Use async writeFile function in test instead of writeFileSync

Author: wan-hellopupil

test/index.js

@@ -275,25 +275,26 @@ describe('.replacePaths', () => {
 });
 
 describe('.refresh', () => {
-    it('should empty the cache of file hashes after a refresh()', () => {
-        fs.writeFileSync(path.join(__dirname, 'variable_file.txt'), 'File Content 1');
-
-        const staticifyObj = staticify(ROOT);
-
-        const versionedPath = staticifyObj.getVersionedPath('/test/variable_file.txt');
+    it('should empty the cache of file hashes after a refresh()', done => {
+        fs.writeFile(path.join(__dirname, 'variable_file.txt'), 'File Content 1', () => {
+            const staticifyObj = staticify(ROOT);
 
-        const versioned = versionedPath.split('.');
-        versioned.should.have.a.lengthOf(3);
-        versioned[0].should.equal('/test/variable_file');
-        versioned[2].should.equal('txt');
+            const versionedPath = staticifyObj.getVersionedPath('/test/variable_file.txt');
 
-        staticifyObj.refresh();
+            const versioned = versionedPath.split('.');
+            versioned.should.have.a.lengthOf(3);
+            versioned[0].should.equal('/test/variable_file');
+            versioned[2].should.equal('txt');
 
-        fs.writeFileSync(path.join(__dirname, 'variable_file.txt'), 'File Content 2');
+            staticifyObj.refresh();
 
-        const versionedPath2 = staticifyObj.getVersionedPath('/test/variable_file.txt');
+            fs.writeFile(path.join(__dirname, 'variable_file.txt'), 'File Content 2', () => {
+                const versionedPath2 = staticifyObj.getVersionedPath('/test/variable_file.txt');
 
-        versionedPath2.should.have.a.lengthOf(31);
-        versionedPath2.should.not.equal(versionedPath);
+                versionedPath2.should.have.a.lengthOf(31);
+                versionedPath2.should.not.equal(versionedPath);
+                done();
+            });
+        });
     });
 });