I'm testing a method that inserts a new user into a Postgres DB:
internal static func insert(new user: Endpoint.Signup.User) throws {
let timestamp: Date = .init()
let salt: UUID = .init()
let hashedPassword: Array<UInt8>=try PKCS5.PBKDF2(
password: user.password.bytes, salt: salt.bytes, iterations: 4096,
keyLength: 32, variant: .sha2(.sha256)
).calculate()
let verificationId: UUID = .init()
let connection=try API.shared.pools.requestConnection().wait()
defer {
API.shared.pools.releaseConnection(connection)
}
do {
let _=try connection.simpleQuery("BEGIN").wait()
let _=try connection.everyUserInsert(user.id, email: user.email, username: user.username, timestamp, .beginningEmailUser).wait()
let _=try connection.populatedUserInsert(user.id, user, timestamp).forEach({ let _=try $0.wait() })
let _=try connection.beginningEmailUserInsert(id: user.id, hashedPassword, salt: salt, verificationId: verificationId).wait()
let _=try connection.simpleQuery("COMMIT").wait()
} catch {
// if `ROLLBACK` also fails, log both errors
do {
let _=try connection.simpleQuery("ROLLBACK").wait()
} catch let rollbackError {
throw LoggedError(statusCode: .internalServerError, displayedMessage: "Server error", loggedMessage: """
Transaction Error: \(error)
Rollback Error: \(rollbackError)
"""
)
}
throw error
}
}
This method operates as expected.
Then in the test method — after the above method returns — I run another query to ensure the insertion was successful:
// ensure user is there
let db=API.shared.pools.database(logger: .init(label: "APITests"))
var select: String="SELECT from \(BeginningEmailUser.tableName) WHERE \(BeginningEmailUser.Column.id)=$1"
var rows=try db.query(select, [.init(uuid: user.id)]).wait()
XCTAssert(rows.count == 1, "Unexpected insertion result")
This also runs successfully.
The problem occurs when I uncomment the next line that's meant to delete the test user:
// clean up
let _=try db.query("DELETE from \(BeginningEmailUser.tableName) WHERE \(BeginningEmailUser.Column.id)=$1", [.init(uuid: user.id)]).wait()
That's when I experience the precondition failure:
"How can an error occur if the connection is already closed?"
This is issued from PostgresNIO.ConnectionStateMachine.closeAndCleanup(_:). Does anyone see any obvious issue with what I'm doing here that could forgo me having to put together a minimal reproducible example? If not, please share and I'll put one together.