--- /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 file.
+
+package cmp
+
+import (
+ "bytes"
+ "fmt"
+ "reflect"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf8"
+
+ "github.com/google/go-cmp/cmp/internal/value"
+)
+
+type formatValueOptions struct {
+ // AvoidStringer controls whether to avoid calling custom stringer
+ // methods like error.Error or fmt.Stringer.String.
+ AvoidStringer bool
+
+ // PrintAddresses controls whether to print the address of all pointers,
+ // slice elements, and maps.
+ PrintAddresses bool
+
+ // QualifiedNames controls whether FormatType uses the fully qualified name
+ // (including the full package path as opposed to just the package name).
+ QualifiedNames bool
+
+ // VerbosityLevel controls the amount of output to produce.
+ // A higher value produces more output. A value of zero or lower produces
+ // no output (represented using an ellipsis).
+ // If LimitVerbosity is false, then the level is treated as infinite.
+ VerbosityLevel int
+
+ // LimitVerbosity specifies that formatting should respect VerbosityLevel.
+ LimitVerbosity bool
+}
+
+// FormatType prints the type as if it were wrapping s.
+// This may return s as-is depending on the current type and TypeMode mode.
+func (opts formatOptions) FormatType(t reflect.Type, s textNode) textNode {
+ // Check whether to emit the type or not.
+ switch opts.TypeMode {
+ case autoType:
+ switch t.Kind() {
+ case reflect.Struct, reflect.Slice, reflect.Array, reflect.Map:
+ if s.Equal(textNil) {
+ return s
+ }
+ default:
+ return s
+ }
+ if opts.DiffMode == diffIdentical {
+ return s // elide type for identical nodes
+ }
+ case elideType:
+ return s
+ }
+
+ // Determine the type label, applying special handling for unnamed types.
+ typeName := value.TypeString(t, opts.QualifiedNames)
+ if t.Name() == "" {
+ // According to Go grammar, certain type literals contain symbols that
+ // do not strongly bind to the next lexicographical token (e.g., *T).
+ switch t.Kind() {
+ case reflect.Chan, reflect.Func, reflect.Ptr:
+ typeName = "(" + typeName + ")"
+ }
+ }
+ return &textWrap{Prefix: typeName, Value: wrapParens(s)}
+}
+
+// wrapParens wraps s with a set of parenthesis, but avoids it if the
+// wrapped node itself is already surrounded by a pair of parenthesis or braces.
+// It handles unwrapping one level of pointer-reference nodes.
+func wrapParens(s textNode) textNode {
+ var refNode *textWrap
+ if s2, ok := s.(*textWrap); ok {
+ // Unwrap a single pointer reference node.
+ switch s2.Metadata.(type) {
+ case leafReference, trunkReference, trunkReferences:
+ refNode = s2
+ if s3, ok := refNode.Value.(*textWrap); ok {
+ s2 = s3
+ }
+ }
+
+ // Already has delimiters that make parenthesis unnecessary.
+ hasParens := strings.HasPrefix(s2.Prefix, "(") && strings.HasSuffix(s2.Suffix, ")")
+ hasBraces := strings.HasPrefix(s2.Prefix, "{") && strings.HasSuffix(s2.Suffix, "}")
+ if hasParens || hasBraces {
+ return s
+ }
+ }
+ if refNode != nil {
+ refNode.Value = &textWrap{Prefix: "(", Value: refNode.Value, Suffix: ")"}
+ return s
+ }
+ return &textWrap{Prefix: "(", Value: s, Suffix: ")"}
+}
+
+// FormatValue prints the reflect.Value, taking extra care to avoid descending
+// into pointers already in ptrs. As pointers are visited, ptrs is also updated.
+func (opts formatOptions) FormatValue(v reflect.Value, parentKind reflect.Kind, ptrs *pointerReferences) (out textNode) {
+ if !v.IsValid() {
+ return nil
+ }
+ t := v.Type()
+
+ // Check slice element for cycles.
+ if parentKind == reflect.Slice {
+ ptrRef, visited := ptrs.Push(v.Addr())
+ if visited {
+ return makeLeafReference(ptrRef, false)
+ }
+ defer ptrs.Pop()
+ defer func() { out = wrapTrunkReference(ptrRef, false, out) }()
+ }
+
+ // Check whether there is an Error or String method to call.
+ if !opts.AvoidStringer && v.CanInterface() {
+ // Avoid calling Error or String methods on nil receivers since many
+ // implementations crash when doing so.
+ if (t.Kind() != reflect.Ptr && t.Kind() != reflect.Interface) || !v.IsNil() {
+ var prefix, strVal string
+ func() {
+ // Swallow and ignore any panics from String or Error.
+ defer func() { recover() }()
+ switch v := v.Interface().(type) {
+ case error:
+ strVal = v.Error()
+ prefix = "e"
+ case fmt.Stringer:
+ strVal = v.String()
+ prefix = "s"
+ }
+ }()
+ if prefix != "" {
+ return opts.formatString(prefix, strVal)
+ }
+ }
+ }
+
+ // Check whether to explicitly wrap the result with the type.
+ var skipType bool
+ defer func() {
+ if !skipType {
+ out = opts.FormatType(t, out)
+ }
+ }()
+
+ switch t.Kind() {
+ case reflect.Bool:
+ return textLine(fmt.Sprint(v.Bool()))
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ return textLine(fmt.Sprint(v.Int()))
+ case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+ return textLine(fmt.Sprint(v.Uint()))
+ case reflect.Uint8:
+ if parentKind == reflect.Slice || parentKind == reflect.Array {
+ return textLine(formatHex(v.Uint()))
+ }
+ return textLine(fmt.Sprint(v.Uint()))
+ case reflect.Uintptr:
+ return textLine(formatHex(v.Uint()))
+ case reflect.Float32, reflect.Float64:
+ return textLine(fmt.Sprint(v.Float()))
+ case reflect.Complex64, reflect.Complex128:
+ return textLine(fmt.Sprint(v.Complex()))
+ case reflect.String:
+ return opts.formatString("", v.String())
+ case reflect.UnsafePointer, reflect.Chan, reflect.Func:
+ return textLine(formatPointer(value.PointerOf(v), true))
+ case reflect.Struct:
+ var list textList
+ v := makeAddressable(v) // needed for retrieveUnexportedField
+ maxLen := v.NumField()
+ if opts.LimitVerbosity {
+ maxLen = ((1 << opts.verbosity()) >> 1) << 2 // 0, 4, 8, 16, 32, etc...
+ opts.VerbosityLevel--
+ }
+ for i := 0; i < v.NumField(); i++ {
+ vv := v.Field(i)
+ if value.IsZero(vv) {
+ continue // Elide fields with zero values
+ }
+ if len(list) == maxLen {
+ list.AppendEllipsis(diffStats{})
+ break
+ }
+ sf := t.Field(i)
+ if supportExporters && !isExported(sf.Name) {
+ vv = retrieveUnexportedField(v, sf, true)
+ }
+ s := opts.WithTypeMode(autoType).FormatValue(vv, t.Kind(), ptrs)
+ list = append(list, textRecord{Key: sf.Name, Value: s})
+ }
+ return &textWrap{Prefix: "{", Value: list, Suffix: "}"}
+ case reflect.Slice:
+ if v.IsNil() {
+ return textNil
+ }
+
+ // Check whether this is a []byte of text data.
+ if t.Elem() == reflect.TypeOf(byte(0)) {
+ b := v.Bytes()
+ isPrintSpace := func(r rune) bool { return unicode.IsPrint(r) && unicode.IsSpace(r) }
+ if len(b) > 0 && utf8.Valid(b) && len(bytes.TrimFunc(b, isPrintSpace)) == 0 {
+ out = opts.formatString("", string(b))
+ return opts.WithTypeMode(emitType).FormatType(t, out)
+ }
+ }
+
+ fallthrough
+ case reflect.Array:
+ maxLen := v.Len()
+ if opts.LimitVerbosity {
+ maxLen = ((1 << opts.verbosity()) >> 1) << 2 // 0, 4, 8, 16, 32, etc...
+ opts.VerbosityLevel--
+ }
+ var list textList
+ for i := 0; i < v.Len(); i++ {
+ if len(list) == maxLen {
+ list.AppendEllipsis(diffStats{})
+ break
+ }
+ s := opts.WithTypeMode(elideType).FormatValue(v.Index(i), t.Kind(), ptrs)
+ list = append(list, textRecord{Value: s})
+ }
+
+ out = &textWrap{Prefix: "{", Value: list, Suffix: "}"}
+ if t.Kind() == reflect.Slice && opts.PrintAddresses {
+ header := fmt.Sprintf("ptr:%v, len:%d, cap:%d", formatPointer(value.PointerOf(v), false), v.Len(), v.Cap())
+ out = &textWrap{Prefix: pointerDelimPrefix + header + pointerDelimSuffix, Value: out}
+ }
+ return out
+ case reflect.Map:
+ if v.IsNil() {
+ return textNil
+ }
+
+ // Check pointer for cycles.
+ ptrRef, visited := ptrs.Push(v)
+ if visited {
+ return makeLeafReference(ptrRef, opts.PrintAddresses)
+ }
+ defer ptrs.Pop()
+
+ maxLen := v.Len()
+ if opts.LimitVerbosity {
+ maxLen = ((1 << opts.verbosity()) >> 1) << 2 // 0, 4, 8, 16, 32, etc...
+ opts.VerbosityLevel--
+ }
+ var list textList
+ for _, k := range value.SortKeys(v.MapKeys()) {
+ if len(list) == maxLen {
+ list.AppendEllipsis(diffStats{})
+ break
+ }
+ sk := formatMapKey(k, false, ptrs)
+ sv := opts.WithTypeMode(elideType).FormatValue(v.MapIndex(k), t.Kind(), ptrs)
+ list = append(list, textRecord{Key: sk, Value: sv})
+ }
+
+ out = &textWrap{Prefix: "{", Value: list, Suffix: "}"}
+ out = wrapTrunkReference(ptrRef, opts.PrintAddresses, out)
+ return out
+ case reflect.Ptr:
+ if v.IsNil() {
+ return textNil
+ }
+
+ // Check pointer for cycles.
+ ptrRef, visited := ptrs.Push(v)
+ if visited {
+ out = makeLeafReference(ptrRef, opts.PrintAddresses)
+ return &textWrap{Prefix: "&", Value: out}
+ }
+ defer ptrs.Pop()
+
+ skipType = true // Let the underlying value print the type instead
+ out = opts.FormatValue(v.Elem(), t.Kind(), ptrs)
+ out = wrapTrunkReference(ptrRef, opts.PrintAddresses, out)
+ out = &textWrap{Prefix: "&", Value: out}
+ return out
+ case reflect.Interface:
+ if v.IsNil() {
+ return textNil
+ }
+ // Interfaces accept different concrete types,
+ // so configure the underlying value to explicitly print the type.
+ skipType = true // Print the concrete type instead
+ return opts.WithTypeMode(emitType).FormatValue(v.Elem(), t.Kind(), ptrs)
+ default:
+ panic(fmt.Sprintf("%v kind not handled", v.Kind()))
+ }
+}
+
+func (opts formatOptions) formatString(prefix, s string) textNode {
+ maxLen := len(s)
+ maxLines := strings.Count(s, "\n") + 1
+ if opts.LimitVerbosity {
+ maxLen = (1 << opts.verbosity()) << 5 // 32, 64, 128, 256, etc...
+ maxLines = (1 << opts.verbosity()) << 2 // 4, 8, 16, 32, 64, etc...
+ }
+
+ // For multiline strings, use the triple-quote syntax,
+ // but only use it when printing removed or inserted nodes since
+ // we only want the extra verbosity for those cases.
+ lines := strings.Split(strings.TrimSuffix(s, "\n"), "\n")
+ isTripleQuoted := len(lines) >= 4 && (opts.DiffMode == '-' || opts.DiffMode == '+')
+ for i := 0; i < len(lines) && isTripleQuoted; i++ {
+ lines[i] = strings.TrimPrefix(strings.TrimSuffix(lines[i], "\r"), "\r") // trim leading/trailing carriage returns for legacy Windows endline support
+ isPrintable := func(r rune) bool {
+ return unicode.IsPrint(r) || r == '\t' // specially treat tab as printable
+ }
+ line := lines[i]
+ isTripleQuoted = !strings.HasPrefix(strings.TrimPrefix(line, prefix), `"""`) && !strings.HasPrefix(line, "...") && strings.TrimFunc(line, isPrintable) == "" && len(line) <= maxLen
+ }
+ if isTripleQuoted {
+ var list textList
+ list = append(list, textRecord{Diff: opts.DiffMode, Value: textLine(prefix + `"""`), ElideComma: true})
+ for i, line := range lines {
+ if numElided := len(lines) - i; i == maxLines-1 && numElided > 1 {
+ comment := commentString(fmt.Sprintf("%d elided lines", numElided))
+ list = append(list, textRecord{Diff: opts.DiffMode, Value: textEllipsis, ElideComma: true, Comment: comment})
+ break
+ }
+ list = append(list, textRecord{Diff: opts.DiffMode, Value: textLine(line), ElideComma: true})
+ }
+ list = append(list, textRecord{Diff: opts.DiffMode, Value: textLine(prefix + `"""`), ElideComma: true})
+ return &textWrap{Prefix: "(", Value: list, Suffix: ")"}
+ }
+
+ // Format the string as a single-line quoted string.
+ if len(s) > maxLen+len(textEllipsis) {
+ return textLine(prefix + formatString(s[:maxLen]) + string(textEllipsis))
+ }
+ return textLine(prefix + formatString(s))
+}
+
+// formatMapKey formats v as if it were a map key.
+// The result is guaranteed to be a single line.
+func formatMapKey(v reflect.Value, disambiguate bool, ptrs *pointerReferences) string {
+ var opts formatOptions
+ opts.DiffMode = diffIdentical
+ opts.TypeMode = elideType
+ opts.PrintAddresses = disambiguate
+ opts.AvoidStringer = disambiguate
+ opts.QualifiedNames = disambiguate
+ opts.VerbosityLevel = maxVerbosityPreset
+ opts.LimitVerbosity = true
+ s := opts.FormatValue(v, reflect.Map, ptrs).String()
+ return strings.TrimSpace(s)
+}
+
+// formatString prints s as a double-quoted or backtick-quoted string.
+func formatString(s string) string {
+ // Use quoted string if it the same length as a raw string literal.
+ // Otherwise, attempt to use the raw string form.
+ qs := strconv.Quote(s)
+ if len(qs) == 1+len(s)+1 {
+ return qs
+ }
+
+ // Disallow newlines to ensure output is a single line.
+ // Only allow printable runes for readability purposes.
+ rawInvalid := func(r rune) bool {
+ return r == '`' || r == '\n' || !(unicode.IsPrint(r) || r == '\t')
+ }
+ if utf8.ValidString(s) && strings.IndexFunc(s, rawInvalid) < 0 {
+ return "`" + s + "`"
+ }
+ return qs
+}
+
+// formatHex prints u as a hexadecimal integer in Go notation.
+func formatHex(u uint64) string {
+ var f string
+ switch {
+ case u <= 0xff:
+ f = "0x%02x"
+ case u <= 0xffff:
+ f = "0x%04x"
+ case u <= 0xffffff:
+ f = "0x%06x"
+ case u <= 0xffffffff:
+ f = "0x%08x"
+ case u <= 0xffffffffff:
+ f = "0x%010x"
+ case u <= 0xffffffffffff:
+ f = "0x%012x"
+ case u <= 0xffffffffffffff:
+ f = "0x%014x"
+ case u <= 0xffffffffffffffff:
+ f = "0x%016x"
+ }
+ return fmt.Sprintf(f, u)
+}
projects / dotfiles / .git / blobdiff