transact-rs/sqlx · error

failed to apply test fixture

Error message

failed to apply test fixture {:?}: {:?}

What it means

sqlx-core's testing scaffold (setup_test_db, used by #[sqlx::test]) panics when executing a fixture SQL file against the freshly created test database fails. The panic wraps the sqlx error from `conn.execute(fixture.contents)`, printing the fixture path and the underlying DB error, so the real cause (bad SQL, dependency order, missing schema) is in the attached error value.

Solutions

1. Read the wrapped error in the panic message — it names the exact SQL error (relation does not exist, constraint violation, syntax).
2. Ensure all prerequisite fixtures are listed, dependencies first: `fixtures(path("schema.sql"), path("users.sql"))`.
3. Run migrations before fixtures (the test scaffold applies migrations if configured; otherwise execute them in a setup step).
4. Validate the fixture SQL directly: pipe it into a fresh `psql`/`mysql`/`sqlite3` empty database to reproduce outside of tests.
5. Make fixtures idempotent and self-contained (CREATE TABLE IF NOT EXISTS / ON CONFLICT DO NOTHING).

Example fix

// before
#[sqlx::test(fixtures(path("orders.sql")))]
async fn test_orders(pool: PgPool) { /* orders.sql references users table */ }

// after
#[sqlx::test(fixtures(path("schema.sql"), path("users.sql"), path("orders.sql")))]
async fn test_orders(pool: PgPool) { /* prerequisites loaded first */ }

// Validate fixture SQL against a scratch DB before running tests:
// psql "postgres://localhost/scratch" -v ON_ERROR_STOP=1 -f tests/fixtures/orders.sql
// Also list fixtures in dependency order:
// #[sqlx::test(fixtures(path("schema.sql"), path("users.sql"), path("orders.sql")))]

// The panic already embeds the underlying error; parse it in test output:
// failed to apply test fixture "tests/fixtures/orders.sql": <sqlx error> —
// read the wrapped sqlx::Error to find the failing SQL statement.

When it happens

Trigger: `#[sqlx::test(fixtures(path("users.sql")))]` where users.sql contains SQL that errors on the empty test database: referencing a table created by another fixture that isn't listed, syntax errors, DB-specific SQL, INSERTs violating constraints, or fixtures executed in the wrong order.

Common situations: Fixture files that worked locally against a manually-seeded dev DB but assume objects a clean test DB lacks; fixture ordering issues (fixtures run in listed order but dependencies not listed first); migrations not applied before fixtures in the test setup.

Related errors

• cleanup_test() invoked outside `#[sqlx::test]`
• cleanup_test() invoked outside `#[sqlx::test]`
• DATABASE_URL must be set
• DATABASE_URL must be set
• failed to apply migrations

AI-assisted analysis of transact-rs/sqlx@03af8bcc57 (2026-09-03). Data as JSON: /api/errors/6e2122ff1ba4ec7b. Report an issue: GitHub.

Appendix: source

Thrown at sqlx-core/src/testing/mod.rs:269

    for<'c> &'c mut DB::Connection: Executor<'c, Database = DB>,
{
    let mut conn = copts
        .connect()
        .await
        .expect("failed to connect to test database");

    if let Some(migrator) = args.migrator {
        migrator
            .run_direct(None, &mut conn, false)
            .await
            .expect("failed to apply migrations");
    }

    for fixture in args.fixtures {
        (&mut conn)
            .execute(fixture.contents)
            .await
            .unwrap_or_else(|e| panic!("failed to apply test fixture {:?}: {:?}", fixture.path, e));
    }

    conn.close()
        .await
        .expect("failed to close setup connection");
}

View on GitHub (pinned to 03af8bcc57)