create: allow specifying content directly

src/umzug.ts

@@ -346,6 +346,8 @@ export class Umzug<Ctx extends object = object> extends emittery<UmzugEvents<Ctx
 		allowExtension?: string;
 		allowConfusingOrdering?: boolean;
 		skipVerify?: boolean;
+		/** Optionally define the content for the new file. If not set, the configured template will be used. */
+		content?: string;
 	}): Promise<void> {
 		await this.runCommand('create', async ({ context }) => {
 			const isoDate = new Date().toISOString();
@@ -381,7 +383,10 @@ export class Umzug<Ctx extends object = object> extends emittery<UmzugEvents<Ctx
 				}
 			}
 
-			const template = this.options.create?.template ?? Umzug.defaultCreationTemplate;
+			const template =
+				typeof options.content === 'string'
+					? async () => [[filepath, options.content] as [string, string]]
+					: this.options.create?.template ?? Umzug.defaultCreationTemplate;
 
 			const toWrite = await template(filepath);
 			if (toWrite.length === 0) {

test/umzug.test.ts

@@ -172,6 +172,26 @@ describe('custom context', () => {
 		expect(pending[0]).toContain('test.x.js');
 	});
 
+	test(`create with custom content`, async () => {
+		const syncer = fsSyncer(path.join(__dirname, 'generated/create-custom-content'), {});
+		syncer.sync();
+
+		const umzug = new Umzug({
+			logger: undefined,
+			migrations: {
+				glob: ['*.js', { cwd: syncer.baseDir }],
+			},
+			create: {
+				folder: syncer.baseDir,
+			},
+		});
+
+		await umzug.create({ name: 'abc.js', content: 'exports.up = () => 123' });
+		const pending = names(await umzug.pending());
+		expect(pending).toHaveLength(1);
+		expect(syncer.read()[pending[0]]).toEqual('exports.up = () => 123');
+	});
+
 	test(`create with custom template async method`, async () => {
 		const syncer = fsSyncer(path.join(__dirname, 'generated/create-custom-template-async'), {});
 		syncer.sync();