test(drop): run past a small search budget instead of writing 50,001 files

internal/drop/drop.go

@@ -63,8 +63,10 @@ const maxUpload = 32 << 20
 
 // maxEntries bounds one searched tree, so a drop over a home directory or a
 // vendored monorepo cannot stall the window. Past it the search gives up and
-// the item falls through to the upload copy.
-const maxEntries = 50_000
+// the item falls through to the upload copy. Replaced in tests: proving the
+// budget runs out takes one more file than it, and 50,001 files cost close to
+// forty seconds a test on Windows.
+var maxEntries = 50_000
 
 // homeDir is os.UserHomeDir, replaced in tests: the search must never reach
 // the machine's real home, on any OS.

internal/drop/drop_test.go

@@ -35,6 +35,15 @@ func homeAt(t *testing.T, home string) *Service {
 	return New(t.TempDir(), nil)
 }
 
+// smallBudget shrinks the search budget for one test, so running past it takes
+// a handful of files rather than fifty thousand.
+func smallBudget(t *testing.T) {
+	t.Helper()
+	previous := maxEntries
+	maxEntries = 16
+	t.Cleanup(func() { maxEntries = previous })
+}
+
 // writeFile creates path with size bytes and a known modification time,
 // standing in for the file the user drags out of a file manager.
 func writeFile(t *testing.T, path string, size int, mtime time.Time) Item {
@@ -123,6 +132,7 @@ func TestResolveRefusesTwins(t *testing.T) {
 // is not a unique match, and answering with it hands the session the wrong file
 // — the exact failure the whole rule exists to prevent.
 func TestResolveRefusesTwinsSplitByTheBudget(t *testing.T) {
+	smallBudget(t)
 	root := t.TempDir()
 	mtime := time.Now().Add(-time.Hour).Truncate(time.Second)
 	item := writeFile(t, filepath.Join(root, "a", "app.ts"), 41, mtime)
@@ -221,6 +231,7 @@ func TestResolveMapsEveryItem(t *testing.T) {
 // reported the directory sitting right beside it as missing. The noise here is
 // one entry over the budget for exactly that reason.
 func TestResolveFindsShallowSiblingBeforeNoise(t *testing.T) {
+	smallBudget(t)
 	root := t.TempDir()
 	noise := filepath.Join(root, ".cache", "pkg")
 	if err := os.MkdirAll(noise, 0o755); err != nil {