[FIXED] In Node/sqlite3, does run's first callback parameter return Error?

Issue

I’m fairly certain I’m using relatively new versions of sqlite3 (5.0.11) and @types/sqlite3 (3.1.8) but the types are not matching the behavior.

Roughly, it seems as though despite @types/sqlite3/index.d.ts including this declaration:

run(sql: string, params: any, callback?: (this: RunResult, err: Error | null) => void): this;

err is the first parameter.

What’s going on here?

Details:

const db: sqlite3.Database;
this.db.run('DELETE from ... (actually it's invalid SQL)', (result: RunResult, err: Error) => {...});

This is what result contains:

Error: SQLITE_ERROR: no such table: ANY {errno: 1, code: 'SQLITE_ERROR', stack: 'Error: SQLITE_ERROR: no such table: ANY', message: 'SQLITE_ERROR: no such table: ANY'}
code: 'SQLITE_ERROR'
errno: 1
message: 'SQLITE_ERROR: no such table: ANY'
stack: 'Error: SQLITE_ERROR: no such table: ANY'

I don’t know how Error is really supposed to look, but this looks more like type Error than type RunResult.

This is how I invoke the database:

if (params !== undefined) {
  this.db.run(sql, params, cb);
} else {
  this.db.run(sql, cb);
}

And this is cb:

const cb = (result: RunResult, err: Error | null) => {
  if (err) {
    reject(err);
  } else {
    resolve(result);
  }
};

Am I doing something obviously wrong?

Solution

Declaring this in a function tells typescript the type of this in the function body, it does not get added to the function parameters.

function cb(this: RunResult, err: Error | null) {
  if (err) {
    reject(err);
  } else {
    resolve(this); // `this` will be the RunResult
  }
}

The above function is still a function will a single parameter err, we have just told typescript the type of this in the function body. This does not work for arrow functions

Answered By – Iain Shelvington

Answer Checked By – David Marino (Easybugfix Volunteer)

Leave a Reply

(*) Required, Your email will not be published