diff options
Diffstat (limited to 'vendor/github.com/google/go-cmp/cmp/internal/value/format.go')
-rw-r--r-- | vendor/github.com/google/go-cmp/cmp/internal/value/format.go | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/vendor/github.com/google/go-cmp/cmp/internal/value/format.go b/vendor/github.com/google/go-cmp/cmp/internal/value/format.go new file mode 100644 index 00000000..657e5087 --- /dev/null +++ b/vendor/github.com/google/go-cmp/cmp/internal/value/format.go @@ -0,0 +1,277 @@ +// 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.md file. + +// Package value provides functionality for reflect.Value types. +package value + +import ( + "fmt" + "reflect" + "strconv" + "strings" + "unicode" +) + +var stringerIface = reflect.TypeOf((*fmt.Stringer)(nil)).Elem() + +// Format formats the value v as a string. +// +// This is similar to fmt.Sprintf("%+v", v) except this: +// * Prints the type unless it can be elided +// * Avoids printing struct fields that are zero +// * Prints a nil-slice as being nil, not empty +// * Prints map entries in deterministic order +func Format(v reflect.Value, conf FormatConfig) string { + conf.printType = true + conf.followPointers = true + conf.realPointers = true + return formatAny(v, conf, nil) +} + +type FormatConfig struct { + UseStringer bool // Should the String method be used if available? + printType bool // Should we print the type before the value? + PrintPrimitiveType bool // Should we print the type of primitives? + followPointers bool // Should we recursively follow pointers? + realPointers bool // Should we print the real address of pointers? +} + +func formatAny(v reflect.Value, conf FormatConfig, visited map[uintptr]bool) string { + // TODO: Should this be a multi-line printout in certain situations? + + if !v.IsValid() { + return "<non-existent>" + } + if conf.UseStringer && v.Type().Implements(stringerIface) && v.CanInterface() { + if (v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface) && v.IsNil() { + return "<nil>" + } + + const stringerPrefix = "s" // Indicates that the String method was used + s := v.Interface().(fmt.Stringer).String() + return stringerPrefix + formatString(s) + } + + switch v.Kind() { + case reflect.Bool: + return formatPrimitive(v.Type(), v.Bool(), conf) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return formatPrimitive(v.Type(), v.Int(), conf) + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + if v.Type().PkgPath() == "" || v.Kind() == reflect.Uintptr { + // Unnamed uints are usually bytes or words, so use hexadecimal. + return formatPrimitive(v.Type(), formatHex(v.Uint()), conf) + } + return formatPrimitive(v.Type(), v.Uint(), conf) + case reflect.Float32, reflect.Float64: + return formatPrimitive(v.Type(), v.Float(), conf) + case reflect.Complex64, reflect.Complex128: + return formatPrimitive(v.Type(), v.Complex(), conf) + case reflect.String: + return formatPrimitive(v.Type(), formatString(v.String()), conf) + case reflect.UnsafePointer, reflect.Chan, reflect.Func: + return formatPointer(v, conf) + case reflect.Ptr: + if v.IsNil() { + if conf.printType { + return fmt.Sprintf("(%v)(nil)", v.Type()) + } + return "<nil>" + } + if visited[v.Pointer()] || !conf.followPointers { + return formatPointer(v, conf) + } + visited = insertPointer(visited, v.Pointer()) + return "&" + formatAny(v.Elem(), conf, visited) + case reflect.Interface: + if v.IsNil() { + if conf.printType { + return fmt.Sprintf("%v(nil)", v.Type()) + } + return "<nil>" + } + return formatAny(v.Elem(), conf, visited) + case reflect.Slice: + if v.IsNil() { + if conf.printType { + return fmt.Sprintf("%v(nil)", v.Type()) + } + return "<nil>" + } + if visited[v.Pointer()] { + return formatPointer(v, conf) + } + visited = insertPointer(visited, v.Pointer()) + fallthrough + case reflect.Array: + var ss []string + subConf := conf + subConf.printType = v.Type().Elem().Kind() == reflect.Interface + for i := 0; i < v.Len(); i++ { + s := formatAny(v.Index(i), subConf, visited) + ss = append(ss, s) + } + s := fmt.Sprintf("{%s}", strings.Join(ss, ", ")) + if conf.printType { + return v.Type().String() + s + } + return s + case reflect.Map: + if v.IsNil() { + if conf.printType { + return fmt.Sprintf("%v(nil)", v.Type()) + } + return "<nil>" + } + if visited[v.Pointer()] { + return formatPointer(v, conf) + } + visited = insertPointer(visited, v.Pointer()) + + var ss []string + keyConf, valConf := conf, conf + keyConf.printType = v.Type().Key().Kind() == reflect.Interface + keyConf.followPointers = false + valConf.printType = v.Type().Elem().Kind() == reflect.Interface + for _, k := range SortKeys(v.MapKeys()) { + sk := formatAny(k, keyConf, visited) + sv := formatAny(v.MapIndex(k), valConf, visited) + ss = append(ss, fmt.Sprintf("%s: %s", sk, sv)) + } + s := fmt.Sprintf("{%s}", strings.Join(ss, ", ")) + if conf.printType { + return v.Type().String() + s + } + return s + case reflect.Struct: + var ss []string + subConf := conf + subConf.printType = true + for i := 0; i < v.NumField(); i++ { + vv := v.Field(i) + if isZero(vv) { + continue // Elide zero value fields + } + name := v.Type().Field(i).Name + subConf.UseStringer = conf.UseStringer + s := formatAny(vv, subConf, visited) + ss = append(ss, fmt.Sprintf("%s: %s", name, s)) + } + s := fmt.Sprintf("{%s}", strings.Join(ss, ", ")) + if conf.printType { + return v.Type().String() + s + } + return s + default: + panic(fmt.Sprintf("%v kind not handled", v.Kind())) + } +} + +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) + } + if strings.IndexFunc(s, rawInvalid) < 0 { + return "`" + s + "`" + } + return qs +} + +func formatPrimitive(t reflect.Type, v interface{}, conf FormatConfig) string { + if conf.printType && (conf.PrintPrimitiveType || t.PkgPath() != "") { + return fmt.Sprintf("%v(%v)", t, v) + } + return fmt.Sprintf("%v", v) +} + +func formatPointer(v reflect.Value, conf FormatConfig) string { + p := v.Pointer() + if !conf.realPointers { + p = 0 // For deterministic printing purposes + } + s := formatHex(uint64(p)) + if conf.printType { + return fmt.Sprintf("(%v)(%s)", v.Type(), s) + } + return s +} + +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) +} + +// insertPointer insert p into m, allocating m if necessary. +func insertPointer(m map[uintptr]bool, p uintptr) map[uintptr]bool { + if m == nil { + m = make(map[uintptr]bool) + } + m[p] = true + return m +} + +// isZero reports whether v is the zero value. +// This does not rely on Interface and so can be used on unexported fields. +func isZero(v reflect.Value) bool { + switch v.Kind() { + case reflect.Bool: + return v.Bool() == false + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return v.Int() == 0 + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + return v.Uint() == 0 + case reflect.Float32, reflect.Float64: + return v.Float() == 0 + case reflect.Complex64, reflect.Complex128: + return v.Complex() == 0 + case reflect.String: + return v.String() == "" + case reflect.UnsafePointer: + return v.Pointer() == 0 + case reflect.Chan, reflect.Func, reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice: + return v.IsNil() + case reflect.Array: + for i := 0; i < v.Len(); i++ { + if !isZero(v.Index(i)) { + return false + } + } + return true + case reflect.Struct: + for i := 0; i < v.NumField(); i++ { + if !isZero(v.Field(i)) { + return false + } + } + return true + } + return false +} |