377 lines
11 KiB
Go
377 lines
11 KiB
Go
// Copyright 2017, The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package cmp_test
|
|
|
|
import (
|
|
"fmt"
|
|
"math"
|
|
"net"
|
|
"reflect"
|
|
"sort"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/google/go-cmp/cmp"
|
|
)
|
|
|
|
// TODO: Re-write these examples in terms of how you actually use the
|
|
// fundamental options and filters and not in terms of what cool things you can
|
|
// do with them since that overlaps with cmp/cmpopts.
|
|
|
|
// Use Diff to print out a human-readable report of differences for tests
|
|
// comparing nested or structured data.
|
|
func ExampleDiff_testing() {
|
|
// Let got be the hypothetical value obtained from some logic under test
|
|
// and want be the expected golden data.
|
|
got, want := MakeGatewayInfo()
|
|
|
|
if diff := cmp.Diff(want, got); diff != "" {
|
|
t.Errorf("MakeGatewayInfo() mismatch (-want +got):\n%s", diff)
|
|
}
|
|
|
|
// Output:
|
|
// MakeGatewayInfo() mismatch (-want +got):
|
|
// cmp_test.Gateway{
|
|
// SSID: "CoffeeShopWiFi",
|
|
// - IPAddress: s"192.168.0.2",
|
|
// + IPAddress: s"192.168.0.1",
|
|
// NetMask: {0xff, 0xff, 0x00, 0x00},
|
|
// Clients: []cmp_test.Client{
|
|
// ... // 2 identical elements
|
|
// {Hostname: "macchiato", IPAddress: s"192.168.0.153", LastSeen: s"2009-11-10 23:39:43 +0000 UTC"},
|
|
// {Hostname: "espresso", IPAddress: s"192.168.0.121"},
|
|
// {
|
|
// Hostname: "latte",
|
|
// - IPAddress: s"192.168.0.221",
|
|
// + IPAddress: s"192.168.0.219",
|
|
// LastSeen: s"2009-11-10 23:00:23 +0000 UTC",
|
|
// },
|
|
// + {
|
|
// + Hostname: "americano",
|
|
// + IPAddress: s"192.168.0.188",
|
|
// + LastSeen: s"2009-11-10 23:03:05 +0000 UTC",
|
|
// + },
|
|
// },
|
|
// }
|
|
}
|
|
|
|
// Approximate equality for floats can be handled by defining a custom
|
|
// comparer on floats that determines two values to be equal if they are within
|
|
// some range of each other.
|
|
//
|
|
// This example is for demonstrative purposes; use cmpopts.EquateApprox instead.
|
|
func ExampleOption_approximateFloats() {
|
|
// This Comparer only operates on float64.
|
|
// To handle float32s, either define a similar function for that type
|
|
// or use a Transformer to convert float32s into float64s.
|
|
opt := cmp.Comparer(func(x, y float64) bool {
|
|
delta := math.Abs(x - y)
|
|
mean := math.Abs(x+y) / 2.0
|
|
return delta/mean < 0.00001
|
|
})
|
|
|
|
x := []float64{1.0, 1.1, 1.2, math.Pi}
|
|
y := []float64{1.0, 1.1, 1.2, 3.14159265359} // Accurate enough to Pi
|
|
z := []float64{1.0, 1.1, 1.2, 3.1415} // Diverges too far from Pi
|
|
|
|
fmt.Println(cmp.Equal(x, y, opt))
|
|
fmt.Println(cmp.Equal(y, z, opt))
|
|
fmt.Println(cmp.Equal(z, x, opt))
|
|
|
|
// Output:
|
|
// true
|
|
// false
|
|
// false
|
|
}
|
|
|
|
// Normal floating-point arithmetic defines == to be false when comparing
|
|
// NaN with itself. In certain cases, this is not the desired property.
|
|
//
|
|
// This example is for demonstrative purposes; use cmpopts.EquateNaNs instead.
|
|
func ExampleOption_equalNaNs() {
|
|
// This Comparer only operates on float64.
|
|
// To handle float32s, either define a similar function for that type
|
|
// or use a Transformer to convert float32s into float64s.
|
|
opt := cmp.Comparer(func(x, y float64) bool {
|
|
return (math.IsNaN(x) && math.IsNaN(y)) || x == y
|
|
})
|
|
|
|
x := []float64{1.0, math.NaN(), math.E, 0.0}
|
|
y := []float64{1.0, math.NaN(), math.E, 0.0}
|
|
z := []float64{1.0, math.NaN(), math.Pi, 0.0} // Pi constant instead of E
|
|
|
|
fmt.Println(cmp.Equal(x, y, opt))
|
|
fmt.Println(cmp.Equal(y, z, opt))
|
|
fmt.Println(cmp.Equal(z, x, opt))
|
|
|
|
// Output:
|
|
// true
|
|
// false
|
|
// false
|
|
}
|
|
|
|
// To have floating-point comparisons combine both properties of NaN being
|
|
// equal to itself and also approximate equality of values, filters are needed
|
|
// to restrict the scope of the comparison so that they are composable.
|
|
//
|
|
// This example is for demonstrative purposes;
|
|
// use cmpopts.EquateNaNs and cmpopts.EquateApprox instead.
|
|
func ExampleOption_equalNaNsAndApproximateFloats() {
|
|
alwaysEqual := cmp.Comparer(func(_, _ interface{}) bool { return true })
|
|
|
|
opts := cmp.Options{
|
|
// This option declares that a float64 comparison is equal only if
|
|
// both inputs are NaN.
|
|
cmp.FilterValues(func(x, y float64) bool {
|
|
return math.IsNaN(x) && math.IsNaN(y)
|
|
}, alwaysEqual),
|
|
|
|
// This option declares approximate equality on float64s only if
|
|
// both inputs are not NaN.
|
|
cmp.FilterValues(func(x, y float64) bool {
|
|
return !math.IsNaN(x) && !math.IsNaN(y)
|
|
}, cmp.Comparer(func(x, y float64) bool {
|
|
delta := math.Abs(x - y)
|
|
mean := math.Abs(x+y) / 2.0
|
|
return delta/mean < 0.00001
|
|
})),
|
|
}
|
|
|
|
x := []float64{math.NaN(), 1.0, 1.1, 1.2, math.Pi}
|
|
y := []float64{math.NaN(), 1.0, 1.1, 1.2, 3.14159265359} // Accurate enough to Pi
|
|
z := []float64{math.NaN(), 1.0, 1.1, 1.2, 3.1415} // Diverges too far from Pi
|
|
|
|
fmt.Println(cmp.Equal(x, y, opts))
|
|
fmt.Println(cmp.Equal(y, z, opts))
|
|
fmt.Println(cmp.Equal(z, x, opts))
|
|
|
|
// Output:
|
|
// true
|
|
// false
|
|
// false
|
|
}
|
|
|
|
// Sometimes, an empty map or slice is considered equal to an allocated one
|
|
// of zero length.
|
|
//
|
|
// This example is for demonstrative purposes; use cmpopts.EquateEmpty instead.
|
|
func ExampleOption_equalEmpty() {
|
|
alwaysEqual := cmp.Comparer(func(_, _ interface{}) bool { return true })
|
|
|
|
// This option handles slices and maps of any type.
|
|
opt := cmp.FilterValues(func(x, y interface{}) bool {
|
|
vx, vy := reflect.ValueOf(x), reflect.ValueOf(y)
|
|
return (vx.IsValid() && vy.IsValid() && vx.Type() == vy.Type()) &&
|
|
(vx.Kind() == reflect.Slice || vx.Kind() == reflect.Map) &&
|
|
(vx.Len() == 0 && vy.Len() == 0)
|
|
}, alwaysEqual)
|
|
|
|
type S struct {
|
|
A []int
|
|
B map[string]bool
|
|
}
|
|
x := S{nil, make(map[string]bool, 100)}
|
|
y := S{make([]int, 0, 200), nil}
|
|
z := S{[]int{0}, nil} // []int has a single element (i.e., not empty)
|
|
|
|
fmt.Println(cmp.Equal(x, y, opt))
|
|
fmt.Println(cmp.Equal(y, z, opt))
|
|
fmt.Println(cmp.Equal(z, x, opt))
|
|
|
|
// Output:
|
|
// true
|
|
// false
|
|
// false
|
|
}
|
|
|
|
// Two slices may be considered equal if they have the same elements,
|
|
// regardless of the order that they appear in. Transformations can be used
|
|
// to sort the slice.
|
|
//
|
|
// This example is for demonstrative purposes; use cmpopts.SortSlices instead.
|
|
func ExampleOption_sortedSlice() {
|
|
// This Transformer sorts a []int.
|
|
trans := cmp.Transformer("Sort", func(in []int) []int {
|
|
out := append([]int(nil), in...) // Copy input to avoid mutating it
|
|
sort.Ints(out)
|
|
return out
|
|
})
|
|
|
|
x := struct{ Ints []int }{[]int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}}
|
|
y := struct{ Ints []int }{[]int{2, 8, 0, 9, 6, 1, 4, 7, 3, 5}}
|
|
z := struct{ Ints []int }{[]int{0, 0, 1, 2, 3, 4, 5, 6, 7, 8}}
|
|
|
|
fmt.Println(cmp.Equal(x, y, trans))
|
|
fmt.Println(cmp.Equal(y, z, trans))
|
|
fmt.Println(cmp.Equal(z, x, trans))
|
|
|
|
// Output:
|
|
// true
|
|
// false
|
|
// false
|
|
}
|
|
|
|
type otherString string
|
|
|
|
func (x otherString) Equal(y otherString) bool {
|
|
return strings.EqualFold(string(x), string(y))
|
|
}
|
|
|
|
// If the Equal method defined on a type is not suitable, the type can be
|
|
// dynamically transformed to be stripped of the Equal method (or any method
|
|
// for that matter).
|
|
func ExampleOption_avoidEqualMethod() {
|
|
// Suppose otherString.Equal performs a case-insensitive equality,
|
|
// which is too loose for our needs.
|
|
// We can avoid the methods of otherString by declaring a new type.
|
|
type myString otherString
|
|
|
|
// This transformer converts otherString to myString, allowing Equal to use
|
|
// other Options to determine equality.
|
|
trans := cmp.Transformer("", func(in otherString) myString {
|
|
return myString(in)
|
|
})
|
|
|
|
x := []otherString{"foo", "bar", "baz"}
|
|
y := []otherString{"fOO", "bAr", "Baz"} // Same as before, but with different case
|
|
|
|
fmt.Println(cmp.Equal(x, y)) // Equal because of case-insensitivity
|
|
fmt.Println(cmp.Equal(x, y, trans)) // Not equal because of more exact equality
|
|
|
|
// Output:
|
|
// true
|
|
// false
|
|
}
|
|
|
|
func roundF64(z float64) float64 {
|
|
if z < 0 {
|
|
return math.Ceil(z - 0.5)
|
|
}
|
|
return math.Floor(z + 0.5)
|
|
}
|
|
|
|
// The complex numbers complex64 and complex128 can really just be decomposed
|
|
// into a pair of float32 or float64 values. It would be convenient to be able
|
|
// define only a single comparator on float64 and have float32, complex64, and
|
|
// complex128 all be able to use that comparator. Transformations can be used
|
|
// to handle this.
|
|
func ExampleOption_transformComplex() {
|
|
opts := []cmp.Option{
|
|
// This transformer decomposes complex128 into a pair of float64s.
|
|
cmp.Transformer("T1", func(in complex128) (out struct{ Real, Imag float64 }) {
|
|
out.Real, out.Imag = real(in), imag(in)
|
|
return out
|
|
}),
|
|
// This transformer converts complex64 to complex128 to allow the
|
|
// above transform to take effect.
|
|
cmp.Transformer("T2", func(in complex64) complex128 {
|
|
return complex128(in)
|
|
}),
|
|
// This transformer converts float32 to float64.
|
|
cmp.Transformer("T3", func(in float32) float64 {
|
|
return float64(in)
|
|
}),
|
|
// This equality function compares float64s as rounded integers.
|
|
cmp.Comparer(func(x, y float64) bool {
|
|
return roundF64(x) == roundF64(y)
|
|
}),
|
|
}
|
|
|
|
x := []interface{}{
|
|
complex128(3.0), complex64(5.1 + 2.9i), float32(-1.2), float64(12.3),
|
|
}
|
|
y := []interface{}{
|
|
complex128(3.1), complex64(4.9 + 3.1i), float32(-1.3), float64(11.7),
|
|
}
|
|
z := []interface{}{
|
|
complex128(3.8), complex64(4.9 + 3.1i), float32(-1.3), float64(11.7),
|
|
}
|
|
|
|
fmt.Println(cmp.Equal(x, y, opts...))
|
|
fmt.Println(cmp.Equal(y, z, opts...))
|
|
fmt.Println(cmp.Equal(z, x, opts...))
|
|
|
|
// Output:
|
|
// true
|
|
// false
|
|
// false
|
|
}
|
|
|
|
type (
|
|
Gateway struct {
|
|
SSID string
|
|
IPAddress net.IP
|
|
NetMask net.IPMask
|
|
Clients []Client
|
|
}
|
|
Client struct {
|
|
Hostname string
|
|
IPAddress net.IP
|
|
LastSeen time.Time
|
|
}
|
|
)
|
|
|
|
func MakeGatewayInfo() (x, y Gateway) {
|
|
x = Gateway{
|
|
SSID: "CoffeeShopWiFi",
|
|
IPAddress: net.IPv4(192, 168, 0, 1),
|
|
NetMask: net.IPv4Mask(255, 255, 0, 0),
|
|
Clients: []Client{{
|
|
Hostname: "ristretto",
|
|
IPAddress: net.IPv4(192, 168, 0, 116),
|
|
}, {
|
|
Hostname: "aribica",
|
|
IPAddress: net.IPv4(192, 168, 0, 104),
|
|
LastSeen: time.Date(2009, time.November, 10, 23, 6, 32, 0, time.UTC),
|
|
}, {
|
|
Hostname: "macchiato",
|
|
IPAddress: net.IPv4(192, 168, 0, 153),
|
|
LastSeen: time.Date(2009, time.November, 10, 23, 39, 43, 0, time.UTC),
|
|
}, {
|
|
Hostname: "espresso",
|
|
IPAddress: net.IPv4(192, 168, 0, 121),
|
|
}, {
|
|
Hostname: "latte",
|
|
IPAddress: net.IPv4(192, 168, 0, 219),
|
|
LastSeen: time.Date(2009, time.November, 10, 23, 0, 23, 0, time.UTC),
|
|
}, {
|
|
Hostname: "americano",
|
|
IPAddress: net.IPv4(192, 168, 0, 188),
|
|
LastSeen: time.Date(2009, time.November, 10, 23, 3, 5, 0, time.UTC),
|
|
}},
|
|
}
|
|
y = Gateway{
|
|
SSID: "CoffeeShopWiFi",
|
|
IPAddress: net.IPv4(192, 168, 0, 2),
|
|
NetMask: net.IPv4Mask(255, 255, 0, 0),
|
|
Clients: []Client{{
|
|
Hostname: "ristretto",
|
|
IPAddress: net.IPv4(192, 168, 0, 116),
|
|
}, {
|
|
Hostname: "aribica",
|
|
IPAddress: net.IPv4(192, 168, 0, 104),
|
|
LastSeen: time.Date(2009, time.November, 10, 23, 6, 32, 0, time.UTC),
|
|
}, {
|
|
Hostname: "macchiato",
|
|
IPAddress: net.IPv4(192, 168, 0, 153),
|
|
LastSeen: time.Date(2009, time.November, 10, 23, 39, 43, 0, time.UTC),
|
|
}, {
|
|
Hostname: "espresso",
|
|
IPAddress: net.IPv4(192, 168, 0, 121),
|
|
}, {
|
|
Hostname: "latte",
|
|
IPAddress: net.IPv4(192, 168, 0, 221),
|
|
LastSeen: time.Date(2009, time.November, 10, 23, 0, 23, 0, time.UTC),
|
|
}},
|
|
}
|
|
return x, y
|
|
}
|
|
|
|
var t fakeT
|
|
|
|
type fakeT struct{}
|
|
|
|
func (t fakeT) Errorf(format string, args ...interface{}) { fmt.Printf(format+"\n", args...) }
|