Support date without time

Start by reproducing the failure with the Todo.swift model and CreateTodo migration using a SQLite database and an ISO8601 date. Trace the SQLite date decoding path from the failing retrieval; done means fetching the todos succeeds and the Date field decodes without the reported error.

Vapor 4 cannot decode dates.

Steps to reproduce

1. Create an empty project using vapor-beta toolbox and using a SQLite database for testing purposes.

2. Open Todo.swift file and add a field to store a date

Todo model file looks:

import Fluent
import Vapor

final class Todo: Model, Content {
    static let schema = "todos"
    
    @ID(key: .id)
    var id: UUID?

    @Field(key: "title")
    var title: String
    
    @Field(key: "date")
    var date: Date

    init() { }

    init(id: UUID? = nil, title: String, date: Date) {
        self.id = id
        self.title = title
        self.date = date
    }
}

3. Configure the field on the migration file.

import Fluent

struct CreateTodo: Migration {
    func prepare(on database: Database) -> EventLoopFuture<Void> {
        return database.schema("todos")
            .id()
            .field("title", .string, .required)
            .field("date", .date, .required)
            .create()
    }

    func revert(on database: Database) -> EventLoopFuture<Void> {
        return database.schema("todos").delete()
    }
}

4. Run the migrations.

5. Create a new Todo with ISO8601 date.

6. Try to get the todos. It fails.

Expected behavior

The list of todos is returned.

Actual behavior

[ ERROR ] invalid field: date type: Date error: Decoding error: Value of type 'Date' required for key ''.

Environment

• Vapor Framework version: 4.0.0-rc.3.12
• Fluent Framework version: 4.0.0-rc.1
• Fluent-kit Framework version: 4.0.0-rc.1.16
• Fluent-sqlite-driver Framework version: 4.0.0-rc.1.1
• OS version: macOS 10.15.4