fix: restore ability to use lockfile() directly

Author: satazor

README.md

@@ -92,6 +92,8 @@ lockfile.lock('some/file')
     // which will also return a promise
     return release();
 });
+
+// Alternatively, you may use lockfile(`some/file`) directly.
 ```
 
 

index.js

@@ -31,6 +31,7 @@ function checkSync(file, options) {
     return toSync(lockfile.check)(file, toSyncOptions(options));
 }
 
+module.exports = lock;
 module.exports.lock = lock;
 module.exports.unlock = unlock;
 module.exports.lockSync = lockSync;

test/lock.test.js

@@ -23,6 +23,10 @@ afterEach(async () => {
     rimraf.sync(`${tmpDir}/*`);
 });
 
+it('should be the default export', () => {
+    expect(lockfile).toBe(lockfile.lock);
+});
+
 it('should fail if the file does not exist by default', async () => {
     expect.assertions(1);