fix(updater): skip target tests on windows

The new TestGetTargetInfoTable / TestDownloadTargetTable /
TestFindCachedTargetTable cases route through
simulator.RepositorySimulator.fetch, which keys off
filepath.Separator and the hardcoded "/targets/" prefix --
unreachable on windows where filepath.Separator is backslash.
The underlying production code still gets coverage from the
Linux and macOS runners.

Skip the three tests on runtime.GOOS == "windows" until the
simulator's target URL routing is fixed in a separate change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: Radoslav Dimitrov <radoslav@stacklok.com>

Author: rdimitrov

metadata/updater/updater_test.go

@@ -20,6 +20,7 @@ package updater
 import (
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 	"time"
 
@@ -30,6 +31,18 @@ import (
 	"github.com/theupdateframework/go-tuf/v2/metadata/config"
 )
 
+// skipIfWindows guards the target-download tables -- the simulator's URL
+// routing for target files uses filepath.Separator, which is "\" on
+// Windows; that combined with hardcoded "/targets/" prefix checks makes
+// the routing unreachable from these tests. The underlying code under
+// test still gets coverage from Linux and macOS runners.
+func skipIfWindows(t *testing.T) {
+	t.Helper()
+	if runtime.GOOS == "windows" {
+		t.Skip("simulator target URL routing is broken on windows; see metadata/updater/updater_test.go")
+	}
+}
+
 // createAndRefresh creates an updater for the test repository and runs Refresh
 func createAndRefresh(t *testing.T, repo *simulator.TestRepository) (*Updater, error) {
 	t.Helper()
@@ -1154,6 +1167,7 @@ func TestDelegatesConsistentSnapshotTable(t *testing.T) {
 // the implicit Refresh that GetTargetInfo triggers when targets isn't
 // trusted yet.
 func TestGetTargetInfoTable(t *testing.T) {
+	skipIfWindows(t)
 	const targetPath = "hello.txt"
 	targetContent := []byte("hello, table-driven world")
 
@@ -1201,6 +1215,7 @@ func TestGetTargetInfoTable(t *testing.T) {
 // happy path with the configured base URL, happy path with an explicit
 // targetBaseURL argument, and the rejection when neither is set.
 func TestDownloadTargetTable(t *testing.T) {
+	skipIfWindows(t)
 	// The simulator's URL routing for targets has multiple bugs that
 	// compound under consistent-snapshot mode -- a flat target path
 	// panics lastIndex, and a nested one collides with the hash-prefix
@@ -1291,6 +1306,7 @@ func TestDownloadTargetTable(t *testing.T) {
 // DownloadTarget call, after a hash-mismatching local file, and when the
 // local file is missing entirely.
 func TestFindCachedTargetTable(t *testing.T) {
+	skipIfWindows(t)
 	// As in TestDownloadTargetTable, use a doubly-nested path so the
 	// simulator's URL parser doesn't trip on shallow names.
 	const targetPath = "a/b/cached.txt"