Finish setting up basic db migrations

apps/api/src/database/migrate.ts

@@ -0,0 +1,95 @@
+import * as path from 'path'
+import { promises as fs } from 'fs'
+import { FileMigrationProvider, Migrator, type MigrationResultSet } from 'kysely/migration'
+import { db } from './db'
+import { argv } from 'bun'
+import { env, log } from '../util'
+
+type HandlerResult = {
+    message: string;
+};
+
+function processResults(label: string, { error, results }: MigrationResultSet): string {
+    let message = "";
+
+    results?.forEach((it) => {
+        if (it.status === 'Success') {
+            message = `migration ${label} succeeded: "${it.migrationName}"`;
+        } else if (it.status === 'Error') {
+            throw new Error(`migration ${label} failed: "${it.migrationName}"`);
+        }
+    });
+
+    if (error) throw error;
+
+    return message;
+}
+
+const handlers: Record<string, (migrator: Migrator) => Promise<HandlerResult>> = {
+    "up": async function (migrator: Migrator) {
+        const resultSet = await migrator.migrateUp();
+        const message = processResults("up", resultSet);
+
+        return { message };
+    },
+    "down": async function (migrator: Migrator) {
+        const resultSet = await migrator.migrateDown();
+        const message = processResults("down", resultSet);
+
+        return { message };
+    },
+    "latest": async function (migrator: Migrator) {
+        const resultSet = await migrator.migrateToLatest();
+        const message = processResults("to latest", resultSet);
+
+        return { message };
+    },
+    "rollback": async function (migrator: Migrator) {
+        let count = 0;
+
+        while (true) {
+            const resultSet = await migrator.migrateDown();
+            if (!resultSet.results?.length) break;
+
+            processResults("rollback", resultSet);
+            ++count;
+        }
+
+        return { message: `rolled back ${count} migration(s)` };
+    }
+};
+
+// Main
+(async () => {
+    const command = argv[2] ?? "";
+    if (!handlers[command]) throw new Error("Unrecognized command");
+
+    const answer = prompt(`Run "${command}" migration against ${env.DATABASE_URL}? (y/N)`);
+    if (answer?.trim().toLowerCase() !== "y") {
+        log.info("Aborted");
+        await db.destroy();
+        return;
+    }
+
+    const migrator = new Migrator({
+        db,
+        provider: new FileMigrationProvider({
+            fs,
+            path,
+            // This needs to be an absolute path.
+            migrationFolder: path.join(__dirname, "migrations"),
+        }),
+    });
+
+    try {
+        const result = await handlers[command](migrator);
+        log.info({ name: command, result }, "finished");
+    }
+    catch (err) {
+        log.error({ name: command, err }, "failed");
+        process.exit(1)
+    }
+    finally {
+        await db.destroy()
+    }
+})();