func Compare(x, y string) int { return compare(stripGo(x), stripGo(y)) }

// IsValid reports whether the version x is valid.
func IsValid(x string) bool { return isValid(stripGo(x)) }

// stripGo converts from a "go1.21" version to a "1.21" version.
// If v does not start with "go", stripGo returns the empty string (a known invalid version).
func stripGo(v string) string {
	v, _, _ = strings.Cut(v, "-") // strip -bigcorp suffix.

apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: invalid-filter-wrong-field
spec:
  rules:
  - filters:
    - type: RequestHeaderModifier
      requestRedirect: 

apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: invalid-filter-duplicate-header
spec:
  rules:
  - filters:
    - type: RequestHeaderModifier
      requestHeaderModifier:
        remove:
        - foo

	// a valid type.
	if x.typ == nil {
		x.typ = Typ[Invalid]
	}

	check.index(index, length)
	return false
}

func (check *Checker) sliceExpr(x *operand, e *ast.SliceExpr) {
	check.expr(nil, x, e.X)
	if x.mode == invalid {
		check.use(e.Low, e.High, e.Max)
		return
	}

	valid := false
	length := int64(-1) // valid if >= 0
	switch u := coreString(x.typ).(type) {
	case nil:

		},
		{
			name:          "invalid: client version is empty",
			remoteVersion: "v1.12.1",
			clientVersion: "",
			expectedError: true,
		},
		{
			name:          "invalid: error parsing the remote version",
			remoteVersion: "invalid-version",
			clientVersion: "v1.12.0",
			expectedError: true,
		},
		{
			name:          "invalid: error parsing the client version",

apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: invalid-path-alphanum-specialchars-mix
spec:
  rules:
  - matches:
    - path:
        type: PathPrefix

	if !valid {
		check.errorf(e.Pos(), NonSliceableOperand, invalidOp+"cannot index %s", x)
		check.use(e.Index)
		x.mode = invalid
		return false
	}

	index := check.singleIndex(e)
	if index == nil {
		x.mode = invalid
		return false
	}

	// In pathological (invalid) cases (e.g.: type T1 [][[]T1{}[0][0]]T0)
	// the element type may be accessed before it's set. Make sure we have
	// a valid type.

Pengyuan Bian <******@****.***> 1625172474 -0700

		},
		"invalid local volume no node affinity": {
			isExpectedFailure: true,
			volume: testVolume("invalid-local-volume-no-node-affinity", "",
				testLocalVolume("/foo", nil)),
		},
		"invalid local volume empty path": {
			isExpectedFailure: true,
			volume: testVolume("invalid-local-volume-empty-path", "",
				testLocalVolume("", simpleVolumeNodeAffinity("foo", "bar"))),
		},
		"invalid-local-volume-backsteps": {

// contain release numbers ("go1.20.1" is not a valid goVersion).
type goVersion string

// asGoVersion returns v as a goVersion (e.g., "go1.20.1" becomes "go1.20").
// If v is not a valid Go version, the result is the empty string.
func asGoVersion(v string) goVersion {
	return goVersion(version.Lang(v))
}

// isValid reports whether v is a valid Go version.
func (v goVersion) isValid() bool {
	return v != ""
}