repo fixes

* Allow strings/json.Number with just zeroes after the decmial point to be converted to integer`
* Allow nil in ToFloat*
* Remove some test duplication
* replace testify with quicktest
* Enable integer and float conversion of time.Weekday values

Fixes #139
Fixes #141

.github/workflows/go.yml

@@ -0,0 +1,28 @@
+name: Go
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    strategy:
+        matrix:
+          go-version: [1.16.x, 1.17.x, 1.18.x]
+          os: [ubuntu-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ matrix.go-version }}
+
+    - name: Build
+      run: go build -v ./...
+
+    - name: Test
+      run: go test -race -v ./...

.travis.yml

@@ -1,16 +0,0 @@
-language: go
-env:
-  -  GO111MODULE=on
-sudo: required
-go:
-  - "1.11.x"
-  - "1.12.x"
-  - tip
-os:
-  - linux
-matrix:
-  allow_failures:
-    - go: tip
-  fast_finish: true
-script:
-  - make check

README.md

@@ -1,8 +1,8 @@
 cast
 ====
-[![GoDoc](https://godoc.org/github.com/spf13/cast?status.svg)](https://godoc.org/github.com/spf13/cast)
-[![Build Status](https://api.travis-ci.org/spf13/cast.svg?branch=master)](https://travis-ci.org/spf13/cast)
-[![Go Report Card](https://goreportcard.com/badge/github.com/spf13/cast)](https://goreportcard.com/report/github.com/spf13/cast)
+[![GoDoc](https://godoc.org/git.internal/re/cast?status.svg)](https://godoc.org/git.internal/re/cast)
+[![Build Status](https://git.internal/re/cast/actions/workflows/go.yml/badge.svg)](https://git.internal/re/cast/actions/workflows/go.yml)
+[![Go Report Card](https://goreportcard.com/badge/git.internal/re/cast)](https://goreportcard.com/report/git.internal/re/cast)
 
 Easy and safe casting from one type to another in Go
 

cast.go

@@ -20,6 +20,11 @@ func ToTime(i interface{}) time.Time {
 	return v
 }
 
+func ToTimeInDefaultLocation(i interface{}, location *time.Location) time.Time {
+	v, _ := ToTimeInDefaultLocationE(i, location)
+	return v
+}
+
 // ToDuration casts an interface to a time.Duration type.
 func ToDuration(i interface{}) time.Duration {
 	v, _ := ToDurationE(i)

caste.go

@@ -20,13 +20,26 @@ var errNegativeNotAllowed = errors.New("unable to cast negative value")
 
 // ToTimeE casts an interface to a time.Time type.
 func ToTimeE(i interface{}) (tim time.Time, err error) {
+	return ToTimeInDefaultLocationE(i, time.UTC)
+}
+
+// ToTimeInDefaultLocationE casts an empty interface to time.Time,
+// interpreting inputs without a timezone to be in the given location,
+// or the local timezone if nil.
+func ToTimeInDefaultLocationE(i interface{}, location *time.Location) (tim time.Time, err error) {
 	i = indirect(i)
 
 	switch v := i.(type) {
 	case time.Time:
 		return v, nil
 	case string:
-		return StringToDate(v)
+		return StringToDateInDefaultLocation(v, location)
+	case json.Number:
+		s, err1 := ToInt64E(v)
+		if err1 != nil {
+			return time.Time{}, fmt.Errorf("unable to cast %#v of type %T to Time", i, i)
+		}
+		return time.Unix(s, 0), nil
 	case int:
 		return time.Unix(int64(v), 0), nil
 	case int64:
@@ -64,6 +77,11 @@ func ToDurationE(i interface{}) (d time.Duration, err error) {
 			d, err = time.ParseDuration(s + "ns")
 		}
 		return
+	case json.Number:
+		var v float64
+		v, err = s.Float64()
+		d = time.Duration(v)
+		return
 	default:
 		err = fmt.Errorf("unable to cast %#v of type %T to Duration", i, i)
 		return
@@ -86,6 +104,12 @@ func ToBoolE(i interface{}) (bool, error) {
 		return false, nil
 	case string:
 		return strconv.ParseBool(i.(string))
+	case json.Number:
+		v, err := ToInt64E(b)
+		if err == nil {
+			return v != 0, nil
+		}
+		return false, fmt.Errorf("unable to cast %#v of type %T to bool", i, i)
 	default:
 		return false, fmt.Errorf("unable to cast %#v of type %T to bool", i, i)
 	}
@@ -95,13 +119,16 @@ func ToBoolE(i interface{}) (bool, error) {
 func ToFloat64E(i interface{}) (float64, error) {
 	i = indirect(i)
 
+	intv, ok := toInt(i)
+	if ok {
+		return float64(intv), nil
+	}
+
 	switch s := i.(type) {
 	case float64:
 		return s, nil
 	case float32:
 		return float64(s), nil
-	case int:
-		return float64(s), nil
 	case int64:
 		return float64(s), nil
 	case int32:
@@ -126,11 +153,19 @@ func ToFloat64E(i interface{}) (float64, error) {
 			return v, nil
 		}
 		return 0, fmt.Errorf("unable to cast %#v of type %T to float64", i, i)
+	case json.Number:
+		v, err := s.Float64()
+		if err == nil {
+			return v, nil
+		}
+		return 0, fmt.Errorf("unable to cast %#v of type %T to float64", i, i)
 	case bool:
 		if s {
 			return 1, nil
 		}
 		return 0, nil
+	case nil:
+		return 0, nil
 	default:
 		return 0, fmt.Errorf("unable to cast %#v of type %T to float64", i, i)
 	}
@@ -140,13 +175,16 @@ func ToFloat64E(i interface{}) (float64, error) {
 func ToFloat32E(i interface{}) (float32, error) {
 	i = indirect(i)
 
+	intv, ok := toInt(i)
+	if ok {
+		return float32(intv), nil
+	}
+
 	switch s := i.(type) {
 	case float64:
 		return float32(s), nil
 	case float32:
 		return s, nil
-	case int:
-		return float32(s), nil
 	case int64:
 		return float32(s), nil
 	case int32:
@@ -171,11 +209,19 @@ func ToFloat32E(i interface{}) (float32, error) {
 			return float32(v), nil
 		}
 		return 0, fmt.Errorf("unable to cast %#v of type %T to float32", i, i)
+	case json.Number:
+		v, err := s.Float64()
+		if err == nil {
+			return float32(v), nil
+		}
+		return 0, fmt.Errorf("unable to cast %#v of type %T to float32", i, i)
 	case bool:
 		if s {
 			return 1, nil
 		}
 		return 0, nil
+	case nil:
+		return 0, nil
 	default:
 		return 0, fmt.Errorf("unable to cast %#v of type %T to float32", i, i)
 	}
@@ -185,9 +231,12 @@ func ToFloat32E(i interface{}) (float32, error) {
 func ToInt64E(i interface{}) (int64, error) {
 	i = indirect(i)
 
+	intv, ok := toInt(i)
+	if ok {
+		return int64(intv), nil
+	}
+
 	switch s := i.(type) {
-	case int:
-		return int64(s), nil
 	case int64:
 		return s, nil
 	case int32:
@@ -211,11 +260,13 @@ func ToInt64E(i interface{}) (int64, error) {
 	case float32:
 		return int64(s), nil
 	case string:
-		v, err := strconv.ParseInt(s, 0, 0)
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
 		if err == nil {
 			return v, nil
 		}
 		return 0, fmt.Errorf("unable to cast %#v of type %T to int64", i, i)
+	case json.Number:
+		return ToInt64E(string(s))
 	case bool:
 		if s {
 			return 1, nil
@@ -232,9 +283,12 @@ func ToInt64E(i interface{}) (int64, error) {
 func ToInt32E(i interface{}) (int32, error) {
 	i = indirect(i)
 
+	intv, ok := toInt(i)
+	if ok {
+		return int32(intv), nil
+	}
+
 	switch s := i.(type) {
-	case int:
-		return int32(s), nil
 	case int64:
 		return int32(s), nil
 	case int32:
@@ -258,11 +312,13 @@ func ToInt32E(i interface{}) (int32, error) {
 	case float32:
 		return int32(s), nil
 	case string:
-		v, err := strconv.ParseInt(s, 0, 0)
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
 		if err == nil {
 			return int32(v), nil
 		}
 		return 0, fmt.Errorf("unable to cast %#v of type %T to int32", i, i)
+	case json.Number:
+		return ToInt32E(string(s))
 	case bool:
 		if s {
 			return 1, nil
@@ -279,9 +335,12 @@ func ToInt32E(i interface{}) (int32, error) {
 func ToInt16E(i interface{}) (int16, error) {
 	i = indirect(i)
 
+	intv, ok := toInt(i)
+	if ok {
+		return int16(intv), nil
+	}
+
 	switch s := i.(type) {
-	case int:
-		return int16(s), nil
 	case int64:
 		return int16(s), nil
 	case int32:
@@ -305,11 +364,13 @@ func ToInt16E(i interface{}) (int16, error) {
 	case float32:
 		return int16(s), nil
 	case string:
-		v, err := strconv.ParseInt(s, 0, 0)
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
 		if err == nil {
 			return int16(v), nil
 		}
 		return 0, fmt.Errorf("unable to cast %#v of type %T to int16", i, i)
+	case json.Number:
+		return ToInt16E(string(s))
 	case bool:
 		if s {
 			return 1, nil
@@ -326,9 +387,12 @@ func ToInt16E(i interface{}) (int16, error) {
 func ToInt8E(i interface{}) (int8, error) {
 	i = indirect(i)
 
+	intv, ok := toInt(i)
+	if ok {
+		return int8(intv), nil
+	}
+
 	switch s := i.(type) {
-	case int:
-		return int8(s), nil
 	case int64:
 		return int8(s), nil
 	case int32:
@@ -352,11 +416,13 @@ func ToInt8E(i interface{}) (int8, error) {
 	case float32:
 		return int8(s), nil
 	case string:
-		v, err := strconv.ParseInt(s, 0, 0)
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
 		if err == nil {
 			return int8(v), nil
 		}
 		return 0, fmt.Errorf("unable to cast %#v of type %T to int8", i, i)
+	case json.Number:
+		return ToInt8E(string(s))
 	case bool:
 		if s {
 			return 1, nil
@@ -373,9 +439,12 @@ func ToInt8E(i interface{}) (int8, error) {
 func ToIntE(i interface{}) (int, error) {
 	i = indirect(i)
 
+	intv, ok := toInt(i)
+	if ok {
+		return intv, nil
+	}
+
 	switch s := i.(type) {
-	case int:
-		return s, nil
 	case int64:
 		return int(s), nil
 	case int32:
@@ -399,11 +468,13 @@ func ToIntE(i interface{}) (int, error) {
 	case float32:
 		return int(s), nil
 	case string:
-		v, err := strconv.ParseInt(s, 0, 0)
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
 		if err == nil {
 			return int(v), nil
 		}
-		return 0, fmt.Errorf("unable to cast %#v of type %T to int", i, i)
+		return 0, fmt.Errorf("unable to cast %#v of type %T to int64", i, i)
+	case json.Number:
+		return ToIntE(string(s))
 	case bool:
 		if s {
 			return 1, nil
@@ -420,18 +491,26 @@ func ToIntE(i interface{}) (int, error) {
 func ToUintE(i interface{}) (uint, error) {
 	i = indirect(i)
 
-	switch s := i.(type) {
-	case string:
-		v, err := strconv.ParseUint(s, 0, 0)
-		if err == nil {
-			return uint(v), nil
-		}
-		return 0, fmt.Errorf("unable to cast %#v to uint: %s", i, err)
-	case int:
-		if s < 0 {
+	intv, ok := toInt(i)
+	if ok {
+		if intv < 0 {
 			return 0, errNegativeNotAllowed
 		}
-		return uint(s), nil
+		return uint(intv), nil
+	}
+
+	switch s := i.(type) {
+	case string:
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
+		if err == nil {
+			if v < 0 {
+				return 0, errNegativeNotAllowed
+			}
+			return uint(v), nil
+		}
+		return 0, fmt.Errorf("unable to cast %#v of type %T to uint", i, i)
+	case json.Number:
+		return ToUintE(string(s))
 	case int64:
 		if s < 0 {
 			return 0, errNegativeNotAllowed
@@ -488,18 +567,26 @@ func ToUintE(i interface{}) (uint, error) {
 func ToUint64E(i interface{}) (uint64, error) {
 	i = indirect(i)
 
-	switch s := i.(type) {
-	case string:
-		v, err := strconv.ParseUint(s, 0, 64)
-		if err == nil {
-			return v, nil
-		}
-		return 0, fmt.Errorf("unable to cast %#v to uint64: %s", i, err)
-	case int:
-		if s < 0 {
+	intv, ok := toInt(i)
+	if ok {
+		if intv < 0 {
 			return 0, errNegativeNotAllowed
 		}
-		return uint64(s), nil
+		return uint64(intv), nil
+	}
+
+	switch s := i.(type) {
+	case string:
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
+		if err == nil {
+			if v < 0 {
+				return 0, errNegativeNotAllowed
+			}
+			return uint64(v), nil
+		}
+		return 0, fmt.Errorf("unable to cast %#v of type %T to uint64", i, i)
+	case json.Number:
+		return ToUint64E(string(s))
 	case int64:
 		if s < 0 {
 			return 0, errNegativeNotAllowed
@@ -556,18 +643,26 @@ func ToUint64E(i interface{}) (uint64, error) {
 func ToUint32E(i interface{}) (uint32, error) {
 	i = indirect(i)
 
-	switch s := i.(type) {
-	case string:
-		v, err := strconv.ParseUint(s, 0, 32)
-		if err == nil {
-			return uint32(v), nil
-		}
-		return 0, fmt.Errorf("unable to cast %#v to uint32: %s", i, err)
-	case int:
-		if s < 0 {
+	intv, ok := toInt(i)
+	if ok {
+		if intv < 0 {
 			return 0, errNegativeNotAllowed
 		}
-		return uint32(s), nil
+		return uint32(intv), nil
+	}
+
+	switch s := i.(type) {
+	case string:
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
+		if err == nil {
+			if v < 0 {
+				return 0, errNegativeNotAllowed
+			}
+			return uint32(v), nil
+		}
+		return 0, fmt.Errorf("unable to cast %#v of type %T to uint32", i, i)
+	case json.Number:
+		return ToUint32E(string(s))
 	case int64:
 		if s < 0 {
 			return 0, errNegativeNotAllowed
@@ -624,18 +719,26 @@ func ToUint32E(i interface{}) (uint32, error) {
 func ToUint16E(i interface{}) (uint16, error) {
 	i = indirect(i)
 
-	switch s := i.(type) {
-	case string:
-		v, err := strconv.ParseUint(s, 0, 16)
-		if err == nil {
-			return uint16(v), nil
-		}
-		return 0, fmt.Errorf("unable to cast %#v to uint16: %s", i, err)
-	case int:
-		if s < 0 {
+	intv, ok := toInt(i)
+	if ok {
+		if intv < 0 {
 			return 0, errNegativeNotAllowed
 		}
-		return uint16(s), nil
+		return uint16(intv), nil
+	}
+
+	switch s := i.(type) {
+	case string:
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
+		if err == nil {
+			if v < 0 {
+				return 0, errNegativeNotAllowed
+			}
+			return uint16(v), nil
+		}
+		return 0, fmt.Errorf("unable to cast %#v of type %T to uint16", i, i)
+	case json.Number:
+		return ToUint16E(string(s))
 	case int64:
 		if s < 0 {
 			return 0, errNegativeNotAllowed
@@ -692,18 +795,26 @@ func ToUint16E(i interface{}) (uint16, error) {
 func ToUint8E(i interface{}) (uint8, error) {
 	i = indirect(i)
 
-	switch s := i.(type) {
-	case string:
-		v, err := strconv.ParseUint(s, 0, 8)
-		if err == nil {
-			return uint8(v), nil
-		}
-		return 0, fmt.Errorf("unable to cast %#v to uint8: %s", i, err)
-	case int:
-		if s < 0 {
+	intv, ok := toInt(i)
+	if ok {
+		if intv < 0 {
 			return 0, errNegativeNotAllowed
 		}
-		return uint8(s), nil
+		return uint8(intv), nil
+	}
+
+	switch s := i.(type) {
+	case string:
+		v, err := strconv.ParseInt(trimZeroDecimal(s), 0, 0)
+		if err == nil {
+			if v < 0 {
+				return 0, errNegativeNotAllowed
+			}
+			return uint8(v), nil
+		}
+		return 0, fmt.Errorf("unable to cast %#v of type %T to uint8", i, i)
+	case json.Number:
+		return ToUint8E(string(s))
 	case int64:
 		if s < 0 {
 			return 0, errNegativeNotAllowed
@@ -819,15 +930,17 @@ func ToStringE(i interface{}) (string, error) {
 	case int8:
 		return strconv.FormatInt(int64(s), 10), nil
 	case uint:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint64:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint32:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint16:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint8:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
+	case json.Number:
+		return s.String(), nil
 	case []byte:
 		return string(s), nil
 	case template.HTML:
@@ -1129,8 +1242,43 @@ func ToStringSliceE(i interface{}) ([]string, error) {
 		return a, nil
 	case []string:
 		return v, nil
+	case []int8:
+		for _, u := range v {
+			a = append(a, ToString(u))
+		}
+		return a, nil
+	case []int:
+		for _, u := range v {
+			a = append(a, ToString(u))
+		}
+		return a, nil
+	case []int32:
+		for _, u := range v {
+			a = append(a, ToString(u))
+		}
+		return a, nil
+	case []int64:
+		for _, u := range v {
+			a = append(a, ToString(u))
+		}
+		return a, nil
+	case []float32:
+		for _, u := range v {
+			a = append(a, ToString(u))
+		}
+		return a, nil
+	case []float64:
+		for _, u := range v {
+			a = append(a, ToString(u))
+		}
+		return a, nil
 	case string:
 		return strings.Fields(v), nil
+	case []error:
+		for _, err := range i.([]error) {
+			a = append(a, err.Error())
+		}
+		return a, nil
 	case interface{}:
 		str, err := ToStringE(v)
 		if err != nil {
@@ -1204,37 +1352,83 @@ func ToDurationSliceE(i interface{}) ([]time.Duration, error) {
 // predefined list of formats.  If no suitable format is found, an error is
 // returned.
 func StringToDate(s string) (time.Time, error) {
-	return parseDateWith(s, []string{
-		time.RFC3339,
-		"2006-01-02T15:04:05", // iso8601 without timezone
-		time.RFC1123Z,
-		time.RFC1123,
-		time.RFC822Z,
-		time.RFC822,
-		time.RFC850,
-		time.ANSIC,
-		time.UnixDate,
-		time.RubyDate,
-		"2006-01-02 15:04:05.999999999 -0700 MST", // Time.String()
-		"2006-01-02",
-		"02 Jan 2006",
-		"2006-01-02T15:04:05-0700", // RFC3339 without timezone hh:mm colon
-		"2006-01-02 15:04:05 -07:00",
-		"2006-01-02 15:04:05 -0700",
-		"2006-01-02 15:04:05Z07:00", // RFC3339 without T
-		"2006-01-02 15:04:05Z0700",  // RFC3339 without T or timezone hh:mm colon
-		"2006-01-02 15:04:05",
-		time.Kitchen,
-		time.Stamp,
-		time.StampMilli,
-		time.StampMicro,
-		time.StampNano,
-	})
+	return parseDateWith(s, time.UTC, timeFormats)
+}
+
+// StringToDateInDefaultLocation casts an empty interface to a time.Time,
+// interpreting inputs without a timezone to be in the given location,
+// or the local timezone if nil.
+func StringToDateInDefaultLocation(s string, location *time.Location) (time.Time, error) {
+	return parseDateWith(s, location, timeFormats)
+}
+
+type timeFormatType int
+
+const (
+	timeFormatNoTimezone timeFormatType = iota
+	timeFormatNamedTimezone
+	timeFormatNumericTimezone
+	timeFormatNumericAndNamedTimezone
+	timeFormatTimeOnly
+)
+
+type timeFormat struct {
+	format string
+	typ    timeFormatType
+}
+
+func (f timeFormat) hasTimezone() bool {
+	// We don't include the formats with only named timezones, see
+	// https://github.com/golang/go/issues/19694#issuecomment-289103522
+	return f.typ >= timeFormatNumericTimezone && f.typ <= timeFormatNumericAndNamedTimezone
+}
+
+var (
+	timeFormats = []timeFormat{
+		{time.RFC3339, timeFormatNumericTimezone},
+		{"2006-01-02T15:04:05", timeFormatNoTimezone}, // iso8601 without timezone
+		{time.RFC1123Z, timeFormatNumericTimezone},
+		{time.RFC1123, timeFormatNamedTimezone},
+		{time.RFC822Z, timeFormatNumericTimezone},
+		{time.RFC822, timeFormatNamedTimezone},
+		{time.RFC850, timeFormatNamedTimezone},
+		{"2006-01-02 15:04:05.999999999 -0700 MST", timeFormatNumericAndNamedTimezone}, // Time.String()
+		{"2006-01-02T15:04:05-0700", timeFormatNumericTimezone},                        // RFC3339 without timezone hh:mm colon
+		{"2006-01-02 15:04:05Z0700", timeFormatNumericTimezone},                        // RFC3339 without T or timezone hh:mm colon
+		{"2006-01-02 15:04:05", timeFormatNoTimezone},
+		{time.ANSIC, timeFormatNoTimezone},
+		{time.UnixDate, timeFormatNamedTimezone},
+		{time.RubyDate, timeFormatNumericTimezone},
+		{"2006-01-02 15:04:05Z07:00", timeFormatNumericTimezone},
+		{"2006-01-02", timeFormatNoTimezone},
+		{"02 Jan 2006", timeFormatNoTimezone},
+		{"2006-01-02 15:04:05 -07:00", timeFormatNumericTimezone},
+		{"2006-01-02 15:04:05 -0700", timeFormatNumericTimezone},
+		{time.Kitchen, timeFormatTimeOnly},
+		{time.Stamp, timeFormatTimeOnly},
+		{time.StampMilli, timeFormatTimeOnly},
+		{time.StampMicro, timeFormatTimeOnly},
+		{time.StampNano, timeFormatTimeOnly},
+	}
+)
+
+func parseDateWith(s string, location *time.Location, formats []timeFormat) (d time.Time, e error) {
+
+	for _, format := range formats {
+		if d, e = time.Parse(format.format, s); e == nil {
+
+			// Some time formats have a zone name, but no offset, so it gets
+			// put in that zone name (not the default one passed in to us), but
+			// without that zone's offset. So set the location manually.
+			if format.typ <= timeFormatNamedTimezone {
+				if location == nil {
+					location = time.Local
+				}
+				year, month, day := d.Date()
+				hour, min, sec := d.Clock()
+				d = time.Date(year, month, day, hour, min, sec, d.Nanosecond(), location)
 			}
 
-func parseDateWith(s string, dates []string) (d time.Time, e error) {
-	for _, dateType := range dates {
-		if d, e = time.Parse(dateType, s); e == nil {
 			return
 		}
 	}
@@ -1247,3 +1441,36 @@ func jsonStringToObject(s string, v interface{}) error {
 	data := []byte(s)
 	return json.Unmarshal(data, v)
 }
+
+// toInt returns the int value of v if v or v's underlying type
+// is an int.
+// Note that this will return false for int64 etc. types.
+func toInt(v interface{}) (int, bool) {
+	switch v := v.(type) {
+	case int:
+		return v, true
+	case time.Weekday:
+		return int(v), true
+	case time.Month:
+		return int(v), true
+	default:
+		return 0, false
+	}
+}
+
+func trimZeroDecimal(s string) string {
+	var foundZero bool
+	for i := len(s); i > 0; i-- {
+		switch s[i-1] {
+		case '.':
+			if foundZero {
+				return s[:i-1]
+			}
+		case '0':
+			foundZero = true
+		default:
+			return s
+		}
+	}
+	return s
+}

go.mod

@@ -1,7 +1,13 @@
-module github.com/spf13/cast
+module git.internal/re/cast
+
+go 1.18
+
+require github.com/frankban/quicktest v1.14.3
 
 require (
-	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/testify v1.2.2
+	github.com/google/go-cmp v0.5.7 // indirect
+	github.com/kr/pretty v0.3.0 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/rogpeppe/go-internal v1.6.1 // indirect
+	golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 // indirect
 )

go.sum

@@ -1,6 +1,18 @@
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
-github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/frankban/quicktest v1.14.3 h1:FJKSZTDHjyhriyC81FLQ0LY93eSai0ZyR/ZIkd3ZUKE=
+github.com/frankban/quicktest v1.14.3/go.mod h1:mgiwOwqx65TmIk1wJ6Q7wvnVMocbUorkibMOrVTHZps=
+github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/rogpeppe/go-internal v1.6.1 h1:/FiVV8dS/e+YqF2JvO3yXRFbBLTIuSDkuC7aBOAvL+k=
+github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=

timeformattype_string.go

@@ -0,0 +1,27 @@
+// Code generated by "stringer -type timeFormatType"; DO NOT EDIT.
+
+package cast
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[timeFormatNoTimezone-0]
+	_ = x[timeFormatNamedTimezone-1]
+	_ = x[timeFormatNumericTimezone-2]
+	_ = x[timeFormatNumericAndNamedTimezone-3]
+	_ = x[timeFormatTimeOnly-4]
+}
+
+const _timeFormatType_name = "timeFormatNoTimezonetimeFormatNamedTimezonetimeFormatNumericTimezonetimeFormatNumericAndNamedTimezonetimeFormatTimeOnly"
+
+var _timeFormatType_index = [...]uint8{0, 20, 43, 68, 101, 119}
+
+func (i timeFormatType) String() string {
+	if i < 0 || i >= timeFormatType(len(_timeFormatType_index)-1) {
+		return "timeFormatType(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _timeFormatType_name[_timeFormatType_index[i]:_timeFormatType_index[i+1]]
+}