VFS raises error when requested to delete a non-existing file

[rherrmann]

In an attempt to test the behaviour of an SQL statement when run in parallel, I tried to execute the statement from multiple workers.

Here is a striped-down version of the code:

// main.ts
import { DB } from "https://deno.land/x/[email protected]/mod.ts";

const filename = "test.sqlite";
const db = new DB(filename);
db.execute("drop table if exists t; create table t (c text);");
const workers: Worker[] = [];
const workerPromises: Promise<void>[] = [];
for (let index = 0; index < 10; index++) {
  const worker = new Worker(
    new URL("./worker.ts", import.meta.url).href,
    { name: "worker " + index, type: "module" },
  );
  const deferred = Promise.withResolvers<void>();
  worker.onmessage = () => deferred.resolve();
  worker.onmessageerror = () => deferred.reject();
  workers.push(worker);
  workerPromises.push(deferred.promise);
}
workers.forEach((worker) => worker.postMessage({ filename }));
await Promise.all(workerPromises);
db.queryEntries("select * from t").forEach((row) => console.log(row));
db.close();

// worker.ts
/// <reference lib="webworker" />
import { DB } from "https://deno.land/x/[email protected]/mod.ts";

self.onmessage = (event) => {
  const { filename } = event.data;
  const db = new DB(filename, { mode: "write" });
  db.query("insert into t (c) values (:c)", { c: "inserted by " + self.name });
  db.close();
  self.postMessage({ done: true });
  self.close();
};

When the VFS is asked to delete a journal file, it raises this error:

error: Uncaught (in worker "worker 1") NotFound: No such file or directory (os error 2): remove 'test.sqlite-journal'
      Deno.removeSync(path);
           ^
    at Object.removeSync (ext:deno_fs/30_fs.js:209:7)
    at js_delete (https://deno.land/x/[email protected]/build/vfs.js:39:12)
    at <anonymous> (wasm://wasm/0028679a:1:5597)
    ...
error: Uncaught (in promise) Error: Unhandled error in child worker.
    at Worker.#pollControl (ext:runtime/11_workers.js:164:19)
    at eventLoopTick (ext:core/01_core.js:182:7)

After reading #240 and #249 I'm uncertain if the code should get thus far. However, the SQLite demo VFS seems to silently ignore request to delete a non-existing file and returns SQLITE_OK (search for demoDelete).