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Jeremy Carroll Added $ to ValidPrerelease 5be2a7f Nov 11, 2018
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@mattfarina @mh-cbon @zknill @uudashr @sdboyer @maroux @adamreese
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package semver
import (
"bytes"
"encoding/json"
"errors"
"fmt"
"regexp"
"strconv"
"strings"
)
// The compiled version of the regex created at init() is cached here so it
// only needs to be created once.
var versionRegex *regexp.Regexp
var validPrereleaseRegex *regexp.Regexp
var (
// ErrInvalidSemVer is returned a version is found to be invalid when
// being parsed.
ErrInvalidSemVer = errors.New("Invalid Semantic Version")
// ErrInvalidMetadata is returned when the metadata is an invalid format
ErrInvalidMetadata = errors.New("Invalid Metadata string")
// ErrInvalidPrerelease is returned when the pre-release is an invalid format
ErrInvalidPrerelease = errors.New("Invalid Prerelease string")
)
// SemVerRegex is the regular expression used to parse a semantic version.
const SemVerRegex string = `v?([0-9]+)(\.[0-9]+)?(\.[0-9]+)?` +
`(-([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*))?` +
`(\+([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*))?`
// ValidPrerelease is the regular expression which validates
// both prerelease and metadata values.
const ValidPrerelease string = `^([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*)$`
// Version represents a single semantic version.
type Version struct {
major, minor, patch int64
pre string
metadata string
original string
}
func init() {
versionRegex = regexp.MustCompile("^" + SemVerRegex + "$")
validPrereleaseRegex = regexp.MustCompile(ValidPrerelease)
}
// NewVersion parses a given version and returns an instance of Version or
// an error if unable to parse the version.
func NewVersion(v string) (*Version, error) {
m := versionRegex.FindStringSubmatch(v)
if m == nil {
return nil, ErrInvalidSemVer
}
sv := &Version{
metadata: m[8],
pre: m[5],
original: v,
}
var temp int64
temp, err := strconv.ParseInt(m[1], 10, 64)
if err != nil {
return nil, fmt.Errorf("Error parsing version segment: %s", err)
}
sv.major = temp
if m[2] != "" {
temp, err = strconv.ParseInt(strings.TrimPrefix(m[2], "."), 10, 64)
if err != nil {
return nil, fmt.Errorf("Error parsing version segment: %s", err)
}
sv.minor = temp
} else {
sv.minor = 0
}
if m[3] != "" {
temp, err = strconv.ParseInt(strings.TrimPrefix(m[3], "."), 10, 64)
if err != nil {
return nil, fmt.Errorf("Error parsing version segment: %s", err)
}
sv.patch = temp
} else {
sv.patch = 0
}
return sv, nil
}
// MustParse parses a given version and panics on error.
func MustParse(v string) *Version {
sv, err := NewVersion(v)
if err != nil {
panic(err)
}
return sv
}
// String converts a Version object to a string.
// Note, if the original version contained a leading v this version will not.
// See the Original() method to retrieve the original value. Semantic Versions
// don't contain a leading v per the spec. Instead it's optional on
// implementation.
func (v *Version) String() string {
var buf bytes.Buffer
fmt.Fprintf(&buf, "%d.%d.%d", v.major, v.minor, v.patch)
if v.pre != "" {
fmt.Fprintf(&buf, "-%s", v.pre)
}
if v.metadata != "" {
fmt.Fprintf(&buf, "+%s", v.metadata)
}
return buf.String()
}
// Original returns the original value passed in to be parsed.
func (v *Version) Original() string {
return v.original
}
// Major returns the major version.
func (v *Version) Major() int64 {
return v.major
}
// Minor returns the minor version.
func (v *Version) Minor() int64 {
return v.minor
}
// Patch returns the patch version.
func (v *Version) Patch() int64 {
return v.patch
}
// Prerelease returns the pre-release version.
func (v *Version) Prerelease() string {
return v.pre
}
// Metadata returns the metadata on the version.
func (v *Version) Metadata() string {
return v.metadata
}
// originalVPrefix returns the original 'v' prefix if any.
func (v *Version) originalVPrefix() string {
// Note, only lowercase v is supported as a prefix by the parser.
if v.original != "" && v.original[:1] == "v" {
return v.original[:1]
}
return ""
}
// IncPatch produces the next patch version.
// If the current version does not have prerelease/metadata information,
// it unsets metadata and prerelease values, increments patch number.
// If the current version has any of prerelease or metadata information,
// it unsets both values and keeps curent patch value
func (v Version) IncPatch() Version {
vNext := v
// according to http://semver.org/#spec-item-9
// Pre-release versions have a lower precedence than the associated normal version.
// according to http://semver.org/#spec-item-10
// Build metadata SHOULD be ignored when determining version precedence.
if v.pre != "" {
vNext.metadata = ""
vNext.pre = ""
} else {
vNext.metadata = ""
vNext.pre = ""
vNext.patch = v.patch + 1
}
vNext.original = v.originalVPrefix() + "" + vNext.String()
return vNext
}
// IncMinor produces the next minor version.
// Sets patch to 0.
// Increments minor number.
// Unsets metadata.
// Unsets prerelease status.
func (v Version) IncMinor() Version {
vNext := v
vNext.metadata = ""
vNext.pre = ""
vNext.patch = 0
vNext.minor = v.minor + 1
vNext.original = v.originalVPrefix() + "" + vNext.String()
return vNext
}
// IncMajor produces the next major version.
// Sets patch to 0.
// Sets minor to 0.
// Increments major number.
// Unsets metadata.
// Unsets prerelease status.
func (v Version) IncMajor() Version {
vNext := v
vNext.metadata = ""
vNext.pre = ""
vNext.patch = 0
vNext.minor = 0
vNext.major = v.major + 1
vNext.original = v.originalVPrefix() + "" + vNext.String()
return vNext
}
// SetPrerelease defines the prerelease value.
// Value must not include the required 'hypen' prefix.
func (v Version) SetPrerelease(prerelease string) (Version, error) {
vNext := v
if len(prerelease) > 0 && !validPrereleaseRegex.MatchString(prerelease) {
return vNext, ErrInvalidPrerelease
}
vNext.pre = prerelease
vNext.original = v.originalVPrefix() + "" + vNext.String()
return vNext, nil
}
// SetMetadata defines metadata value.
// Value must not include the required 'plus' prefix.
func (v Version) SetMetadata(metadata string) (Version, error) {
vNext := v
if len(metadata) > 0 && !validPrereleaseRegex.MatchString(metadata) {
return vNext, ErrInvalidMetadata
}
vNext.metadata = metadata
vNext.original = v.originalVPrefix() + "" + vNext.String()
return vNext, nil
}
// LessThan tests if one version is less than another one.
func (v *Version) LessThan(o *Version) bool {
return v.Compare(o) < 0
}
// GreaterThan tests if one version is greater than another one.
func (v *Version) GreaterThan(o *Version) bool {
return v.Compare(o) > 0
}
// Equal tests if two versions are equal to each other.
// Note, versions can be equal with different metadata since metadata
// is not considered part of the comparable version.
func (v *Version) Equal(o *Version) bool {
return v.Compare(o) == 0
}
// Compare compares this version to another one. It returns -1, 0, or 1 if
// the version smaller, equal, or larger than the other version.
//
// Versions are compared by X.Y.Z. Build metadata is ignored. Prerelease is
// lower than the version without a prerelease.
func (v *Version) Compare(o *Version) int {
// Compare the major, minor, and patch version for differences. If a
// difference is found return the comparison.
if d := compareSegment(v.Major(), o.Major()); d != 0 {
return d
}
if d := compareSegment(v.Minor(), o.Minor()); d != 0 {
return d
}
if d := compareSegment(v.Patch(), o.Patch()); d != 0 {
return d
}
// At this point the major, minor, and patch versions are the same.
ps := v.pre
po := o.Prerelease()
if ps == "" && po == "" {
return 0
}
if ps == "" {
return 1
}
if po == "" {
return -1
}
return comparePrerelease(ps, po)
}
// UnmarshalJSON implements JSON.Unmarshaler interface.
func (v *Version) UnmarshalJSON(b []byte) error {
var s string
if err := json.Unmarshal(b, &s); err != nil {
return err
}
temp, err := NewVersion(s)
if err != nil {
return err
}
v.major = temp.major
v.minor = temp.minor
v.patch = temp.patch
v.pre = temp.pre
v.metadata = temp.metadata
v.original = temp.original
temp = nil
return nil
}
// MarshalJSON implements JSON.Marshaler interface.
func (v *Version) MarshalJSON() ([]byte, error) {
return json.Marshal(v.String())
}
func compareSegment(v, o int64) int {
if v < o {
return -1
}
if v > o {
return 1
}
return 0
}
func comparePrerelease(v, o string) int {
// split the prelease versions by their part. The separator, per the spec,
// is a .
sparts := strings.Split(v, ".")
oparts := strings.Split(o, ".")
// Find the longer length of the parts to know how many loop iterations to
// go through.
slen := len(sparts)
olen := len(oparts)
l := slen
if olen > slen {
l = olen
}
// Iterate over each part of the prereleases to compare the differences.
for i := 0; i < l; i++ {
// Since the lentgh of the parts can be different we need to create
// a placeholder. This is to avoid out of bounds issues.
stemp := ""
if i < slen {
stemp = sparts[i]
}
otemp := ""
if i < olen {
otemp = oparts[i]
}
d := comparePrePart(stemp, otemp)
if d != 0 {
return d
}
}
// Reaching here means two versions are of equal value but have different
// metadata (the part following a +). They are not identical in string form
// but the version comparison finds them to be equal.
return 0
}
func comparePrePart(s, o string) int {
// Fastpath if they are equal
if s == o {
return 0
}
// When s or o are empty we can use the other in an attempt to determine
// the response.
if s == "" {
if o != "" {
return -1
}
return 1
}
if o == "" {
if s != "" {
return 1
}
return -1
}
// When comparing strings "99" is greater than "103". To handle
// cases like this we need to detect numbers and compare them.
oi, n1 := strconv.ParseInt(o, 10, 64)
si, n2 := strconv.ParseInt(s, 10, 64)
// The case where both are strings compare the strings
if n1 != nil && n2 != nil {
if s > o {
return 1
}
return -1
} else if n1 != nil {
// o is a string and s is a number
return -1
} else if n2 != nil {
// s is a string and o is a number
return 1
}
// Both are numbers
if si > oi {
return 1
}
return -1
}
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