err = valueMatcher.Match(e)
    44  			if err != nil {
    45  				err = fmt.Errorf("PanicMatcher's value matcher failed with:\n%s%s", format.Indent, err.Error())
    46  			}
    47  		}
    48  	}()
    49  
    50  	reflect.ValueOf(actual).Call([]reflect.Value{})
    51  
    52  	return
    53  }
    54  
    55  func (matcher *PanicMatcher) FailureMessage(actual interface{}) (message string) {
    56  	if matcher.Expected == nil {
    57  		// We wanted any panic to occur, but none did.
    58  		return format.Message(actual, "to panic")
    59  	}
    60  
    61  	if matcher.object == nil {
    62  		// We wanted a panic with a specific value to occur, but none did.
    63  		switch matcher.Expected.(type) {
    64  		case omegaMatcher:
    65  			return format.Message(actual, "to panic with a value matching", matcher.Expected)
    66  		default:
    67  			return format.Message(actual, "to panic with", matcher.Expected)
    68  		}
    69  	}
    70  
    71  	// We got a panic, but the value isn't what we expected.
    72  	switch matcher.Expected.(type) {
    73  	case omegaMatcher:
    74  		return format.Message(
    75  			actual,
    76  			fmt.Sprintf(
    77  				"to panic with a value matching\n%s\nbut panicked with\n%s",
    78  				format.Object(matcher.Expected, 1),
    79  				format.Object(matcher.object, 1),
    80  			),
    81  		)
    82  	default:
    83  		return format.Message(
    84  			actual,
    85  			fmt.Sprintf(
    86  				"to panic with\n%s\nbut panicked with\n%s",
    87  				format.Object(matcher.Expected, 1),
    88  				format.Object(matcher.object, 1),
    89  			),
    90  		)
    91  	}
    92  }
    93  
    94  func (matcher *PanicMatcher) NegatedFailureMessage(actual interface{}) (message string) {
    95  	if matcher.Expected == nil {
    96  		// We didn't want any panic to occur, but one did.
    97  		return format.Message(actual, fmt.Sprintf("not to panic, but panicked with\n%s", format.Object(matcher.object, 1)))
    98  	}
    99  
   100  	// We wanted a to ensure a panic with a specific value did not occur, but it did.
   101  	switch matcher.Expected.(type) {
   102  	case omegaMatcher:
   103  		return format.Message(
   104  			actual,
   105  			fmt.Sprintf(
   106  				"not to panic with a value matching\n%s\nbut panicked with\n%s",
   107  				format.Object(matcher.Expected, 1),
   108  				format.Object(matcher.object, 1),
   109  			),
   110  		)
   111  	default:
   112  		return format.Message(actual, "not to panic with", matcher.Expected)
   113  	}
   114  }
   115
View as plain text