Enhance regex patterns

- Used non-capturing groups when the info is not relevant
- Simplified some expressions

Signed-off-by: Adrian Orive <adrian.orive.oneca@gmail.com>

pkg/internal/validation/dns.go

@@ -26,9 +26,9 @@ import (
 // "k8s.io/apimachinery" is needed, re-consider whether to add the dependency.
 
 const (
-	dns1123LabelFmt     string = "[a-z0-9]([-a-z0-9]*[a-z0-9])?"
+	dns1123LabelFmt     string = "[a-z0-9](?:[-a-z0-9]*[a-z0-9])?"
 	dns1123SubdomainFmt string = dns1123LabelFmt + "(\\." + dns1123LabelFmt + ")*"
-	dns1035LabelFmt     string = "[a-z]([-a-z0-9]*[a-z0-9])?"
+	dns1035LabelFmt     string = "[a-z](?:[-a-z0-9]*[a-z0-9])?"
 )
 
 type dnsValidationConfig struct {

pkg/internal/validation/project.go

@@ -22,7 +22,7 @@ import (
 )
 
 // projectVersionFmt defines the project version format from a project config.
-const projectVersionFmt string = "[1-9][0-9]*(-(alpha|beta))?"
+const projectVersionFmt string = "[1-9][0-9]*(?:-(?:alpha|beta))?"
 
 var projectVersionRe = regexp.MustCompile("^" + projectVersionFmt + "$")
 

pkg/model/resource/options.go

@@ -29,7 +29,7 @@ import (
 )
 
 const (
-	versionPattern  = "^v\\d+(alpha\\d+|beta\\d+)?$"
+	versionPattern  = "^v\\d+(?:alpha\\d+|beta\\d+)?$"
 	groupRequired   = "group cannot be empty"
 	versionRequired = "version cannot be empty"
 	kindRequired    = "kind cannot be empty"

pkg/plugin/internal/util/go_version.go

@@ -54,7 +54,7 @@ func fetchAndCheckGoVersion() error {
 // checkGoVersion should only ever check if the Go version >= 1.13, since the kubebuilder binary only cares
 // that the go binary supports go modules which were stabilized in that version (i.e. in go 1.13) by default
 func checkGoVersion(verStr string) error {
-	goVerRegex := `^go?([0-9]+)\.([0-9]+)([\.0-9A-Za-z\-]+)?$`
+	goVerRegex := `^go?([0-9]+)\.([0-9]+)[\.0-9A-Za-z\-]*$`
 	m := regexp.MustCompile(goVerRegex).FindStringSubmatch(verStr)
 	if m == nil {
 		return fmt.Errorf("invalid version string")

pkg/plugin/plugin.go

@@ -39,7 +39,7 @@ const (
 )
 
 // verRe defines the string format of a version.
-var verRe = regexp.MustCompile("^(v)?([1-9][0-9]*)(-alpha|-beta)?$")
+var verRe = regexp.MustCompile("^v?([1-9][0-9]*)(?:-(alpha|beta))?$")
 
 // Version is a plugin version containing a non-zero integer and an optional stage value
 // that if present identifies a version as not stable to some degree.
@@ -75,15 +75,15 @@ func ParseVersion(version string) (v Version, err error) {
 		return v, errors.New("plugin version is empty")
 	}
 
-	// A valid version string will have 4 submatches, each of which may be empty: the full string, "v",
-	// the integer, and the stage suffix. Invalid version strings do not have 4 submatches.
+	// A valid version string will have 3 submatches, each of which may be empty: the full string,
+	// the integer, and the stage suffix. Invalid version strings do not have 3 submatches.
 	submatches := verRe.FindStringSubmatch(version)
-	if len(submatches) != 4 {
+	if len(submatches) != 3 {
 		return v, fmt.Errorf("version format must match %s", verRe.String())
 	}
 
 	// Parse version number.
-	versionNumStr := submatches[2]
+	versionNumStr := submatches[1]
 	if versionNumStr == "" {
 		return v, errors.New("version must contain an integer")
 	}
@@ -92,7 +92,7 @@ func ParseVersion(version string) (v Version, err error) {
 	}
 
 	// Parse stage suffix, if any.
-	v.Stage = strings.TrimPrefix(submatches[3], "-")
+	v.Stage = submatches[2]
 
 	return v, v.Validate()
 }