refactor(version): unify version tag detection across packages (gq)

2 files changed, 48 insertions, 0 deletions

diff --git a/internal/version/version_tag.go b/internal/version/version_tag.go
new file mode 100644
index 0000000..0d12ffa
--- /dev/null
+++ b/internal/version/version_tag.go
@@ -0,0 +1,11 @@
+package version
+
+import "regexp"
+
+var versionTagPattern = regexp.MustCompile(`^v?\d+(\.\d+)?(\.\d+)?$`)
+
+// IsVersionTag checks if a tag name is a version tag.
+// Supported formats: vX.Y.Z, vX.Y, vX, X.Y.Z, X.Y, X.
+func IsVersionTag(tag string) bool {
+	return versionTagPattern.MatchString(tag)
+}
diff --git a/internal/version/version_tag_test.go b/internal/version/version_tag_test.go
new file mode 100644
index 0000000..93ee3b8
--- /dev/null
+++ b/internal/version/version_tag_test.go
@@ -0,0 +1,37 @@
+package version
+
+import "testing"
+
+func TestIsVersionTag(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		tag  string
+		want bool
+	}{
+		{name: "single digit", tag: "1", want: true},
+		{name: "single digit with v prefix", tag: "v1", want: true},
+		{name: "major minor", tag: "1.2", want: true},
+		{name: "major minor with v prefix", tag: "v1.2", want: true},
+		{name: "major minor patch", tag: "1.2.3", want: true},
+		{name: "major minor patch with v prefix", tag: "v1.2.3", want: true},
+		{name: "empty", tag: "", want: false},
+		{name: "letter prefix", tag: "release-1.2.3", want: false},
+		{name: "too many components", tag: "1.2.3.4", want: false},
+		{name: "trailing dot", tag: "1.", want: false},
+		{name: "prerelease style", tag: "1-beta", want: false},
+		{name: "prerelease style with v prefix", tag: "v1-beta", want: false},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			got := IsVersionTag(tc.tag)
+			if got != tc.want {
+				t.Fatalf("IsVersionTag(%q) = %v, want %v", tc.tag, got, tc.want)
+			}
+		})
+	}
+}