test: refactor test-fs-fsync

- replace var with const. - remove successes var. - use assert.ifError() for handling all errors. - wrap all callbacks with common.mustCall(). PR-URL: #10176 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Santiago Gimeno <[email protected]> Reviewed-By: Italo A. Casas <[email protected]> Reviewed-By: Sakthipriyan Vairamani <[email protected]>

Author: radelmann

test/parallel/test-fs-fsync.js

@@ -1,32 +1,23 @@
 'use strict';
-varcommon=require('../common');
-varassert=require('assert');
+constcommon=require('../common');
+constassert=require('assert');
 
-varpath=require('path');
-varfs=require('fs');
-varsuccesses=0;
+constpath=require('path');
+constfs=require('fs');
 
-varfile=path.join(common.fixturesDir,'a.js');
+constfile=path.join(common.fixturesDir,'a.js');
 
-fs.open(file,'a',0o777,function(err,fd){
-if(err)throwerr;
+fs.open(file,'a',0o777,common.mustCall(function(err,fd){
+assert.ifError(err);
 
 fs.fdatasyncSync(fd);
-successes++;
 
 fs.fsyncSync(fd);
-successes++;
 
-fs.fdatasync(fd,function(err){
-if(err)throwerr;
-successes++;
-fs.fsync(fd,function(err){
-if(err)throwerr;
-successes++;
-});
-});
-});
-
-process.on('exit',function(){
-assert.equal(4,successes);
-});
+fs.fdatasync(fd,common.mustCall(function(err){
+assert.ifError(err);
+fs.fsync(fd,common.mustCall(function(err){
+assert.ifError(err);
+}));
+}));
+}));