githaven/vendor/github.com/smartystreets/assertions/internal/oglematchers/equals.go

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2016-11-03 22:16:01 +00:00
// Copyright 2011 Aaron Jacobs. All Rights Reserved.
// Author: aaronjjacobs@gmail.com (Aaron Jacobs)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package oglematchers
import (
"errors"
"fmt"
"math"
"reflect"
)
// Equals(x) returns a matcher that matches values v such that v and x are
// equivalent. This includes the case when the comparison v == x using Go's
// built-in comparison operator is legal (except for structs, which this
// matcher does not support), but for convenience the following rules also
// apply:
//
// * Type checking is done based on underlying types rather than actual
// types, so that e.g. two aliases for string can be compared:
//
// type stringAlias1 string
// type stringAlias2 string
//
// a := "taco"
// b := stringAlias1("taco")
// c := stringAlias2("taco")
//
// ExpectTrue(a == b) // Legal, passes
// ExpectTrue(b == c) // Illegal, doesn't compile
//
// ExpectThat(a, Equals(b)) // Passes
// ExpectThat(b, Equals(c)) // Passes
//
// * Values of numeric type are treated as if they were abstract numbers, and
// compared accordingly. Therefore Equals(17) will match int(17),
// int16(17), uint(17), float32(17), complex64(17), and so on.
//
// If you want a stricter matcher that contains no such cleverness, see
// IdenticalTo instead.
//
// Arrays are supported by this matcher, but do not participate in the
// exceptions above. Two arrays compared with this matcher must have identical
// types, and their element type must itself be comparable according to Go's ==
// operator.
func Equals(x interface{}) Matcher {
v := reflect.ValueOf(x)
// This matcher doesn't support structs.
if v.Kind() == reflect.Struct {
panic(fmt.Sprintf("oglematchers.Equals: unsupported kind %v", v.Kind()))
}
// The == operator is not defined for non-nil slices.
if v.Kind() == reflect.Slice && v.Pointer() != uintptr(0) {
panic(fmt.Sprintf("oglematchers.Equals: non-nil slice"))
}
return &equalsMatcher{v}
}
type equalsMatcher struct {
expectedValue reflect.Value
}
////////////////////////////////////////////////////////////////////////
// Numeric types
////////////////////////////////////////////////////////////////////////
func isSignedInteger(v reflect.Value) bool {
k := v.Kind()
return k >= reflect.Int && k <= reflect.Int64
}
func isUnsignedInteger(v reflect.Value) bool {
k := v.Kind()
return k >= reflect.Uint && k <= reflect.Uintptr
}
func isInteger(v reflect.Value) bool {
return isSignedInteger(v) || isUnsignedInteger(v)
}
func isFloat(v reflect.Value) bool {
k := v.Kind()
return k == reflect.Float32 || k == reflect.Float64
}
func isComplex(v reflect.Value) bool {
k := v.Kind()
return k == reflect.Complex64 || k == reflect.Complex128
}
func checkAgainstInt64(e int64, c reflect.Value) (err error) {
err = errors.New("")
switch {
case isSignedInteger(c):
if c.Int() == e {
err = nil
}
case isUnsignedInteger(c):
u := c.Uint()
if u <= math.MaxInt64 && int64(u) == e {
err = nil
}
// Turn around the various floating point types so that the checkAgainst*
// functions for them can deal with precision issues.
case isFloat(c), isComplex(c):
return Equals(c.Interface()).Matches(e)
default:
err = NewFatalError("which is not numeric")
}
return
}
func checkAgainstUint64(e uint64, c reflect.Value) (err error) {
err = errors.New("")
switch {
case isSignedInteger(c):
i := c.Int()
if i >= 0 && uint64(i) == e {
err = nil
}
case isUnsignedInteger(c):
if c.Uint() == e {
err = nil
}
// Turn around the various floating point types so that the checkAgainst*
// functions for them can deal with precision issues.
case isFloat(c), isComplex(c):
return Equals(c.Interface()).Matches(e)
default:
err = NewFatalError("which is not numeric")
}
return
}
func checkAgainstFloat32(e float32, c reflect.Value) (err error) {
err = errors.New("")
switch {
case isSignedInteger(c):
if float32(c.Int()) == e {
err = nil
}
case isUnsignedInteger(c):
if float32(c.Uint()) == e {
err = nil
}
case isFloat(c):
// Compare using float32 to avoid a false sense of precision; otherwise
// e.g. Equals(float32(0.1)) won't match float32(0.1).
if float32(c.Float()) == e {
err = nil
}
case isComplex(c):
comp := c.Complex()
rl := real(comp)
im := imag(comp)
// Compare using float32 to avoid a false sense of precision; otherwise
// e.g. Equals(float32(0.1)) won't match (0.1 + 0i).
if im == 0 && float32(rl) == e {
err = nil
}
default:
err = NewFatalError("which is not numeric")
}
return
}
func checkAgainstFloat64(e float64, c reflect.Value) (err error) {
err = errors.New("")
ck := c.Kind()
switch {
case isSignedInteger(c):
if float64(c.Int()) == e {
err = nil
}
case isUnsignedInteger(c):
if float64(c.Uint()) == e {
err = nil
}
// If the actual value is lower precision, turn the comparison around so we
// apply the low-precision rules. Otherwise, e.g. Equals(0.1) may not match
// float32(0.1).
case ck == reflect.Float32 || ck == reflect.Complex64:
return Equals(c.Interface()).Matches(e)
// Otherwise, compare with double precision.
case isFloat(c):
if c.Float() == e {
err = nil
}
case isComplex(c):
comp := c.Complex()
rl := real(comp)
im := imag(comp)
if im == 0 && rl == e {
err = nil
}
default:
err = NewFatalError("which is not numeric")
}
return
}
func checkAgainstComplex64(e complex64, c reflect.Value) (err error) {
err = errors.New("")
realPart := real(e)
imaginaryPart := imag(e)
switch {
case isInteger(c) || isFloat(c):
// If we have no imaginary part, then we should just compare against the
// real part. Otherwise, we can't be equal.
if imaginaryPart != 0 {
return
}
return checkAgainstFloat32(realPart, c)
case isComplex(c):
// Compare using complex64 to avoid a false sense of precision; otherwise
// e.g. Equals(0.1 + 0i) won't match float32(0.1).
if complex64(c.Complex()) == e {
err = nil
}
default:
err = NewFatalError("which is not numeric")
}
return
}
func checkAgainstComplex128(e complex128, c reflect.Value) (err error) {
err = errors.New("")
realPart := real(e)
imaginaryPart := imag(e)
switch {
case isInteger(c) || isFloat(c):
// If we have no imaginary part, then we should just compare against the
// real part. Otherwise, we can't be equal.
if imaginaryPart != 0 {
return
}
return checkAgainstFloat64(realPart, c)
case isComplex(c):
if c.Complex() == e {
err = nil
}
default:
err = NewFatalError("which is not numeric")
}
return
}
////////////////////////////////////////////////////////////////////////
// Other types
////////////////////////////////////////////////////////////////////////
func checkAgainstBool(e bool, c reflect.Value) (err error) {
if c.Kind() != reflect.Bool {
err = NewFatalError("which is not a bool")
return
}
err = errors.New("")
if c.Bool() == e {
err = nil
}
return
}
func checkAgainstChan(e reflect.Value, c reflect.Value) (err error) {
// Create a description of e's type, e.g. "chan int".
typeStr := fmt.Sprintf("%s %s", e.Type().ChanDir(), e.Type().Elem())
// Make sure c is a chan of the correct type.
if c.Kind() != reflect.Chan ||
c.Type().ChanDir() != e.Type().ChanDir() ||
c.Type().Elem() != e.Type().Elem() {
err = NewFatalError(fmt.Sprintf("which is not a %s", typeStr))
return
}
err = errors.New("")
if c.Pointer() == e.Pointer() {
err = nil
}
return
}
func checkAgainstFunc(e reflect.Value, c reflect.Value) (err error) {
// Make sure c is a function.
if c.Kind() != reflect.Func {
err = NewFatalError("which is not a function")
return
}
err = errors.New("")
if c.Pointer() == e.Pointer() {
err = nil
}
return
}
func checkAgainstMap(e reflect.Value, c reflect.Value) (err error) {
// Make sure c is a map.
if c.Kind() != reflect.Map {
err = NewFatalError("which is not a map")
return
}
err = errors.New("")
if c.Pointer() == e.Pointer() {
err = nil
}
return
}
func checkAgainstPtr(e reflect.Value, c reflect.Value) (err error) {
// Create a description of e's type, e.g. "*int".
typeStr := fmt.Sprintf("*%v", e.Type().Elem())
// Make sure c is a pointer of the correct type.
if c.Kind() != reflect.Ptr ||
c.Type().Elem() != e.Type().Elem() {
err = NewFatalError(fmt.Sprintf("which is not a %s", typeStr))
return
}
err = errors.New("")
if c.Pointer() == e.Pointer() {
err = nil
}
return
}
func checkAgainstSlice(e reflect.Value, c reflect.Value) (err error) {
// Create a description of e's type, e.g. "[]int".
typeStr := fmt.Sprintf("[]%v", e.Type().Elem())
// Make sure c is a slice of the correct type.
if c.Kind() != reflect.Slice ||
c.Type().Elem() != e.Type().Elem() {
err = NewFatalError(fmt.Sprintf("which is not a %s", typeStr))
return
}
err = errors.New("")
if c.Pointer() == e.Pointer() {
err = nil
}
return
}
func checkAgainstString(e reflect.Value, c reflect.Value) (err error) {
// Make sure c is a string.
if c.Kind() != reflect.String {
err = NewFatalError("which is not a string")
return
}
err = errors.New("")
if c.String() == e.String() {
err = nil
}
return
}
func checkAgainstArray(e reflect.Value, c reflect.Value) (err error) {
// Create a description of e's type, e.g. "[2]int".
typeStr := fmt.Sprintf("%v", e.Type())
// Make sure c is the correct type.
if c.Type() != e.Type() {
err = NewFatalError(fmt.Sprintf("which is not %s", typeStr))
return
}
// Check for equality.
if e.Interface() != c.Interface() {
err = errors.New("")
return
}
return
}
func checkAgainstUnsafePointer(e reflect.Value, c reflect.Value) (err error) {
// Make sure c is a pointer.
if c.Kind() != reflect.UnsafePointer {
err = NewFatalError("which is not a unsafe.Pointer")
return
}
err = errors.New("")
if c.Pointer() == e.Pointer() {
err = nil
}
return
}
func checkForNil(c reflect.Value) (err error) {
err = errors.New("")
// Make sure it is legal to call IsNil.
switch c.Kind() {
case reflect.Invalid:
case reflect.Chan:
case reflect.Func:
case reflect.Interface:
case reflect.Map:
case reflect.Ptr:
case reflect.Slice:
default:
err = NewFatalError("which cannot be compared to nil")
return
}
// Ask whether the value is nil. Handle a nil literal (kind Invalid)
// specially, since it's not legal to call IsNil there.
if c.Kind() == reflect.Invalid || c.IsNil() {
err = nil
}
return
}
////////////////////////////////////////////////////////////////////////
// Public implementation
////////////////////////////////////////////////////////////////////////
func (m *equalsMatcher) Matches(candidate interface{}) error {
e := m.expectedValue
c := reflect.ValueOf(candidate)
ek := e.Kind()
switch {
case ek == reflect.Bool:
return checkAgainstBool(e.Bool(), c)
case isSignedInteger(e):
return checkAgainstInt64(e.Int(), c)
case isUnsignedInteger(e):
return checkAgainstUint64(e.Uint(), c)
case ek == reflect.Float32:
return checkAgainstFloat32(float32(e.Float()), c)
case ek == reflect.Float64:
return checkAgainstFloat64(e.Float(), c)
case ek == reflect.Complex64:
return checkAgainstComplex64(complex64(e.Complex()), c)
case ek == reflect.Complex128:
return checkAgainstComplex128(complex128(e.Complex()), c)
case ek == reflect.Chan:
return checkAgainstChan(e, c)
case ek == reflect.Func:
return checkAgainstFunc(e, c)
case ek == reflect.Map:
return checkAgainstMap(e, c)
case ek == reflect.Ptr:
return checkAgainstPtr(e, c)
case ek == reflect.Slice:
return checkAgainstSlice(e, c)
case ek == reflect.String:
return checkAgainstString(e, c)
case ek == reflect.Array:
return checkAgainstArray(e, c)
case ek == reflect.UnsafePointer:
return checkAgainstUnsafePointer(e, c)
case ek == reflect.Invalid:
return checkForNil(c)
}
panic(fmt.Sprintf("equalsMatcher.Matches: unexpected kind: %v", ek))
}
func (m *equalsMatcher) Description() string {
// Special case: handle nil.
if !m.expectedValue.IsValid() {
return "is nil"
}
return fmt.Sprintf("%v", m.expectedValue.Interface())
}