diff options
Diffstat (limited to 'vendor/github.com/google/go-cmp/cmp/cmpopts/equate.go')
| -rw-r--r-- | vendor/github.com/google/go-cmp/cmp/cmpopts/equate.go | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/vendor/github.com/google/go-cmp/cmp/cmpopts/equate.go b/vendor/github.com/google/go-cmp/cmp/cmpopts/equate.go new file mode 100644 index 0000000..3d8d0cd --- /dev/null +++ b/vendor/github.com/google/go-cmp/cmp/cmpopts/equate.go @@ -0,0 +1,185 @@ +// 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 cmpopts provides common options for the cmp package. +package cmpopts + +import ( + "errors" + "fmt" + "math" + "reflect" + "time" + + "github.com/google/go-cmp/cmp" +) + +func equateAlways(_, _ interface{}) bool { return true } + +// EquateEmpty returns a [cmp.Comparer] option that determines all maps and slices +// with a length of zero to be equal, regardless of whether they are nil. +// +// EquateEmpty can be used in conjunction with [SortSlices] and [SortMaps]. +func EquateEmpty() cmp.Option { + return cmp.FilterValues(isEmpty, cmp.Comparer(equateAlways)) +} + +func isEmpty(x, y interface{}) bool { + vx, vy := reflect.ValueOf(x), reflect.ValueOf(y) + return (x != nil && y != nil && vx.Type() == vy.Type()) && + (vx.Kind() == reflect.Slice || vx.Kind() == reflect.Map) && + (vx.Len() == 0 && vy.Len() == 0) +} + +// EquateApprox returns a [cmp.Comparer] option that determines float32 or float64 +// values to be equal if they are within a relative fraction or absolute margin. +// This option is not used when either x or y is NaN or infinite. +// +// The fraction determines that the difference of two values must be within the +// smaller fraction of the two values, while the margin determines that the two +// values must be within some absolute margin. +// To express only a fraction or only a margin, use 0 for the other parameter. +// The fraction and margin must be non-negative. +// +// The mathematical expression used is equivalent to: +// +// |x-y| ≤ max(fraction*min(|x|, |y|), margin) +// +// EquateApprox can be used in conjunction with [EquateNaNs]. +func EquateApprox(fraction, margin float64) cmp.Option { + if margin < 0 || fraction < 0 || math.IsNaN(margin) || math.IsNaN(fraction) { + panic("margin or fraction must be a non-negative number") + } + a := approximator{fraction, margin} + return cmp.Options{ + cmp.FilterValues(areRealF64s, cmp.Comparer(a.compareF64)), + cmp.FilterValues(areRealF32s, cmp.Comparer(a.compareF32)), + } +} + +type approximator struct{ frac, marg float64 } + +func areRealF64s(x, y float64) bool { + return !math.IsNaN(x) && !math.IsNaN(y) && !math.IsInf(x, 0) && !math.IsInf(y, 0) +} +func areRealF32s(x, y float32) bool { + return areRealF64s(float64(x), float64(y)) +} +func (a approximator) compareF64(x, y float64) bool { + relMarg := a.frac * math.Min(math.Abs(x), math.Abs(y)) + return math.Abs(x-y) <= math.Max(a.marg, relMarg) +} +func (a approximator) compareF32(x, y float32) bool { + return a.compareF64(float64(x), float64(y)) +} + +// EquateNaNs returns a [cmp.Comparer] option that determines float32 and float64 +// NaN values to be equal. +// +// EquateNaNs can be used in conjunction with [EquateApprox]. +func EquateNaNs() cmp.Option { + return cmp.Options{ + cmp.FilterValues(areNaNsF64s, cmp.Comparer(equateAlways)), + cmp.FilterValues(areNaNsF32s, cmp.Comparer(equateAlways)), + } +} + +func areNaNsF64s(x, y float64) bool { + return math.IsNaN(x) && math.IsNaN(y) +} +func areNaNsF32s(x, y float32) bool { + return areNaNsF64s(float64(x), float64(y)) +} + +// EquateApproxTime returns a [cmp.Comparer] option that determines two non-zero +// [time.Time] values to be equal if they are within some margin of one another. +// If both times have a monotonic clock reading, then the monotonic time +// difference will be used. The margin must be non-negative. +func EquateApproxTime(margin time.Duration) cmp.Option { + if margin < 0 { + panic("margin must be a non-negative number") + } + a := timeApproximator{margin} + return cmp.FilterValues(areNonZeroTimes, cmp.Comparer(a.compare)) +} + +func areNonZeroTimes(x, y time.Time) bool { + return !x.IsZero() && !y.IsZero() +} + +type timeApproximator struct { + margin time.Duration +} + +func (a timeApproximator) compare(x, y time.Time) bool { + // Avoid subtracting times to avoid overflow when the + // difference is larger than the largest representable duration. + if x.After(y) { + // Ensure x is always before y + x, y = y, x + } + // We're within the margin if x+margin >= y. + // Note: time.Time doesn't have AfterOrEqual method hence the negation. + return !x.Add(a.margin).Before(y) +} + +// AnyError is an error that matches any non-nil error. +var AnyError anyError + +type anyError struct{} + +func (anyError) Error() string { return "any error" } +func (anyError) Is(err error) bool { return err != nil } + +// EquateErrors returns a [cmp.Comparer] option that determines errors to be equal +// if [errors.Is] reports them to match. The [AnyError] error can be used to +// match any non-nil error. +func EquateErrors() cmp.Option { + return cmp.FilterValues(areConcreteErrors, cmp.Comparer(compareErrors)) +} + +// areConcreteErrors reports whether x and y are types that implement error. +// The input types are deliberately of the interface{} type rather than the +// error type so that we can handle situations where the current type is an +// interface{}, but the underlying concrete types both happen to implement +// the error interface. +func areConcreteErrors(x, y interface{}) bool { + _, ok1 := x.(error) + _, ok2 := y.(error) + return ok1 && ok2 +} + +func compareErrors(x, y interface{}) bool { + xe := x.(error) + ye := y.(error) + return errors.Is(xe, ye) || errors.Is(ye, xe) +} + +// EquateComparable returns a [cmp.Option] that determines equality +// of comparable types by directly comparing them using the == operator in Go. +// The types to compare are specified by passing a value of that type. +// This option should only be used on types that are documented as being +// safe for direct == comparison. For example, [net/netip.Addr] is documented +// as being semantically safe to use with ==, while [time.Time] is documented +// to discourage the use of == on time values. +func EquateComparable(typs ...interface{}) cmp.Option { + types := make(typesFilter) + for _, typ := range typs { + switch t := reflect.TypeOf(typ); { + case !t.Comparable(): + panic(fmt.Sprintf("%T is not a comparable Go type", typ)) + case types[t]: + panic(fmt.Sprintf("%T is already specified", typ)) + default: + types[t] = true + } + } + return cmp.FilterPath(types.filter, cmp.Comparer(equateAny)) +} + +type typesFilter map[reflect.Type]bool + +func (tf typesFilter) filter(p cmp.Path) bool { return tf[p.Last().Type()] } + +func equateAny(x, y interface{}) bool { return x == y } |
