migrant_lib 0.34.0 

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48

use crate::{Config, DbKind, Direction};
use std::fmt;

pub trait MigratableClone {
    fn clone_migratable_box(&self) -> Box<dyn Migratable>;
}
impl<T> MigratableClone for T
where
    T: 'static + Migratable + Clone,
{
    fn clone_migratable_box(&self) -> Box<dyn Migratable> {
        Box::new(self.clone())
    }
}

/// A type that can be used to define database migrations
pub trait Migratable: MigratableClone {
    /// Define functionality that runs for `up` migrations
    fn apply_up(&self, _: DbKind, _: &Config) -> Result<(), Box<dyn (::std::error::Error)>> {
        print_flush!("(empty)");
        Ok(())
    }

    /// Define functionality that runs for `down` migrations
    fn apply_down(&self, _: DbKind, _: &Config) -> Result<(), Box<dyn (::std::error::Error)>> {
        print_flush!("(empty)");
        Ok(())
    }

    /// A unique identifying tag
    fn tag(&self) -> String;

    /// Option migration description. Defaults to `Migratable::tag`
    fn description(&self, _: &Direction) -> String {
        self.tag()
    }
}
impl Clone for Box<dyn Migratable> {
    fn clone(&self) -> Box<dyn Migratable> {
        self.clone_migratable_box()
    }
}

impl fmt::Debug for Box<dyn Migratable> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "Migration: {}", self.tag())
    }
}