433 lines
13 KiB
Go
433 lines
13 KiB
Go
|
// Copyright 2019, 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.md file.
|
||
|
|
|
||
|
|
package cmp
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"reflect"
|
||
|
|
|
||
|
|
"github.com/google/go-cmp/cmp/internal/value"
|
||
|
|
)
|
||
|
|
|
||
|
|
// numContextRecords is the number of surrounding equal records to print.
|
||
|
|
const numContextRecords = 2
|
||
|
|
|
||
|
|
type diffMode byte
|
||
|
|
|
||
|
|
const (
|
||
|
|
diffUnknown diffMode = 0
|
||
|
|
diffIdentical diffMode = ' '
|
||
|
|
diffRemoved diffMode = '-'
|
||
|
|
diffInserted diffMode = '+'
|
||
|
|
)
|
||
|
|
|
||
|
|
type typeMode int
|
||
|
|
|
||
|
|
const (
|
||
|
|
// emitType always prints the type.
|
||
|
|
emitType typeMode = iota
|
||
|
|
// elideType never prints the type.
|
||
|
|
elideType
|
||
|
|
// autoType prints the type only for composite kinds
|
||
|
|
// (i.e., structs, slices, arrays, and maps).
|
||
|
|
autoType
|
||
|
|
)
|
||
|
|
|
||
|
|
type formatOptions struct {
|
||
|
|
// DiffMode controls the output mode of FormatDiff.
|
||
|
|
//
|
||
|
|
// If diffUnknown, then produce a diff of the x and y values.
|
||
|
|
// If diffIdentical, then emit values as if they were equal.
|
||
|
|
// If diffRemoved, then only emit x values (ignoring y values).
|
||
|
|
// If diffInserted, then only emit y values (ignoring x values).
|
||
|
|
DiffMode diffMode
|
||
|
|
|
||
|
|
// TypeMode controls whether to print the type for the current node.
|
||
|
|
//
|
||
|
|
// As a general rule of thumb, we always print the type of the next node
|
||
|
|
// after an interface, and always elide the type of the next node after
|
||
|
|
// a slice or map node.
|
||
|
|
TypeMode typeMode
|
||
|
|
|
||
|
|
// formatValueOptions are options specific to printing reflect.Values.
|
||
|
|
formatValueOptions
|
||
|
|
}
|
||
|
|
|
||
|
|
func (opts formatOptions) WithDiffMode(d diffMode) formatOptions {
|
||
|
|
opts.DiffMode = d
|
||
|
|
return opts
|
||
|
|
}
|
||
|
|
func (opts formatOptions) WithTypeMode(t typeMode) formatOptions {
|
||
|
|
opts.TypeMode = t
|
||
|
|
return opts
|
||
|
|
}
|
||
|
|
func (opts formatOptions) WithVerbosity(level int) formatOptions {
|
||
|
|
opts.VerbosityLevel = level
|
||
|
|
opts.LimitVerbosity = true
|
||
|
|
return opts
|
||
|
|
}
|
||
|
|
func (opts formatOptions) verbosity() uint {
|
||
|
|
switch {
|
||
|
|
case opts.VerbosityLevel < 0:
|
||
|
|
return 0
|
||
|
|
case opts.VerbosityLevel > 16:
|
||
|
|
return 16 // some reasonable maximum to avoid shift overflow
|
||
|
|
default:
|
||
|
|
return uint(opts.VerbosityLevel)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
const maxVerbosityPreset = 3
|
||
|
|
|
||
|
|
// verbosityPreset modifies the verbosity settings given an index
|
||
|
|
// between 0 and maxVerbosityPreset, inclusive.
|
||
|
|
func verbosityPreset(opts formatOptions, i int) formatOptions {
|
||
|
|
opts.VerbosityLevel = int(opts.verbosity()) + 2*i
|
||
|
|
if i > 0 {
|
||
|
|
opts.AvoidStringer = true
|
||
|
|
}
|
||
|
|
if i >= maxVerbosityPreset {
|
||
|
|
opts.PrintAddresses = true
|
||
|
|
opts.QualifiedNames = true
|
||
|
|
}
|
||
|
|
return opts
|
||
|
|
}
|
||
|
|
|
||
|
|
// FormatDiff converts a valueNode tree into a textNode tree, where the later
|
||
|
|
// is a textual representation of the differences detected in the former.
|
||
|
|
func (opts formatOptions) FormatDiff(v *valueNode, ptrs *pointerReferences) (out textNode) {
|
||
|
|
if opts.DiffMode == diffIdentical {
|
||
|
|
opts = opts.WithVerbosity(1)
|
||
|
|
} else {
|
||
|
|
opts = opts.WithVerbosity(3)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Check whether we have specialized formatting for this node.
|
||
|
|
// This is not necessary, but helpful for producing more readable outputs.
|
||
|
|
if opts.CanFormatDiffSlice(v) {
|
||
|
|
return opts.FormatDiffSlice(v)
|
||
|
|
}
|
||
|
|
|
||
|
|
var parentKind reflect.Kind
|
||
|
|
if v.parent != nil && v.parent.TransformerName == "" {
|
||
|
|
parentKind = v.parent.Type.Kind()
|
||
|
|
}
|
||
|
|
|
||
|
|
// For leaf nodes, format the value based on the reflect.Values alone.
|
||
|
|
if v.MaxDepth == 0 {
|
||
|
|
switch opts.DiffMode {
|
||
|
|
case diffUnknown, diffIdentical:
|
||
|
|
// Format Equal.
|
||
|
|
if v.NumDiff == 0 {
|
||
|
|
outx := opts.FormatValue(v.ValueX, parentKind, ptrs)
|
||
|
|
outy := opts.FormatValue(v.ValueY, parentKind, ptrs)
|
||
|
|
if v.NumIgnored > 0 && v.NumSame == 0 {
|
||
|
|
return textEllipsis
|
||
|
|
} else if outx.Len() < outy.Len() {
|
||
|
|
return outx
|
||
|
|
} else {
|
||
|
|
return outy
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Format unequal.
|
||
|
|
assert(opts.DiffMode == diffUnknown)
|
||
|
|
var list textList
|
||
|
|
outx := opts.WithTypeMode(elideType).FormatValue(v.ValueX, parentKind, ptrs)
|
||
|
|
outy := opts.WithTypeMode(elideType).FormatValue(v.ValueY, parentKind, ptrs)
|
||
|
|
for i := 0; i <= maxVerbosityPreset && outx != nil && outy != nil && outx.Equal(outy); i++ {
|
||
|
|
opts2 := verbosityPreset(opts, i).WithTypeMode(elideType)
|
||
|
|
outx = opts2.FormatValue(v.ValueX, parentKind, ptrs)
|
||
|
|
outy = opts2.FormatValue(v.ValueY, parentKind, ptrs)
|
||
|
|
}
|
||
|
|
if outx != nil {
|
||
|
|
list = append(list, textRecord{Diff: '-', Value: outx})
|
||
|
|
}
|
||
|
|
if outy != nil {
|
||
|
|
list = append(list, textRecord{Diff: '+', Value: outy})
|
||
|
|
}
|
||
|
|
return opts.WithTypeMode(emitType).FormatType(v.Type, list)
|
||
|
|
case diffRemoved:
|
||
|
|
return opts.FormatValue(v.ValueX, parentKind, ptrs)
|
||
|
|
case diffInserted:
|
||
|
|
return opts.FormatValue(v.ValueY, parentKind, ptrs)
|
||
|
|
default:
|
||
|
|
panic("invalid diff mode")
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Register slice element to support cycle detection.
|
||
|
|
if parentKind == reflect.Slice {
|
||
|
|
ptrRefs := ptrs.PushPair(v.ValueX, v.ValueY, opts.DiffMode, true)
|
||
|
|
defer ptrs.Pop()
|
||
|
|
defer func() { out = wrapTrunkReferences(ptrRefs, out) }()
|
||
|
|
}
|
||
|
|
|
||
|
|
// Descend into the child value node.
|
||
|
|
if v.TransformerName != "" {
|
||
|
|
out := opts.WithTypeMode(emitType).FormatDiff(v.Value, ptrs)
|
||
|
|
out = &textWrap{Prefix: "Inverse(" + v.TransformerName + ", ", Value: out, Suffix: ")"}
|
||
|
|
return opts.FormatType(v.Type, out)
|
||
|
|
} else {
|
||
|
|
switch k := v.Type.Kind(); k {
|
||
|
|
case reflect.Struct, reflect.Array, reflect.Slice:
|
||
|
|
out = opts.formatDiffList(v.Records, k, ptrs)
|
||
|
|
out = opts.FormatType(v.Type, out)
|
||
|
|
case reflect.Map:
|
||
|
|
// Register map to support cycle detection.
|
||
|
|
ptrRefs := ptrs.PushPair(v.ValueX, v.ValueY, opts.DiffMode, false)
|
||
|
|
defer ptrs.Pop()
|
||
|
|
|
||
|
|
out = opts.formatDiffList(v.Records, k, ptrs)
|
||
|
|
out = wrapTrunkReferences(ptrRefs, out)
|
||
|
|
out = opts.FormatType(v.Type, out)
|
||
|
|
case reflect.Ptr:
|
||
|
|
// Register pointer to support cycle detection.
|
||
|
|
ptrRefs := ptrs.PushPair(v.ValueX, v.ValueY, opts.DiffMode, false)
|
||
|
|
defer ptrs.Pop()
|
||
|
|
|
||
|
|
out = opts.FormatDiff(v.Value, ptrs)
|
||
|
|
out = wrapTrunkReferences(ptrRefs, out)
|
||
|
|
out = &textWrap{Prefix: "&", Value: out}
|
||
|
|
case reflect.Interface:
|
||
|
|
out = opts.WithTypeMode(emitType).FormatDiff(v.Value, ptrs)
|
||
|
|
default:
|
||
|
|
panic(fmt.Sprintf("%v cannot have children", k))
|
||
|
|
}
|
||
|
|
return out
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func (opts formatOptions) formatDiffList(recs []reportRecord, k reflect.Kind, ptrs *pointerReferences) textNode {
|
||
|
|
// Derive record name based on the data structure kind.
|
||
|
|
var name string
|
||
|
|
var formatKey func(reflect.Value) string
|
||
|
|
switch k {
|
||
|
|
case reflect.Struct:
|
||
|
|
name = "field"
|
||
|
|
opts = opts.WithTypeMode(autoType)
|
||
|
|
formatKey = func(v reflect.Value) string { return v.String() }
|
||
|
|
case reflect.Slice, reflect.Array:
|
||
|
|
name = "element"
|
||
|
|
opts = opts.WithTypeMode(elideType)
|
||
|
|
formatKey = func(reflect.Value) string { return "" }
|
||
|
|
case reflect.Map:
|
||
|
|
name = "entry"
|
||
|
|
opts = opts.WithTypeMode(elideType)
|
||
|
|
formatKey = func(v reflect.Value) string { return formatMapKey(v, false, ptrs) }
|
||
|
|
}
|
||
|
|
|
||
|
|
maxLen := -1
|
||
|
|
if opts.LimitVerbosity {
|
||
|
|
if opts.DiffMode == diffIdentical {
|
||
|
|
maxLen = ((1 << opts.verbosity()) >> 1) << 2 // 0, 4, 8, 16, 32, etc...
|
||
|
|
} else {
|
||
|
|
maxLen = (1 << opts.verbosity()) << 1 // 2, 4, 8, 16, 32, 64, etc...
|
||
|
|
}
|
||
|
|
opts.VerbosityLevel--
|
||
|
|
}
|
||
|
|
|
||
|
|
// Handle unification.
|
||
|
|
switch opts.DiffMode {
|
||
|
|
case diffIdentical, diffRemoved, diffInserted:
|
||
|
|
var list textList
|
||
|
|
var deferredEllipsis bool // Add final "..." to indicate records were dropped
|
||
|
|
for _, r := range recs {
|
||
|
|
if len(list) == maxLen {
|
||
|
|
deferredEllipsis = true
|
||
|
|
break
|
||
|
|
}
|
||
|
|
|
||
|
|
// Elide struct fields that are zero value.
|
||
|
|
if k == reflect.Struct {
|
||
|
|
var isZero bool
|
||
|
|
switch opts.DiffMode {
|
||
|
|
case diffIdentical:
|
||
|
|
isZero = value.IsZero(r.Value.ValueX) || value.IsZero(r.Value.ValueY)
|
||
|
|
case diffRemoved:
|
||
|
|
isZero = value.IsZero(r.Value.ValueX)
|
||
|
|
case diffInserted:
|
||
|
|
isZero = value.IsZero(r.Value.ValueY)
|
||
|
|
}
|
||
|
|
if isZero {
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// Elide ignored nodes.
|
||
|
|
if r.Value.NumIgnored > 0 && r.Value.NumSame+r.Value.NumDiff == 0 {
|
||
|
|
deferredEllipsis = !(k == reflect.Slice || k == reflect.Array)
|
||
|
|
if !deferredEllipsis {
|
||
|
|
list.AppendEllipsis(diffStats{})
|
||
|
|
}
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
if out := opts.FormatDiff(r.Value, ptrs); out != nil {
|
||
|
|
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if deferredEllipsis {
|
||
|
|
list.AppendEllipsis(diffStats{})
|
||
|
|
}
|
||
|
|
return &textWrap{Prefix: "{", Value: list, Suffix: "}"}
|
||
|
|
case diffUnknown:
|
||
|
|
default:
|
||
|
|
panic("invalid diff mode")
|
||
|
|
}
|
||
|
|
|
||
|
|
// Handle differencing.
|
||
|
|
var numDiffs int
|
||
|
|
var list textList
|
||
|
|
var keys []reflect.Value // invariant: len(list) == len(keys)
|
||
|
|
groups := coalesceAdjacentRecords(name, recs)
|
||
|
|
maxGroup := diffStats{Name: name}
|
||
|
|
for i, ds := range groups {
|
||
|
|
if maxLen >= 0 && numDiffs >= maxLen {
|
||
|
|
maxGroup = maxGroup.Append(ds)
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
// Handle equal records.
|
||
|
|
if ds.NumDiff() == 0 {
|
||
|
|
// Compute the number of leading and trailing records to print.
|
||
|
|
var numLo, numHi int
|
||
|
|
numEqual := ds.NumIgnored + ds.NumIdentical
|
||
|
|
for numLo < numContextRecords && numLo+numHi < numEqual && i != 0 {
|
||
|
|
if r := recs[numLo].Value; r.NumIgnored > 0 && r.NumSame+r.NumDiff == 0 {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
numLo++
|
||
|
|
}
|
||
|
|
for numHi < numContextRecords && numLo+numHi < numEqual && i != len(groups)-1 {
|
||
|
|
if r := recs[numEqual-numHi-1].Value; r.NumIgnored > 0 && r.NumSame+r.NumDiff == 0 {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
numHi++
|
||
|
|
}
|
||
|
|
if numEqual-(numLo+numHi) == 1 && ds.NumIgnored == 0 {
|
||
|
|
numHi++ // Avoid pointless coalescing of a single equal record
|
||
|
|
}
|
||
|
|
|
||
|
|
// Format the equal values.
|
||
|
|
for _, r := range recs[:numLo] {
|
||
|
|
out := opts.WithDiffMode(diffIdentical).FormatDiff(r.Value, ptrs)
|
||
|
|
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
|
||
|
|
keys = append(keys, r.Key)
|
||
|
|
}
|
||
|
|
if numEqual > numLo+numHi {
|
||
|
|
ds.NumIdentical -= numLo + numHi
|
||
|
|
list.AppendEllipsis(ds)
|
||
|
|
for len(keys) < len(list) {
|
||
|
|
keys = append(keys, reflect.Value{})
|
||
|
|
}
|
||
|
|
}
|
||
|
|
for _, r := range recs[numEqual-numHi : numEqual] {
|
||
|
|
out := opts.WithDiffMode(diffIdentical).FormatDiff(r.Value, ptrs)
|
||
|
|
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
|
||
|
|
keys = append(keys, r.Key)
|
||
|
|
}
|
||
|
|
recs = recs[numEqual:]
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
// Handle unequal records.
|
||
|
|
for _, r := range recs[:ds.NumDiff()] {
|
||
|
|
switch {
|
||
|
|
case opts.CanFormatDiffSlice(r.Value):
|
||
|
|
out := opts.FormatDiffSlice(r.Value)
|
||
|
|
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
|
||
|
|
keys = append(keys, r.Key)
|
||
|
|
case r.Value.NumChildren == r.Value.MaxDepth:
|
||
|
|
outx := opts.WithDiffMode(diffRemoved).FormatDiff(r.Value, ptrs)
|
||
|
|
outy := opts.WithDiffMode(diffInserted).FormatDiff(r.Value, ptrs)
|
||
|
|
for i := 0; i <= maxVerbosityPreset && outx != nil && outy != nil && outx.Equal(outy); i++ {
|
||
|
|
opts2 := verbosityPreset(opts, i)
|
||
|
|
outx = opts2.WithDiffMode(diffRemoved).FormatDiff(r.Value, ptrs)
|
||
|
|
outy = opts2.WithDiffMode(diffInserted).FormatDiff(r.Value, ptrs)
|
||
|
|
}
|
||
|
|
if outx != nil {
|
||
|
|
list = append(list, textRecord{Diff: diffRemoved, Key: formatKey(r.Key), Value: outx})
|
||
|
|
keys = append(keys, r.Key)
|
||
|
|
}
|
||
|
|
if outy != nil {
|
||
|
|
list = append(list, textRecord{Diff: diffInserted, Key: formatKey(r.Key), Value: outy})
|
||
|
|
keys = append(keys, r.Key)
|
||
|
|
}
|
||
|
|
default:
|
||
|
|
out := opts.FormatDiff(r.Value, ptrs)
|
||
|
|
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
|
||
|
|
keys = append(keys, r.Key)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
recs = recs[ds.NumDiff():]
|
||
|
|
numDiffs += ds.NumDiff()
|
||
|
|
}
|
||
|
|
if maxGroup.IsZero() {
|
||
|
|
assert(len(recs) == 0)
|
||
|
|
} else {
|
||
|
|
list.AppendEllipsis(maxGroup)
|
||
|
|
for len(keys) < len(list) {
|
||
|
|
keys = append(keys, reflect.Value{})
|
||
|
|
}
|
||
|
|
}
|
||
|
|
assert(len(list) == len(keys))
|
||
|
|
|
||
|
|
// For maps, the default formatting logic uses fmt.Stringer which may
|
||
|
|
// produce ambiguous output. Avoid calling String to disambiguate.
|
||
|
|
if k == reflect.Map {
|
||
|
|
var ambiguous bool
|
||
|
|
seenKeys := map[string]reflect.Value{}
|
||
|
|
for i, currKey := range keys {
|
||
|
|
if currKey.IsValid() {
|
||
|
|
strKey := list[i].Key
|
||
|
|
prevKey, seen := seenKeys[strKey]
|
||
|
|
if seen && prevKey.CanInterface() && currKey.CanInterface() {
|
||
|
|
ambiguous = prevKey.Interface() != currKey.Interface()
|
||
|
|
if ambiguous {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
seenKeys[strKey] = currKey
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if ambiguous {
|
||
|
|
for i, k := range keys {
|
||
|
|
if k.IsValid() {
|
||
|
|
list[i].Key = formatMapKey(k, true, ptrs)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return &textWrap{Prefix: "{", Value: list, Suffix: "}"}
|
||
|
|
}
|
||
|
|
|
||
|
|
// coalesceAdjacentRecords coalesces the list of records into groups of
|
||
|
|
// adjacent equal, or unequal counts.
|
||
|
|
func coalesceAdjacentRecords(name string, recs []reportRecord) (groups []diffStats) {
|
||
|
|
var prevCase int // Arbitrary index into which case last occurred
|
||
|
|
lastStats := func(i int) *diffStats {
|
||
|
|
if prevCase != i {
|
||
|
|
groups = append(groups, diffStats{Name: name})
|
||
|
|
prevCase = i
|
||
|
|
}
|
||
|
|
return &groups[len(groups)-1]
|
||
|
|
}
|
||
|
|
for _, r := range recs {
|
||
|
|
switch rv := r.Value; {
|
||
|
|
case rv.NumIgnored > 0 && rv.NumSame+rv.NumDiff == 0:
|
||
|
|
lastStats(1).NumIgnored++
|
||
|
|
case rv.NumDiff == 0:
|
||
|
|
lastStats(1).NumIdentical++
|
||
|
|
case rv.NumDiff > 0 && !rv.ValueY.IsValid():
|
||
|
|
lastStats(2).NumRemoved++
|
||
|
|
case rv.NumDiff > 0 && !rv.ValueX.IsValid():
|
||
|
|
lastStats(2).NumInserted++
|
||
|
|
default:
|
||
|
|
lastStats(2).NumModified++
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return groups
|
||
|
|
}
|