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package semver
import (
"errors"
"fmt"
"regexp"
"strings"
)
// Constraints is one or more constraint that a semantic version can be
// checked against.
type Constraints struct {
constraints [][]*constraint
}
// NewConstraint returns a Constraints instance that a Version instance can
// be checked against. If there is a parse error it will be returned.
func NewConstraint(c string) (*Constraints, error) {
// Rewrite - ranges into a comparison operation.
c = rewriteRange(c)
ors := strings.Split(c, "||")
or := make([][]*constraint, len(ors))
for k, v := range ors {
cs := strings.Split(v, ",")
result := make([]*constraint, len(cs))
for i, s := range cs {
pc, err := parseConstraint(s)
if err != nil {
return nil, err
}
result[i] = pc
}
or[k] = result
}
o := &Constraints{constraints: or}
return o, nil
}
// Check tests if a version satisfies the constraints.
func (cs Constraints) Check(v *Version) bool {
// loop over the ORs and check the inner ANDs
for _, o := range cs.constraints {
joy := true
for _, c := range o {
if !c.check(v) {
joy = false
break
}
}
if joy {
return true
}
}
return false
}
// Validate checks if a version satisfies a constraint. If not a slice of
// reasons for the failure are returned in addition to a bool.
func (cs Constraints) Validate(v *Version) (bool, []error) {
// loop over the ORs and check the inner ANDs
var e []error
for _, o := range cs.constraints {
joy := true
for _, c := range o {
if !c.check(v) {
em := fmt.Errorf(c.msg, v, c.orig)
e = append(e, em)
joy = false
}
}
if joy {
return true, []error{}
}
}
return false, e
}
var constraintOps map[string]cfunc
var constraintMsg map[string]string
var constraintRegex *regexp.Regexp
func init() {
constraintOps = map[string]cfunc{
"": constraintTildeOrEqual,
"=": constraintTildeOrEqual,
"!=": constraintNotEqual,
">": constraintGreaterThan,
"<": constraintLessThan,
">=": constraintGreaterThanEqual,
"=>": constraintGreaterThanEqual,
"<=": constraintLessThanEqual,
"=<": constraintLessThanEqual,
"~": constraintTilde,
"~>": constraintTilde,
"^": constraintCaret,
}
constraintMsg = map[string]string{
"": "%s is not equal to %s",
"=": "%s is not equal to %s",
"!=": "%s is equal to %s",
">": "%s is less than or equal to %s",
"<": "%s is greater than or equal to %s",
">=": "%s is less than %s",
"=>": "%s is less than %s",
"<=": "%s is greater than %s",
"=<": "%s is greater than %s",
"~": "%s does not have same major and minor version as %s",
"~>": "%s does not have same major and minor version as %s",
"^": "%s does not have same major version as %s",
}
ops := make([]string, 0, len(constraintOps))
for k := range constraintOps {
ops = append(ops, regexp.QuoteMeta(k))
}
constraintRegex = regexp.MustCompile(fmt.Sprintf(
`^\s*(%s)\s*(%s)\s*$`,
strings.Join(ops, "|"),
cvRegex))
constraintRangeRegex = regexp.MustCompile(fmt.Sprintf(
`\s*(%s)\s+-\s+(%s)\s*`,
cvRegex, cvRegex))
}
// An individual constraint
type constraint struct {
// The callback function for the restraint. It performs the logic for
// the constraint.
function cfunc
msg string
// The version used in the constraint check. For example, if a constraint
// is '<= 2.0.0' the con a version instance representing 2.0.0.
con *Version
// The original parsed version (e.g., 4.x from != 4.x)
orig string
// When an x is used as part of the version (e.g., 1.x)
minorDirty bool
dirty bool
patchDirty bool
}
// Check if a version meets the constraint
func (c *constraint) check(v *Version) bool {
return c.function(v, c)
}
type cfunc func(v *Version, c *constraint) bool
func parseConstraint(c string) (*constraint, error) {
m := constraintRegex.FindStringSubmatch(c)
if m == nil {
return nil, fmt.Errorf("improper constraint: %s", c)
}
ver := m[2]
orig := ver
minorDirty := false
patchDirty := false
dirty := false
if isX(m[3]) {
ver = "0.0.0"
dirty = true
} else if isX(strings.TrimPrefix(m[4], ".")) || m[4] == "" {
minorDirty = true
dirty = true
ver = fmt.Sprintf("%s.0.0%s", m[3], m[6])
} else if isX(strings.TrimPrefix(m[5], ".")) {
dirty = true
patchDirty = true
ver = fmt.Sprintf("%s%s.0%s", m[3], m[4], m[6])
}
con, err := NewVersion(ver)
if err != nil {
// The constraintRegex should catch any regex parsing errors. So,
// we should never get here.
return nil, errors.New("constraint Parser Error")
}
cs := &constraint{
function: constraintOps[m[1]],
msg: constraintMsg[m[1]],
con: con,
orig: orig,
minorDirty: minorDirty,
patchDirty: patchDirty,
dirty: dirty,
}
return cs, nil
}
// Constraint functions
func constraintNotEqual(v *Version, c *constraint) bool {
if c.dirty {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
if c.con.Major() != v.Major() {
return true
}
if c.con.Minor() != v.Minor() && !c.minorDirty {
return true
} else if c.minorDirty {
return false
}
return false
}
return !v.Equal(c.con)
}
func constraintGreaterThan(v *Version, c *constraint) bool {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
return v.Compare(c.con) == 1
}
func constraintLessThan(v *Version, c *constraint) bool {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
if !c.dirty {
return v.Compare(c.con) < 0
}
if v.Major() > c.con.Major() {
return false
} else if v.Minor() > c.con.Minor() && !c.minorDirty {
return false
}
return true
}
func constraintGreaterThanEqual(v *Version, c *constraint) bool {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
return v.Compare(c.con) >= 0
}
func constraintLessThanEqual(v *Version, c *constraint) bool {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
if !c.dirty {
return v.Compare(c.con) <= 0
}
if v.Major() > c.con.Major() {
return false
} else if v.Minor() > c.con.Minor() && !c.minorDirty {
return false
}
return true
}
// ~*, ~>* --> >= 0.0.0 (any)
// ~2, ~2.x, ~2.x.x, ~>2, ~>2.x ~>2.x.x --> >=2.0.0, <3.0.0
// ~2.0, ~2.0.x, ~>2.0, ~>2.0.x --> >=2.0.0, <2.1.0
// ~1.2, ~1.2.x, ~>1.2, ~>1.2.x --> >=1.2.0, <1.3.0
// ~1.2.3, ~>1.2.3 --> >=1.2.3, <1.3.0
// ~1.2.0, ~>1.2.0 --> >=1.2.0, <1.3.0
func constraintTilde(v *Version, c *constraint) bool {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
if v.LessThan(c.con) {
return false
}
// ~0.0.0 is a special case where all constraints are accepted. It's
// equivalent to >= 0.0.0.
if c.con.Major() == 0 && c.con.Minor() == 0 && c.con.Patch() == 0 &&
!c.minorDirty && !c.patchDirty {
return true
}
if v.Major() != c.con.Major() {
return false
}
if v.Minor() != c.con.Minor() && !c.minorDirty {
return false
}
return true
}
// When there is a .x (dirty) status it automatically opts in to ~. Otherwise
// it's a straight =
func constraintTildeOrEqual(v *Version, c *constraint) bool {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
if c.dirty {
c.msg = constraintMsg["~"]
return constraintTilde(v, c)
}
return v.Equal(c.con)
}
// ^* --> (any)
// ^2, ^2.x, ^2.x.x --> >=2.0.0, <3.0.0
// ^2.0, ^2.0.x --> >=2.0.0, <3.0.0
// ^1.2, ^1.2.x --> >=1.2.0, <2.0.0
// ^1.2.3 --> >=1.2.3, <2.0.0
// ^1.2.0 --> >=1.2.0, <2.0.0
func constraintCaret(v *Version, c *constraint) bool {
// If there is a pre-release on the version but the constraint isn't looking
// for them assume that pre-releases are not compatible. See issue 21 for
// more details.
if v.Prerelease() != "" && c.con.Prerelease() == "" {
return false
}
if v.LessThan(c.con) {
return false
}
if v.Major() != c.con.Major() {
return false
}
return true
}
var constraintRangeRegex *regexp.Regexp
const cvRegex string = `v?([0-9|x|X|\*]+)(\.[0-9|x|X|\*]+)?(\.[0-9|x|X|\*]+)?` +
`(-([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*))?` +
`(\+([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*))?`
func isX(x string) bool {
switch x {
case "x", "*", "X":
return true
default:
return false
}
}
func rewriteRange(i string) string {
m := constraintRangeRegex.FindAllStringSubmatch(i, -1)
if m == nil {
return i
}
o := i
for _, v := range m {
t := fmt.Sprintf(">= %s, <= %s", v[1], v[11])
o = strings.Replace(o, v[0], t, 1)
}
return o
}
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