forked from toolshed/abra
433 lines
12 KiB
Go
433 lines
12 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 file.
|
||
|
||
package cmp
|
||
|
||
import (
|
||
"bytes"
|
||
"fmt"
|
||
"math/rand"
|
||
"strings"
|
||
"time"
|
||
"unicode/utf8"
|
||
|
||
"github.com/google/go-cmp/cmp/internal/flags"
|
||
)
|
||
|
||
var randBool = rand.New(rand.NewSource(time.Now().Unix())).Intn(2) == 0
|
||
|
||
const maxColumnLength = 80
|
||
|
||
type indentMode int
|
||
|
||
func (n indentMode) appendIndent(b []byte, d diffMode) []byte {
|
||
// The output of Diff is documented as being unstable to provide future
|
||
// flexibility in changing the output for more humanly readable reports.
|
||
// This logic intentionally introduces instability to the exact output
|
||
// so that users can detect accidental reliance on stability early on,
|
||
// rather than much later when an actual change to the format occurs.
|
||
if flags.Deterministic || randBool {
|
||
// Use regular spaces (U+0020).
|
||
switch d {
|
||
case diffUnknown, diffIdentical:
|
||
b = append(b, " "...)
|
||
case diffRemoved:
|
||
b = append(b, "- "...)
|
||
case diffInserted:
|
||
b = append(b, "+ "...)
|
||
}
|
||
} else {
|
||
// Use non-breaking spaces (U+00a0).
|
||
switch d {
|
||
case diffUnknown, diffIdentical:
|
||
b = append(b, " "...)
|
||
case diffRemoved:
|
||
b = append(b, "- "...)
|
||
case diffInserted:
|
||
b = append(b, "+ "...)
|
||
}
|
||
}
|
||
return repeatCount(n).appendChar(b, '\t')
|
||
}
|
||
|
||
type repeatCount int
|
||
|
||
func (n repeatCount) appendChar(b []byte, c byte) []byte {
|
||
for ; n > 0; n-- {
|
||
b = append(b, c)
|
||
}
|
||
return b
|
||
}
|
||
|
||
// textNode is a simplified tree-based representation of structured text.
|
||
// Possible node types are textWrap, textList, or textLine.
|
||
type textNode interface {
|
||
// Len reports the length in bytes of a single-line version of the tree.
|
||
// Nested textRecord.Diff and textRecord.Comment fields are ignored.
|
||
Len() int
|
||
// Equal reports whether the two trees are structurally identical.
|
||
// Nested textRecord.Diff and textRecord.Comment fields are compared.
|
||
Equal(textNode) bool
|
||
// String returns the string representation of the text tree.
|
||
// It is not guaranteed that len(x.String()) == x.Len(),
|
||
// nor that x.String() == y.String() implies that x.Equal(y).
|
||
String() string
|
||
|
||
// formatCompactTo formats the contents of the tree as a single-line string
|
||
// to the provided buffer. Any nested textRecord.Diff and textRecord.Comment
|
||
// fields are ignored.
|
||
//
|
||
// However, not all nodes in the tree should be collapsed as a single-line.
|
||
// If a node can be collapsed as a single-line, it is replaced by a textLine
|
||
// node. Since the top-level node cannot replace itself, this also returns
|
||
// the current node itself.
|
||
//
|
||
// This does not mutate the receiver.
|
||
formatCompactTo([]byte, diffMode) ([]byte, textNode)
|
||
// formatExpandedTo formats the contents of the tree as a multi-line string
|
||
// to the provided buffer. In order for column alignment to operate well,
|
||
// formatCompactTo must be called before calling formatExpandedTo.
|
||
formatExpandedTo([]byte, diffMode, indentMode) []byte
|
||
}
|
||
|
||
// textWrap is a wrapper that concatenates a prefix and/or a suffix
|
||
// to the underlying node.
|
||
type textWrap struct {
|
||
Prefix string // e.g., "bytes.Buffer{"
|
||
Value textNode // textWrap | textList | textLine
|
||
Suffix string // e.g., "}"
|
||
Metadata interface{} // arbitrary metadata; has no effect on formatting
|
||
}
|
||
|
||
func (s *textWrap) Len() int {
|
||
return len(s.Prefix) + s.Value.Len() + len(s.Suffix)
|
||
}
|
||
func (s1 *textWrap) Equal(s2 textNode) bool {
|
||
if s2, ok := s2.(*textWrap); ok {
|
||
return s1.Prefix == s2.Prefix && s1.Value.Equal(s2.Value) && s1.Suffix == s2.Suffix
|
||
}
|
||
return false
|
||
}
|
||
func (s *textWrap) String() string {
|
||
var d diffMode
|
||
var n indentMode
|
||
_, s2 := s.formatCompactTo(nil, d)
|
||
b := n.appendIndent(nil, d) // Leading indent
|
||
b = s2.formatExpandedTo(b, d, n) // Main body
|
||
b = append(b, '\n') // Trailing newline
|
||
return string(b)
|
||
}
|
||
func (s *textWrap) formatCompactTo(b []byte, d diffMode) ([]byte, textNode) {
|
||
n0 := len(b) // Original buffer length
|
||
b = append(b, s.Prefix...)
|
||
b, s.Value = s.Value.formatCompactTo(b, d)
|
||
b = append(b, s.Suffix...)
|
||
if _, ok := s.Value.(textLine); ok {
|
||
return b, textLine(b[n0:])
|
||
}
|
||
return b, s
|
||
}
|
||
func (s *textWrap) formatExpandedTo(b []byte, d diffMode, n indentMode) []byte {
|
||
b = append(b, s.Prefix...)
|
||
b = s.Value.formatExpandedTo(b, d, n)
|
||
b = append(b, s.Suffix...)
|
||
return b
|
||
}
|
||
|
||
// textList is a comma-separated list of textWrap or textLine nodes.
|
||
// The list may be formatted as multi-lines or single-line at the discretion
|
||
// of the textList.formatCompactTo method.
|
||
type textList []textRecord
|
||
type textRecord struct {
|
||
Diff diffMode // e.g., 0 or '-' or '+'
|
||
Key string // e.g., "MyField"
|
||
Value textNode // textWrap | textLine
|
||
ElideComma bool // avoid trailing comma
|
||
Comment fmt.Stringer // e.g., "6 identical fields"
|
||
}
|
||
|
||
// AppendEllipsis appends a new ellipsis node to the list if none already
|
||
// exists at the end. If cs is non-zero it coalesces the statistics with the
|
||
// previous diffStats.
|
||
func (s *textList) AppendEllipsis(ds diffStats) {
|
||
hasStats := !ds.IsZero()
|
||
if len(*s) == 0 || !(*s)[len(*s)-1].Value.Equal(textEllipsis) {
|
||
if hasStats {
|
||
*s = append(*s, textRecord{Value: textEllipsis, ElideComma: true, Comment: ds})
|
||
} else {
|
||
*s = append(*s, textRecord{Value: textEllipsis, ElideComma: true})
|
||
}
|
||
return
|
||
}
|
||
if hasStats {
|
||
(*s)[len(*s)-1].Comment = (*s)[len(*s)-1].Comment.(diffStats).Append(ds)
|
||
}
|
||
}
|
||
|
||
func (s textList) Len() (n int) {
|
||
for i, r := range s {
|
||
n += len(r.Key)
|
||
if r.Key != "" {
|
||
n += len(": ")
|
||
}
|
||
n += r.Value.Len()
|
||
if i < len(s)-1 {
|
||
n += len(", ")
|
||
}
|
||
}
|
||
return n
|
||
}
|
||
|
||
func (s1 textList) Equal(s2 textNode) bool {
|
||
if s2, ok := s2.(textList); ok {
|
||
if len(s1) != len(s2) {
|
||
return false
|
||
}
|
||
for i := range s1 {
|
||
r1, r2 := s1[i], s2[i]
|
||
if !(r1.Diff == r2.Diff && r1.Key == r2.Key && r1.Value.Equal(r2.Value) && r1.Comment == r2.Comment) {
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
}
|
||
return false
|
||
}
|
||
|
||
func (s textList) String() string {
|
||
return (&textWrap{Prefix: "{", Value: s, Suffix: "}"}).String()
|
||
}
|
||
|
||
func (s textList) formatCompactTo(b []byte, d diffMode) ([]byte, textNode) {
|
||
s = append(textList(nil), s...) // Avoid mutating original
|
||
|
||
// Determine whether we can collapse this list as a single line.
|
||
n0 := len(b) // Original buffer length
|
||
var multiLine bool
|
||
for i, r := range s {
|
||
if r.Diff == diffInserted || r.Diff == diffRemoved {
|
||
multiLine = true
|
||
}
|
||
b = append(b, r.Key...)
|
||
if r.Key != "" {
|
||
b = append(b, ": "...)
|
||
}
|
||
b, s[i].Value = r.Value.formatCompactTo(b, d|r.Diff)
|
||
if _, ok := s[i].Value.(textLine); !ok {
|
||
multiLine = true
|
||
}
|
||
if r.Comment != nil {
|
||
multiLine = true
|
||
}
|
||
if i < len(s)-1 {
|
||
b = append(b, ", "...)
|
||
}
|
||
}
|
||
// Force multi-lined output when printing a removed/inserted node that
|
||
// is sufficiently long.
|
||
if (d == diffInserted || d == diffRemoved) && len(b[n0:]) > maxColumnLength {
|
||
multiLine = true
|
||
}
|
||
if !multiLine {
|
||
return b, textLine(b[n0:])
|
||
}
|
||
return b, s
|
||
}
|
||
|
||
func (s textList) formatExpandedTo(b []byte, d diffMode, n indentMode) []byte {
|
||
alignKeyLens := s.alignLens(
|
||
func(r textRecord) bool {
|
||
_, isLine := r.Value.(textLine)
|
||
return r.Key == "" || !isLine
|
||
},
|
||
func(r textRecord) int { return utf8.RuneCountInString(r.Key) },
|
||
)
|
||
alignValueLens := s.alignLens(
|
||
func(r textRecord) bool {
|
||
_, isLine := r.Value.(textLine)
|
||
return !isLine || r.Value.Equal(textEllipsis) || r.Comment == nil
|
||
},
|
||
func(r textRecord) int { return utf8.RuneCount(r.Value.(textLine)) },
|
||
)
|
||
|
||
// Format lists of simple lists in a batched form.
|
||
// If the list is sequence of only textLine values,
|
||
// then batch multiple values on a single line.
|
||
var isSimple bool
|
||
for _, r := range s {
|
||
_, isLine := r.Value.(textLine)
|
||
isSimple = r.Diff == 0 && r.Key == "" && isLine && r.Comment == nil
|
||
if !isSimple {
|
||
break
|
||
}
|
||
}
|
||
if isSimple {
|
||
n++
|
||
var batch []byte
|
||
emitBatch := func() {
|
||
if len(batch) > 0 {
|
||
b = n.appendIndent(append(b, '\n'), d)
|
||
b = append(b, bytes.TrimRight(batch, " ")...)
|
||
batch = batch[:0]
|
||
}
|
||
}
|
||
for _, r := range s {
|
||
line := r.Value.(textLine)
|
||
if len(batch)+len(line)+len(", ") > maxColumnLength {
|
||
emitBatch()
|
||
}
|
||
batch = append(batch, line...)
|
||
batch = append(batch, ", "...)
|
||
}
|
||
emitBatch()
|
||
n--
|
||
return n.appendIndent(append(b, '\n'), d)
|
||
}
|
||
|
||
// Format the list as a multi-lined output.
|
||
n++
|
||
for i, r := range s {
|
||
b = n.appendIndent(append(b, '\n'), d|r.Diff)
|
||
if r.Key != "" {
|
||
b = append(b, r.Key+": "...)
|
||
}
|
||
b = alignKeyLens[i].appendChar(b, ' ')
|
||
|
||
b = r.Value.formatExpandedTo(b, d|r.Diff, n)
|
||
if !r.ElideComma {
|
||
b = append(b, ',')
|
||
}
|
||
b = alignValueLens[i].appendChar(b, ' ')
|
||
|
||
if r.Comment != nil {
|
||
b = append(b, " // "+r.Comment.String()...)
|
||
}
|
||
}
|
||
n--
|
||
|
||
return n.appendIndent(append(b, '\n'), d)
|
||
}
|
||
|
||
func (s textList) alignLens(
|
||
skipFunc func(textRecord) bool,
|
||
lenFunc func(textRecord) int,
|
||
) []repeatCount {
|
||
var startIdx, endIdx, maxLen int
|
||
lens := make([]repeatCount, len(s))
|
||
for i, r := range s {
|
||
if skipFunc(r) {
|
||
for j := startIdx; j < endIdx && j < len(s); j++ {
|
||
lens[j] = repeatCount(maxLen - lenFunc(s[j]))
|
||
}
|
||
startIdx, endIdx, maxLen = i+1, i+1, 0
|
||
} else {
|
||
if maxLen < lenFunc(r) {
|
||
maxLen = lenFunc(r)
|
||
}
|
||
endIdx = i + 1
|
||
}
|
||
}
|
||
for j := startIdx; j < endIdx && j < len(s); j++ {
|
||
lens[j] = repeatCount(maxLen - lenFunc(s[j]))
|
||
}
|
||
return lens
|
||
}
|
||
|
||
// textLine is a single-line segment of text and is always a leaf node
|
||
// in the textNode tree.
|
||
type textLine []byte
|
||
|
||
var (
|
||
textNil = textLine("nil")
|
||
textEllipsis = textLine("...")
|
||
)
|
||
|
||
func (s textLine) Len() int {
|
||
return len(s)
|
||
}
|
||
func (s1 textLine) Equal(s2 textNode) bool {
|
||
if s2, ok := s2.(textLine); ok {
|
||
return bytes.Equal([]byte(s1), []byte(s2))
|
||
}
|
||
return false
|
||
}
|
||
func (s textLine) String() string {
|
||
return string(s)
|
||
}
|
||
func (s textLine) formatCompactTo(b []byte, d diffMode) ([]byte, textNode) {
|
||
return append(b, s...), s
|
||
}
|
||
func (s textLine) formatExpandedTo(b []byte, _ diffMode, _ indentMode) []byte {
|
||
return append(b, s...)
|
||
}
|
||
|
||
type diffStats struct {
|
||
Name string
|
||
NumIgnored int
|
||
NumIdentical int
|
||
NumRemoved int
|
||
NumInserted int
|
||
NumModified int
|
||
}
|
||
|
||
func (s diffStats) IsZero() bool {
|
||
s.Name = ""
|
||
return s == diffStats{}
|
||
}
|
||
|
||
func (s diffStats) NumDiff() int {
|
||
return s.NumRemoved + s.NumInserted + s.NumModified
|
||
}
|
||
|
||
func (s diffStats) Append(ds diffStats) diffStats {
|
||
assert(s.Name == ds.Name)
|
||
s.NumIgnored += ds.NumIgnored
|
||
s.NumIdentical += ds.NumIdentical
|
||
s.NumRemoved += ds.NumRemoved
|
||
s.NumInserted += ds.NumInserted
|
||
s.NumModified += ds.NumModified
|
||
return s
|
||
}
|
||
|
||
// String prints a humanly-readable summary of coalesced records.
|
||
//
|
||
// Example:
|
||
//
|
||
// diffStats{Name: "Field", NumIgnored: 5}.String() => "5 ignored fields"
|
||
func (s diffStats) String() string {
|
||
var ss []string
|
||
var sum int
|
||
labels := [...]string{"ignored", "identical", "removed", "inserted", "modified"}
|
||
counts := [...]int{s.NumIgnored, s.NumIdentical, s.NumRemoved, s.NumInserted, s.NumModified}
|
||
for i, n := range counts {
|
||
if n > 0 {
|
||
ss = append(ss, fmt.Sprintf("%d %v", n, labels[i]))
|
||
}
|
||
sum += n
|
||
}
|
||
|
||
// Pluralize the name (adjusting for some obscure English grammar rules).
|
||
name := s.Name
|
||
if sum > 1 {
|
||
name += "s"
|
||
if strings.HasSuffix(name, "ys") {
|
||
name = name[:len(name)-2] + "ies" // e.g., "entrys" => "entries"
|
||
}
|
||
}
|
||
|
||
// Format the list according to English grammar (with Oxford comma).
|
||
switch n := len(ss); n {
|
||
case 0:
|
||
return ""
|
||
case 1, 2:
|
||
return strings.Join(ss, " and ") + " " + name
|
||
default:
|
||
return strings.Join(ss[:n-1], ", ") + ", and " + ss[n-1] + " " + name
|
||
}
|
||
}
|
||
|
||
type commentString string
|
||
|
||
func (s commentString) String() string { return string(s) }
|