gecko-dev/storage/test/unit/test_connection_interrupt.js

/* Any copyright is dedicated to the Public Domain.
 * http://creativecommons.org/publicdomain/zero/1.0/ */

// This file tests the functionality of mozIStorageAsyncConnection::interrupt.

add_task(async function test_sync_conn() {
  // Interrupt can only be used on async connections.
  let db = getOpenedDatabase();
  Assert.throws(() => db.interrupt(),
                /NS_ERROR_ILLEGAL_VALUE/,
                "interrupt() should throw if invoked on a synchronous connection");
  db.close();
});

add_task(async function test_wr_async_conn() {
  // Interrupt cannot be used on R/W async connections.
  let db = await openAsyncDatabase(getTestDB());
  Assert.throws(() => db.interrupt(),
                /NS_ERROR_ILLEGAL_VALUE/,
                "interrupt() should throw if invoked on a R/W connection");
  await asyncClose(db);
});

add_task(async function test_closed_conn() {
  let db = await openAsyncDatabase(getTestDB(), {readOnly: true});
  await asyncClose(db);
  Assert.throws(() => db.interrupt(),
                /NS_ERROR_NOT_INITIALIZED/,
                "interrupt() should throw if invoked on a closed connection");
});

add_task({
  // We use a timeout in the test that may be insufficient on Android emulators.
  // We don't really need the Android coverage, so skip on Android.
  skip_if: () => AppConstants.platform == "android",
}, async function test_async_conn() {
  let db = await openAsyncDatabase(getTestDB(), {readOnly: true});
  // This query is built to hang forever.
  let stmt = db.createAsyncStatement(`
    WITH RECURSIVE test(n) AS (
      VALUES(1)
      UNION ALL
      SELECT n + 1 FROM test
    )
    SELECT t.n
    FROM test,test AS t`);

  let completePromise = new Promise((resolve, reject) => {
    let listener = {
      handleResult(aResultSet) {
        reject();
      },
      handleError(aError) {
        reject();
      },
      handleCompletion(aReason) {
        resolve(aReason);
      },
    };
    stmt.executeAsync(listener);
    stmt.finalize();
  });

  // Wait for the statement to be executing.
  // This is not rock-solid, see the discussion in bug 1320301. A better
  // approach will be evaluated in a separate bug.
  await new Promise(resolve => do_timeout(500, resolve));

  db.interrupt();

  Assert.equal(await completePromise,
               Ci.mozIStorageStatementCallback.REASON_CANCELED,
               "Should have been canceled");

  await asyncClose(db);
});