fix(*): Vendored project dependencies

vendor/github.com/hashicorp/go-version/constraint.go

@@ -0,0 +1,296 @@
+package version
+
+import (
+	"fmt"
+	"reflect"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+// Constraint represents a single constraint for a version, such as
+// ">= 1.0".
+type Constraint struct {
+	f        constraintFunc
+	op       operator
+	check    *Version
+	original string
+}
+
+func (c *Constraint) Equals(con *Constraint) bool {
+	return c.op == con.op && c.check.Equal(con.check)
+}
+
+// Constraints is a slice of constraints. We make a custom type so that
+// we can add methods to it.
+type Constraints []*Constraint
+
+type constraintFunc func(v, c *Version) bool
+
+var constraintOperators map[string]constraintOperation
+
+type constraintOperation struct {
+	op operator
+	f  constraintFunc
+}
+
+var constraintRegexp *regexp.Regexp
+
+func init() {
+	constraintOperators = map[string]constraintOperation{
+		"":   {op: equal, f: constraintEqual},
+		"=":  {op: equal, f: constraintEqual},
+		"!=": {op: notEqual, f: constraintNotEqual},
+		">":  {op: greaterThan, f: constraintGreaterThan},
+		"<":  {op: lessThan, f: constraintLessThan},
+		">=": {op: greaterThanEqual, f: constraintGreaterThanEqual},
+		"<=": {op: lessThanEqual, f: constraintLessThanEqual},
+		"~>": {op: pessimistic, f: constraintPessimistic},
+	}
+
+	ops := make([]string, 0, len(constraintOperators))
+	for k := range constraintOperators {
+		ops = append(ops, regexp.QuoteMeta(k))
+	}
+
+	constraintRegexp = regexp.MustCompile(fmt.Sprintf(
+		`^\s*(%s)\s*(%s)\s*$`,
+		strings.Join(ops, "|"),
+		VersionRegexpRaw))
+}
+
+// NewConstraint will parse one or more constraints from the given
+// constraint string. The string must be a comma-separated list of
+// constraints.
+func NewConstraint(v string) (Constraints, error) {
+	vs := strings.Split(v, ",")
+	result := make([]*Constraint, len(vs))
+	for i, single := range vs {
+		c, err := parseSingle(single)
+		if err != nil {
+			return nil, err
+		}
+
+		result[i] = c
+	}
+
+	return Constraints(result), nil
+}
+
+// MustConstraints is a helper that wraps a call to a function
+// returning (Constraints, error) and panics if error is non-nil.
+func MustConstraints(c Constraints, err error) Constraints {
+	if err != nil {
+		panic(err)
+	}
+
+	return c
+}
+
+// Check tests if a version satisfies all the constraints.
+func (cs Constraints) Check(v *Version) bool {
+	for _, c := range cs {
+		if !c.Check(v) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Equals compares Constraints with other Constraints
+// for equality. This may not represent logical equivalence
+// of compared constraints.
+// e.g. even though '>0.1,>0.2' is logically equivalent
+// to '>0.2' it is *NOT* treated as equal.
+//
+// Missing operator is treated as equal to '=', whitespaces
+// are ignored and constraints are sorted before comaparison.
+func (cs Constraints) Equals(c Constraints) bool {
+	if len(cs) != len(c) {
+		return false
+	}
+
+	// make copies to retain order of the original slices
+	left := make(Constraints, len(cs))
+	copy(left, cs)
+	sort.Stable(left)
+	right := make(Constraints, len(c))
+	copy(right, c)
+	sort.Stable(right)
+
+	// compare sorted slices
+	for i, con := range left {
+		if !con.Equals(right[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (cs Constraints) Len() int {
+	return len(cs)
+}
+
+func (cs Constraints) Less(i, j int) bool {
+	if cs[i].op < cs[j].op {
+		return true
+	}
+	if cs[i].op > cs[j].op {
+		return false
+	}
+
+	return cs[i].check.LessThan(cs[j].check)
+}
+
+func (cs Constraints) Swap(i, j int) {
+	cs[i], cs[j] = cs[j], cs[i]
+}
+
+// Returns the string format of the constraints
+func (cs Constraints) String() string {
+	csStr := make([]string, len(cs))
+	for i, c := range cs {
+		csStr[i] = c.String()
+	}
+
+	return strings.Join(csStr, ",")
+}
+
+// Check tests if a constraint is validated by the given version.
+func (c *Constraint) Check(v *Version) bool {
+	return c.f(v, c.check)
+}
+
+// Prerelease returns true if the version underlying this constraint
+// contains a prerelease field.
+func (c *Constraint) Prerelease() bool {
+	return len(c.check.Prerelease()) > 0
+}
+
+func (c *Constraint) String() string {
+	return c.original
+}
+
+func parseSingle(v string) (*Constraint, error) {
+	matches := constraintRegexp.FindStringSubmatch(v)
+	if matches == nil {
+		return nil, fmt.Errorf("Malformed constraint: %s", v)
+	}
+
+	check, err := NewVersion(matches[2])
+	if err != nil {
+		return nil, err
+	}
+
+	cop := constraintOperators[matches[1]]
+
+	return &Constraint{
+		f:        cop.f,
+		op:       cop.op,
+		check:    check,
+		original: v,
+	}, nil
+}
+
+func prereleaseCheck(v, c *Version) bool {
+	switch vPre, cPre := v.Prerelease() != "", c.Prerelease() != ""; {
+	case cPre && vPre:
+		// A constraint with a pre-release can only match a pre-release version
+		// with the same base segments.
+		return reflect.DeepEqual(c.Segments64(), v.Segments64())
+
+	case !cPre && vPre:
+		// A constraint without a pre-release can only match a version without a
+		// pre-release.
+		return false
+
+	case cPre && !vPre:
+		// OK, except with the pessimistic operator
+	case !cPre && !vPre:
+		// OK
+	}
+	return true
+}
+
+//-------------------------------------------------------------------
+// Constraint functions
+//-------------------------------------------------------------------
+
+type operator rune
+
+const (
+	equal            operator = '='
+	notEqual         operator = '≠'
+	greaterThan      operator = '>'
+	lessThan         operator = '<'
+	greaterThanEqual operator = '≥'
+	lessThanEqual    operator = '≤'
+	pessimistic      operator = '~'
+)
+
+func constraintEqual(v, c *Version) bool {
+	return v.Equal(c)
+}
+
+func constraintNotEqual(v, c *Version) bool {
+	return !v.Equal(c)
+}
+
+func constraintGreaterThan(v, c *Version) bool {
+	return prereleaseCheck(v, c) && v.Compare(c) == 1
+}
+
+func constraintLessThan(v, c *Version) bool {
+	return prereleaseCheck(v, c) && v.Compare(c) == -1
+}
+
+func constraintGreaterThanEqual(v, c *Version) bool {
+	return prereleaseCheck(v, c) && v.Compare(c) >= 0
+}
+
+func constraintLessThanEqual(v, c *Version) bool {
+	return prereleaseCheck(v, c) && v.Compare(c) <= 0
+}
+
+func constraintPessimistic(v, c *Version) bool {
+	// Using a pessimistic constraint with a pre-release, restricts versions to pre-releases
+	if !prereleaseCheck(v, c) || (c.Prerelease() != "" && v.Prerelease() == "") {
+		return false
+	}
+
+	// If the version being checked is naturally less than the constraint, then there
+	// is no way for the version to be valid against the constraint
+	if v.LessThan(c) {
+		return false
+	}
+	// We'll use this more than once, so grab the length now so it's a little cleaner
+	// to write the later checks
+	cs := len(c.segments)
+
+	// If the version being checked has less specificity than the constraint, then there
+	// is no way for the version to be valid against the constraint
+	if cs > len(v.segments) {
+		return false
+	}
+
+	// Check the segments in the constraint against those in the version. If the version
+	// being checked, at any point, does not have the same values in each index of the
+	// constraints segments, then it cannot be valid against the constraint.
+	for i := 0; i < c.si-1; i++ {
+		if v.segments[i] != c.segments[i] {
+			return false
+		}
+	}
+
+	// Check the last part of the segment in the constraint. If the version segment at
+	// this index is less than the constraints segment at this index, then it cannot
+	// be valid against the constraint
+	if c.segments[cs-1] > v.segments[cs-1] {
+		return false
+	}
+
+	// If nothing has rejected the version by now, it's valid
+	return true
+}