Add database migrations

db/migrate.js

@@ -0,0 +1,42 @@
+// @ts-check
+
+const fs = require("fs")
+const {join} = require("path")
+
+async function migrate(db) {
+	let files = fs.readdirSync(join(__dirname, "migrations"))
+	files = files.sort()
+	db.prepare("CREATE TABLE IF NOT EXISTS migration (filename TEXT NOT NULL)").run()
+	let progress = db.prepare("SELECT * FROM migration").pluck().get()
+	if (!progress) {
+		progress = ""
+		db.prepare("INSERT INTO migration VALUES ('')").run()
+	}
+
+	let migrationRan = false
+
+	for (const filename of files) {
+		if (progress >= filename) continue
+		console.log(`Applying database migration ${filename}`)
+		if (filename.endsWith(".sql")) {
+			const sql = fs.readFileSync(join(__dirname, "migrations", filename), "utf8")
+			db.exec(sql)
+		} else if (filename.endsWith(".js")) {
+			await require("./" + join("migrations", filename))(db)
+		} else {
+			continue
+		}
+
+		migrationRan = true
+		db.transaction(() => {
+			db.prepare("DELETE FROM migration").run()
+			db.prepare("INSERT INTO migration VALUES (?)").run(filename)
+		})()
+	}
+
+	if (migrationRan) {
+		console.log("Database migrations all done.")
+	}
+}
+
+module.exports.migrate = migrate