/// The single process-wide Tokio runtime every generated test blocks on.
///
/// ~keep Every test used to be its own `#[tokio::test]`, which builds and drops a fresh
/// `current_thread` runtime per test. The extraction code under test reaches a crawler
/// whose HTTP client pool is a process-global cache keyed on config alone, with no runtime
/// identity. Hyper spawns a connection's driver task and the pool's idle reaper on whichever
/// runtime is current when the connection is created; when that runtime is dropped at the end
/// of the test, those tasks die but the now-dead connection stays in the global pool, ready
/// for a later test on a different runtime to check it out. That produced intermittent
/// "error sending request" and "error decoding response body" failures. Routing every test
/// through one shared runtime that lives for the whole process keeps every pooled connection's
/// driver task alive for as long as the pool can hand the connection out.
pub fn runtime() -> &'static tokio::runtime::Runtime {
static RUNTIME: OnceLock<tokio::runtime::Runtime> = OnceLock::new();
RUNTIME.get_or_init(|| {
// 16 MiB: tokio's ~2 MB default worker stack can overflow on a deep extraction
// future (a nested archive member, a multi-stage OCR pipeline), and a stack overflow
// aborts the process with SIGBUS instead of raising a catchable panic.
const TEST_RUNTIME_STACK_SIZE_BYTES: usize = 16 * 1024 * 1024;
tokio::runtime::Builder::new_multi_thread()
.enable_all()
.thread_stack_size(TEST_RUNTIME_STACK_SIZE_BYTES)
.build()
.expect("failed to build the shared test runtime")
})
}