squill/
db.rs

1use std::collections::BTreeMap;
2
3use sqlx::postgres::PgConnection;
4
5use crate::MigrationId;
6
7#[derive(Debug, Clone, PartialEq, Eq)]
8pub struct MigrationRecord {
9    pub id: MigrationId,
10    pub name: String,
11    pub run_at: time::PrimitiveDateTime,
12}
13
14#[derive(Debug, Clone, PartialEq, Eq)]
15pub struct MigrationLog {
16    pub(crate) log: BTreeMap<MigrationId, MigrationRecord>,
17}
18
19impl MigrationLog {
20    pub async fn new(conn: &mut PgConnection) -> Result<Self, QueryError> {
21        let applied = applied_migrations(conn).await?;
22
23        let index = applied
24            .into_iter()
25            .map(|row| {
26                (
27                    MigrationId(row.id),
28                    MigrationRecord {
29                        id: MigrationId(row.id),
30                        name: row.name,
31                        run_at: row.run_at,
32                    },
33                )
34            })
35            .collect();
36
37        Ok(Self { log: index })
38    }
39
40    pub fn iter(&self) -> impl Iterator<Item = &MigrationRecord> {
41        self.log.values()
42    }
43
44    pub fn last(&self) -> Option<MigrationRecord> {
45        self.iter().cloned().max_by_key(|row| (row.run_at, row.id))
46    }
47}
48
49#[derive(sqlx::FromRow, Debug, Clone, PartialEq, Eq)]
50struct MigrationRow {
51    pub id: i64,
52    pub name: String,
53    pub run_at: time::PrimitiveDateTime,
54}
55
56async fn applied_migrations(conn: &mut PgConnection) -> Result<Vec<MigrationRow>, QueryError> {
57    let query = sqlx::query_as("select * from schema_migrations order by id asc");
58    match query.fetch_all(conn).await {
59        Ok(res) => Ok(res),
60        Err(err) => {
61            if let sqlx::Error::Database(ref db_err) = err {
62                if let Some(code) = db_err.code() {
63                    // undefined_table
64                    if code == "42P01" {
65                        // The expected table doesn't exist. This is probably because we haven't
66                        // run the first migration that will create this table.
67                        return Ok(Vec::new());
68                    }
69                }
70            }
71            Err(QueryError(err))
72        }
73    }
74}
75
76#[derive(thiserror::Error, Debug)]
77#[error("failed to query applied migrations: {0}")]
78pub struct QueryError(sqlx::Error);
79
80#[cfg(test)]
81mod tests {
82    use sqlx::Executor;
83
84    use crate::testing::*;
85    use crate::MigrationIndex;
86
87    use super::*;
88
89    #[tokio::test]
90    async fn missing_table() {
91        let env = TestEnv::new().await.unwrap();
92
93        let config = env.config();
94        let mut conn = config.connect().await.unwrap();
95
96        conn.execute("drop table if exists schema_migrations")
97            .await
98            .unwrap();
99
100        let log = MigrationLog::new(&mut conn).await.unwrap();
101        assert!(log.log.is_empty(), "{:?}", log);
102    }
103
104    #[tokio::test]
105    async fn last_applied_uninit() {
106        let env = TestEnv::new().await.unwrap();
107
108        let config = env.config();
109        let mut conn = config.connect().await.unwrap();
110
111        let last = MigrationLog::new(&mut conn).await.unwrap().last();
112        assert_eq!(None, last);
113    }
114
115    #[tokio::test]
116    async fn last_applied_init() {
117        let env = TestEnv::initialized().await.unwrap();
118
119        let config = env.config();
120        let mut conn = config.connect().await.unwrap();
121
122        let last = MigrationLog::new(&mut conn).await.unwrap().last();
123        assert!(last.is_some());
124
125        let last = last.unwrap();
126        assert_eq!(MigrationId(0), last.id);
127        assert_eq!("init", &last.name);
128    }
129
130    #[tokio::test]
131    async fn last_applied_out_of_order() {
132        let env = TestEnv::initialized().await.unwrap();
133        let config = env.config();
134
135        let mut index = MigrationIndex::new(&config.migrations_dir).unwrap();
136
137        let one = index.create(fake_migration(1, "one")).unwrap();
138        let two = index.create(fake_migration(2, "two")).unwrap();
139        let _ = index.create(fake_migration(3, "three")).unwrap();
140
141        // Apply "2-two" _before_ "1-one".
142        let mut conn = config.connect().await.unwrap();
143        two.up(&mut conn).await.unwrap();
144        one.up(&mut conn).await.unwrap();
145
146        let last = MigrationLog::new(&mut conn).await.unwrap().last();
147        assert!(last.is_some());
148
149        let last = last.unwrap();
150        assert_eq!(MigrationId(1), last.id);
151        assert_eq!("one", &last.name);
152    }
153}
squill/db.rs

squill/
db.rs
