Support int8 migration versions via new int8-versions feature

This addresses, though does not really *fix* #83, because it doesn't make refinery support timestamped migrations *by default*, but only if you opt-in to the new feature.
However, making it an optional feature neatly sidesteps the unanswered questions in the issue, and so makes the implementation easier to complete and land.

Author: mpalmer

README.md

@@ -53,15 +53,17 @@ fn main() {
 For more library examples, refer to the [`examples`](https://github.com/rust-db/refinery/tree/main/examples).
 ### Example: CLI
 
-NOTE: 
+NOTE:
 
-- Contiguous (adjacent) migration version numbers are restricted to `u32` (unsigned, 32-bit integers).
-- Non-contiguous (not adjacent) migration version numbers are restricted to `u32` (unsigned, 32-bit integers).
+- By default, migration version numbers are restricted to `i32` (signed, 32-bit integers).
+- If you enable the `int8-versions` feature, this restriction is lifted to being able to use `i64`s for your migration version numbers (yay timestamps!).
+  Bear in mind that this feature must be enabled *before* you start using refinery on a given database.
+  Migrating an existing database's `refinery_schema_history` table to use `int8` versions will break the checksums on all previously-applied migrations, which is... bad.
 
 ```bash
 export DATABASE_URL="postgres://postgres:secret@localhost:5432/your-db"
 pushd migrations
-    # Runs ./src/V1__*.rs or ./src/V1__*.sql 
+    # Runs ./src/V1__*.rs or ./src/V1__*.sql
     refinery migrate -e DATABASE_URL -p ./src -t 1
 popd
 ```

refinery/Cargo.toml

@@ -25,6 +25,7 @@ tiberius-config = ["refinery-core/tiberius", "refinery-core/tiberius-config"]
 serde = ["refinery-core/serde"]
 toml = ["refinery-core/toml"]
 enums = ["refinery-macros/enums"]
+int8-versions = ["refinery-core/int8-versions"]
 
 [dependencies]
 refinery-core = { version = "0.8.14", path = "../refinery_core" }

refinery/src/lib.rs

@@ -32,7 +32,7 @@ for more examples refer to the [examples](https://github.com/rust-db/refinery/tr
 */
 
 pub use refinery_core::config;
-pub use refinery_core::{error, load_sql_migrations, Error, Migration, Report, Runner, Target};
+pub use refinery_core::{error, load_sql_migrations, Error, Migration, Report, Runner, SchemaVersion, Target};
 #[doc(hidden)]
 pub use refinery_core::{AsyncMigrate, Migrate};
 pub use refinery_macros::embed_migrations;

refinery/tests/migrations_int8/U20240504090241__initial.rs

@@ -0,0 +1,15 @@
+use barrel::{types, Migration};
+
+use crate::Sql;
+
+pub fn migration() -> String {
+    let mut m = Migration::new();
+
+    m.create_table("persons", |t| {
+        t.add_column("id", types::primary());
+        t.add_column("name", types::varchar(255));
+        t.add_column("city", types::varchar(255));
+    });
+
+    m.make::<Sql>()
+}

refinery/tests/migrations_int8/U20240504090301__add_cars_and_motos_table.sql

@@ -0,0 +1,8 @@
+CREATE TABLE cars (
+    id int,
+    name varchar(255)
+);
+CREATE TABLE motos (
+    id int,
+    name varchar(255)
+);

refinery/tests/migrations_int8/U20240504090322__add_brand_to_cars_table.sql

@@ -0,0 +1,2 @@
+ALTER TABLE cars
+ADD brand varchar(255);

refinery/tests/migrations_int8/U20240504090343__add_year_to_motos_table.rs

@@ -0,0 +1,13 @@
+use barrel::{types, Migration};
+
+use crate::Sql;
+
+pub fn migration() -> String {
+    let mut m = Migration::new();
+
+    m.change_table("motos", |t| {
+        t.add_column("brand", types::varchar(255).nullable(true));
+    });
+
+    m.make::<Sql>()
+}

refinery/tests/postgres.rs

@@ -31,6 +31,16 @@ mod postgres {
         embed_migrations!("./tests/migrations_missing");
     }
 
+    #[cfg(feature = "int8-versions")]
+    mod int8 {
+        use refinery::embed_migrations;
+        embed_migrations!("./tests/migrations_int8");
+    }
+
+    fn db_uri() -> String {
+        std::env::var("DB_URI").unwrap_or("postgres://postgres@localhost:5432/postgres".to_string())
+    }
+
     fn get_migrations() -> Vec<Migration> {
         embed_migrations!("./tests/migrations");
 
@@ -189,6 +199,37 @@ mod postgres {
         });
     }
 
+    #[test]
+    #[cfg(feature = "int8-versions")]
+    fn applies_migration_int8() {
+        run_test(|| {
+            let mut client = Client::connect(&db_uri(), NoTls).unwrap();
+            let report = int8::migrations::runner().run(&mut client).unwrap();
+
+            let applied_migrations = report.applied_migrations();
+
+            assert_eq!(4, applied_migrations.len());
+
+            assert_eq!(20240504090241, applied_migrations[0].version());
+            assert_eq!(20240504090301, applied_migrations[1].version());
+            assert_eq!(20240504090322, applied_migrations[2].version());
+            assert_eq!(20240504090343, applied_migrations[3].version());
+
+            client
+                .execute(
+                    "INSERT INTO persons (name, city) VALUES ($1, $2)",
+                    &[&"John Legend", &"New York"],
+                )
+                .unwrap();
+            for row in &client.query("SELECT name, city FROM persons", &[]).unwrap() {
+                let name: String = row.get(0);
+                let city: String = row.get(1);
+                assert_eq!("John Legend", name);
+                assert_eq!("New York", city);
+            }
+        });
+    }
+
     #[test]
     fn applies_migration_grouped_transaction() {
         run_test(|| {
@@ -292,8 +333,15 @@ mod postgres {
             assert_eq!("initial", migrations[0].name());
             assert_eq!("add_cars_table", applied_migrations[1].name());
 
+            #[cfg(not(feature = "int8-versions"))]
             assert_eq!(2959965718684201605, applied_migrations[0].checksum());
+            #[cfg(feature = "int8-versions")]
+            assert_eq!(13938959368620441626, applied_migrations[0].checksum());
+
+            #[cfg(not(feature = "int8-versions"))]
             assert_eq!(8238603820526370208, applied_migrations[1].checksum());
+            #[cfg(feature = "int8-versions")]
+            assert_eq!(5394706226941044339, applied_migrations[1].checksum());
         });
     }
 

refinery_cli/Cargo.toml

@@ -21,6 +21,7 @@ mysql = ["refinery-core/mysql"]
 sqlite = ["refinery-core/rusqlite"]
 sqlite-bundled = ["sqlite", "refinery-core/rusqlite-bundled"]
 mssql = ["refinery-core/tiberius-config", "tokio"]
+int8-versions = ["refinery-core/int8-versions"]
 
 [dependencies]
 refinery-core = { version = "0.8.14", path = "../refinery_core", default-features = false, features = ["toml"]  }

refinery_cli/src/cli.rs

@@ -4,6 +4,8 @@ use std::path::PathBuf;
 
 use clap::{Args, Parser};
 
+use refinery_core::SchemaVersion;
+
 #[derive(Parser)]
 #[clap(version)]
 pub enum Cli {
@@ -38,7 +40,7 @@ pub struct MigrateArgs {
 
     /// Migrate to the specified target version
     #[clap(short)]
-    pub target: Option<u32>,
+    pub target: Option<SchemaVersion>,
 
     /// Set migration table name
     #[clap(long, default_value = "refinery_schema_history")]