claircore: add FromSemver

Signed-off-by: RTann <[email protected]>

version.go

@@ -4,6 +4,8 @@ import (
 	"bytes"
 	"strconv"
 	"strings"
+
+	"github.com/Masterminds/semver"
 )
 
 // Version describes a revision of some sort that is ordered correctly within
@@ -21,6 +23,16 @@ func VersionSort(vs []Version) func(int, int) bool {
 	return func(i, j int) bool { return vs[i].Compare(&vs[j]) == -1 }
 }
 
+// FromSemver is the SemVer to claircore.Version mapping used by this package.
+func FromSemver(v *semver.Version) (out Version) {
+	out.Kind = `semver`
+	// Leave a leading epoch, for good measure.
+	out.V[1] = int32(v.Major())
+	out.V[2] = int32(v.Minor())
+	out.V[3] = int32(v.Patch())
+	return out
+}
+
 // MarshalText implments encoding.TextMarshaler.
 func (v *Version) MarshalText() ([]byte, error) {
 	if v.Kind == "" {

version_test.go

@@ -3,6 +3,7 @@ package claircore
 import (
 	"testing"
 
+	"github.com/Masterminds/semver"
 	"github.com/google/go-cmp/cmp"
 )
 
@@ -98,3 +99,37 @@ func TestVersionMarshal(t *testing.T) {
 		t.Run(tc.Name, tc.MarshalTest)
 	}
 }
+
+func TestFromSemver(t *testing.T) {
+	testcases := []struct {
+		name   string
+		semver *semver.Version
+		want   Version
+	}{
+		{
+			name:   "0.3.0",
+			semver: semver.MustParse("0.3.0"),
+			want: Version{
+				Kind: `semver`,
+				V:    [...]int32{0, 0, 3, 0, 0, 0, 0, 0, 0, 0},
+			},
+		},
+		{
+			name:   "1.1.6",
+			semver: semver.MustParse("1.1.6"),
+			want: Version{
+				Kind: `semver`,
+				V:    [...]int32{0, 1, 1, 6, 0, 0, 0, 0, 0, 0},
+			},
+		},
+	}
+
+	for _, tt := range testcases {
+		t.Run(tt.name, func(t *testing.T) {
+			got := FromSemver(tt.semver)
+			if !cmp.Equal(tt.want, got) {
+				t.Error(cmp.Diff(tt.want, got))
+			}
+		})
+	}
+}