--- /dev/null
+// 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 (
+ "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) }
projects / dotfiles / .git / blobdiff