Merge pull request #118761 from TommyStarK/gh_113831

move common logic of highestSupportedVersion to util package

staging/src/k8s.io/apimachinery/pkg/util/version/version.go

@@ -18,6 +18,7 @@ package version
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"regexp"
 	"strconv"
@@ -85,6 +86,47 @@ func parse(str string, semver bool) (*Version, error) {
 	return v, nil
 }
 
+// HighestSupportedVersion returns the highest supported version
+// This function assumes that the highest supported version must be v1.x.
+func HighestSupportedVersion(versions []string) (*Version, error) {
+	if len(versions) == 0 {
+		return nil, errors.New("empty array for supported versions")
+	}
+
+	var (
+		highestSupportedVersion *Version
+		theErr                  error
+	)
+
+	for i := len(versions) - 1; i >= 0; i-- {
+		currentHighestVer, err := ParseGeneric(versions[i])
+		if err != nil {
+			theErr = err
+			continue
+		}
+
+		if currentHighestVer.Major() > 1 {
+			continue
+		}
+
+		if highestSupportedVersion == nil || highestSupportedVersion.LessThan(currentHighestVer) {
+			highestSupportedVersion = currentHighestVer
+		}
+	}
+
+	if highestSupportedVersion == nil {
+		return nil, fmt.Errorf(
+			"could not find a highest supported version from versions (%v) reported: %+v",
+			versions, theErr)
+	}
+
+	if highestSupportedVersion.Major() != 1 {
+		return nil, fmt.Errorf("highest supported version reported is %v, must be v1.x", highestSupportedVersion)
+	}
+
+	return highestSupportedVersion, nil
+}
+
 // ParseGeneric parses a "generic" version string. The version string must consist of two
 // or more dot-separated numeric fields (the first of which can't have leading zeroes),
 // followed by arbitrary uninterpreted data (which need not be separated from the final

staging/src/k8s.io/apimachinery/pkg/util/version/version_test.go

@@ -346,3 +346,109 @@ func TestComponents(t *testing.T) {
 		}
 	}
 }
+
+func TestHighestSupportedVersion(t *testing.T) {
+	testCases := []struct {
+		versions                        []string
+		expectedHighestSupportedVersion string
+		shouldFail                      bool
+	}{
+		{
+			versions:                        []string{"v1.0.0"},
+			expectedHighestSupportedVersion: "1.0.0",
+			shouldFail:                      false,
+		},
+		{
+			versions:   []string{"0.3.0"},
+			shouldFail: true,
+		},
+		{
+			versions:   []string{"0.2.0"},
+			shouldFail: true,
+		},
+		{
+			versions:                        []string{"1.0.0"},
+			expectedHighestSupportedVersion: "1.0.0",
+			shouldFail:                      false,
+		},
+		{
+			versions:   []string{"v0.3.0"},
+			shouldFail: true,
+		},
+		{
+			versions:   []string{"v0.2.0"},
+			shouldFail: true,
+		},
+		{
+			versions:   []string{"0.2.0", "v0.3.0"},
+			shouldFail: true,
+		},
+		{
+			versions:                        []string{"0.2.0", "v1.0.0"},
+			expectedHighestSupportedVersion: "1.0.0",
+			shouldFail:                      false,
+		},
+		{
+			versions:                        []string{"0.2.0", "v1.2.3"},
+			expectedHighestSupportedVersion: "1.2.3",
+			shouldFail:                      false,
+		},
+		{
+			versions:                        []string{"v1.2.3", "v0.3.0"},
+			expectedHighestSupportedVersion: "1.2.3",
+			shouldFail:                      false,
+		},
+		{
+			versions:                        []string{"v1.2.3", "v0.3.0", "2.0.1"},
+			expectedHighestSupportedVersion: "1.2.3",
+			shouldFail:                      false,
+		},
+		{
+			versions:                        []string{"v1.2.3", "4.9.12", "v0.3.0", "2.0.1"},
+			expectedHighestSupportedVersion: "1.2.3",
+			shouldFail:                      false,
+		},
+		{
+			versions:                        []string{"4.9.12", "2.0.1"},
+			expectedHighestSupportedVersion: "",
+			shouldFail:                      true,
+		},
+		{
+			versions:                        []string{"v1.2.3", "boo", "v0.3.0", "2.0.1"},
+			expectedHighestSupportedVersion: "1.2.3",
+			shouldFail:                      false,
+		},
+		{
+			versions:                        []string{},
+			expectedHighestSupportedVersion: "",
+			shouldFail:                      true,
+		},
+		{
+			versions:                        []string{"var", "boo", "foo"},
+			expectedHighestSupportedVersion: "",
+			shouldFail:                      true,
+		},
+	}
+
+	for _, tc := range testCases {
+		// Arrange & Act
+		actual, err := HighestSupportedVersion(tc.versions)
+
+		// Assert
+		if tc.shouldFail && err == nil {
+			t.Fatalf("expecting highestSupportedVersion to fail, but got nil error for testcase: %#v", tc)
+		}
+		if !tc.shouldFail && err != nil {
+			t.Fatalf("unexpected error during ValidatePlugin for testcase: %#v\r\n err:%v", tc, err)
+		}
+		if tc.expectedHighestSupportedVersion != "" {
+			result, err := actual.Compare(tc.expectedHighestSupportedVersion)
+			if err != nil {
+				t.Fatalf("comparison failed with %v for testcase %#v", err, tc)
+			}
+			if result != 0 {
+				t.Fatalf("expectedHighestSupportedVersion %v, but got %v for tc: %#v", tc.expectedHighestSupportedVersion, actual, tc)
+			}
+		}
+	}
+}