Add property to include prereleases

On the Constraints type there is now a property IncludePrerelease. When set, prereleases will be included when checking or validating constraints. This is additive to the existing behavior where a prerelease in a constraint causes the checks to include prereleases. The existing behavior has not changed. Signed-off-by: Matt Farina <matt.farina@suse.com>

Author: mattfarina

constraints.go

@@ -13,6 +13,12 @@ import (
 type Constraints struct {
 constraints [][]*constraint
 containsPre []bool
+
+// IncludePrerelease specifies if pre-releases should be included in
+// the results. Note, if a constraint range has a prerelease than
+// prereleases will be included for that AND group even if this is
+// set to false.
+IncludePrerelease bool
 }
 
 // NewConstraint returns a Constraints instance that a Version instance can
@@ -70,7 +76,7 @@ func (cs Constraints) Check(v *Version) bool {
 for i, o := range cs.constraints {
 joy := true
 for _, c := range o {
-if check, _ := c.check(v, cs.containsPre[i]); !check {
+if check, _ := c.check(v, (cs.IncludePrerelease || cs.containsPre[i])); !check {
 joy = false
 break
 }
@@ -98,7 +104,7 @@ func (cs Constraints) Validate(v *Version) (bool, []error) {
 for _, c := range o {
 // Before running the check handle the case there the version is
 // a prerelease and the check is not searching for prereleases.
-if !cs.containsPre[i] && v.pre != "" {
+if !(cs.IncludePrerelease || cs.containsPre[i]) && v.pre != "" {
 if !prerelesase {
 em := fmt.Errorf("%s is a prerelease version and the constraint is only looking for release versions", v)
 e = append(e, em)
@@ -108,7 +114,7 @@ func (cs Constraints) Validate(v *Version) (bool, []error) {
 
 } else {
 
-if _, err := c.check(v, cs.containsPre[i]); err != nil {
+if _, err := c.check(v, (cs.IncludePrerelease || cs.containsPre[i])); err != nil {
 e = append(e, err)
 joy = false
 }