1// untested sections: 4
  2
  3package matchers
  4
  5import (
  6	"fmt"
  7	"math"
  8
  9	"github.com/onsi/gomega/format"
 10)
 11
 12type BeNumericallyMatcher struct {
 13	Comparator string
 14	CompareTo  []interface{}
 15}
 16
 17func (matcher *BeNumericallyMatcher) FailureMessage(actual interface{}) (message string) {
 18	return matcher.FormatFailureMessage(actual, false)
 19}
 20
 21func (matcher *BeNumericallyMatcher) NegatedFailureMessage(actual interface{}) (message string) {
 22	return matcher.FormatFailureMessage(actual, true)
 23}
 24
 25func (matcher *BeNumericallyMatcher) FormatFailureMessage(actual interface{}, negated bool) (message string) {
 26	if len(matcher.CompareTo) == 1 {
 27		message = fmt.Sprintf("to be %s", matcher.Comparator)
 28	} else {
 29		message = fmt.Sprintf("to be within %v of %s", matcher.CompareTo[1], matcher.Comparator)
 30	}
 31	if negated {
 32		message = "not " + message
 33	}
 34	return format.Message(actual, message, matcher.CompareTo[0])
 35}
 36
 37func (matcher *BeNumericallyMatcher) Match(actual interface{}) (success bool, err error) {
 38	if len(matcher.CompareTo) == 0 || len(matcher.CompareTo) > 2 {
 39		return false, fmt.Errorf("BeNumerically requires 1 or 2 CompareTo arguments.  Got:\n%s", format.Object(matcher.CompareTo, 1))
 40	}
 41	if !isNumber(actual) {
 42		return false, fmt.Errorf("Expected a number.  Got:\n%s", format.Object(actual, 1))
 43	}
 44	if !isNumber(matcher.CompareTo[0]) {
 45		return false, fmt.Errorf("Expected a number.  Got:\n%s", format.Object(matcher.CompareTo[0], 1))
 46	}
 47	if len(matcher.CompareTo) == 2 && !isNumber(matcher.CompareTo[1]) {
 48		return false, fmt.Errorf("Expected a number.  Got:\n%s", format.Object(matcher.CompareTo[1], 1))
 49	}
 50
 51	switch matcher.Comparator {
 52	case "==", "~", ">", ">=", "<", "<=":
 53	default:
 54		return false, fmt.Errorf("Unknown comparator: %s", matcher.Comparator)
 55	}
 56
 57	if isFloat(actual) || isFloat(matcher.CompareTo[0]) {
 58		var secondOperand float64 = 1e-8
 59		if len(matcher.CompareTo) == 2 {
 60			secondOperand = toFloat(matcher.CompareTo[1])
 61		}
 62		success = matcher.matchFloats(toFloat(actual), toFloat(matcher.CompareTo[0]), secondOperand)
 63	} else if isInteger(actual) {
 64		var secondOperand int64 = 0
 65		if len(matcher.CompareTo) == 2 {
 66			secondOperand = toInteger(matcher.CompareTo[1])
 67		}
 68		success = matcher.matchIntegers(toInteger(actual), toInteger(matcher.CompareTo[0]), secondOperand)
 69	} else if isUnsignedInteger(actual) {
 70		var secondOperand uint64 = 0
 71		if len(matcher.CompareTo) == 2 {
 72			secondOperand = toUnsignedInteger(matcher.CompareTo[1])
 73		}
 74		success = matcher.matchUnsignedIntegers(toUnsignedInteger(actual), toUnsignedInteger(matcher.CompareTo[0]), secondOperand)
 75	} else {
 76		return false, fmt.Errorf("Failed to compare:\n%s\n%s:\n%s", format.Object(actual, 1), matcher.Comparator, format.Object(matcher.CompareTo[0], 1))
 77	}
 78
 79	return success, nil
 80}
 81
 82func (matcher *BeNumericallyMatcher) matchIntegers(actual, compareTo, threshold int64) (success bool) {
 83	switch matcher.Comparator {
 84	case "==", "~":
 85		diff := actual - compareTo
 86		return -threshold <= diff && diff <= threshold
 87	case ">":
 88		return (actual > compareTo)
 89	case ">=":
 90		return (actual >= compareTo)
 91	case "<":
 92		return (actual < compareTo)
 93	case "<=":
 94		return (actual <= compareTo)
 95	}
 96	return false
 97}
 98
 99func (matcher *BeNumericallyMatcher) matchUnsignedIntegers(actual, compareTo, threshold uint64) (success bool) {
100	switch matcher.Comparator {
101	case "==", "~":
102		if actual < compareTo {
103			actual, compareTo = compareTo, actual
104		}
105		return actual-compareTo <= threshold
106	case ">":
107		return (actual > compareTo)
108	case ">=":
109		return (actual >= compareTo)
110	case "<":
111		return (actual < compareTo)
112	case "<=":
113		return (actual <= compareTo)
114	}
115	return false
116}
117
118func (matcher *BeNumericallyMatcher) matchFloats(actual, compareTo, threshold float64) (success bool) {
119	switch matcher.Comparator {
120	case "~":
121		return math.Abs(actual-compareTo) <= threshold
122	case "==":
123		return (actual == compareTo)
124	case ">":
125		return (actual > compareTo)
126	case ">=":
127		return (actual >= compareTo)
128	case "<":
129		return (actual < compareTo)
130	case "<=":
131		return (actual <= compareTo)
132	}
133	return false
134}