Use utf8 for readFile and minor optimizations

Author: tshemsedinov

JavaScript/1-callbacks.js

@@ -2,11 +2,11 @@
 
 const fs = require('fs');
 
-fs.readFile('file1.txt', (err, data) => {
+fs.readFile('file1.txt', 'utf8', (err, data) => {
   console.log(err || data.toString());
-  fs.readFile('file2.txt', (err, data) => {
+  fs.readFile('file2.txt', 'utf8', (err, data) => {
     console.log(err || data.toString());
-    fs.readFile('file3.txt', (err, data) => {
+    fs.readFile('file3.txt', 'utf8', (err, data) => {
       console.log(err || data.toString());
     });
   });

JavaScript/2-promise.js

@@ -2,21 +2,21 @@
 
 const fs = require('fs');
 
-const readFile = (filename) => new Promise((resolve, reject) => {
-  fs.readFile(filename, (err, data) => {
-    if (err) reject(err);
-    else resolve(data.toString());
-  });
-});
+const readFile = (filename, encoding) =>
+  new Promise((resolve, reject) =>
+    fs.readFile(filename, encoding, (err, data) => {
+      if (err) reject(err);
+      else resolve(data.toString());
+    }));
 
-readFile('file1.txt')
+readFile('file1.txt', 'utf8')
   .then(data => {
     console.log(data);
-    return readFile('file2.txt');
+    return readFile('file2.txt', 'utf8');
   })
   .then(data => {
     console.log(data);
-    return readFile('file3.txt');
+    return readFile('file3.txt', 'utf8');
   })
   .then(data => {
     console.log(data);

JavaScript/3-promisify.js

@@ -5,14 +5,14 @@ const promisify = require('./promisify');
 
 const readFile = promisify(fs.readFile);
 
-readFile('file1.txt')
+readFile('file1.txt', 'utf8')
   .then(data => {
     console.log(data.toString());
-    return readFile('file2.txt');
+    return readFile('file2.txt', 'utf8');
   })
   .then(data => {
     console.log(data.toString());
-    return readFile('file3.txt');
+    return readFile('file3.txt', 'utf8');
   })
   .then(data => {
     console.log(data.toString());

JavaScript/4-then.js

@@ -5,7 +5,7 @@ const { promisify } = require('util');
 
 const readFile = promisify(fs.readFile);
 
-const readTextFile = filename => readFile(filename)
+const readTextFile = filename => readFile(filename, 'utf8')
   .then(data => data.toString());
 
 readTextFile('file1.txt')

JavaScript/5-catch.js

@@ -5,7 +5,7 @@ const { promisify } = require('util');
 
 const readFile = promisify(fs.readFile);
 
-const readTextFile = filename => readFile(filename)
+const readTextFile = filename => readFile(filename, 'utf8')
   .then(data => data.toString());
 
 readTextFile('file1.txt')

JavaScript/6-reject.js

@@ -5,7 +5,7 @@ const { promisify } = require('util');
 
 const readFile = promisify(fs.readFile);
 
-const readTextFile = filename => readFile(filename)
+const readTextFile = filename => readFile(filename, 'utf8')
   .then(data => data.toString());
 
 readTextFile('file1.txt')

JavaScript/a-files.js

@@ -6,9 +6,8 @@ const { promisify } = require('util');
 
 const readFile = promisify(fs.readFile);
 
-function readTextFile(filename) {
-  return readFile(filename).then(buffer => buffer.toString());
-}
+const readTextFile = filename => readFile(filename)
+  .then(buffer => buffer.toString());
 
 async(function* () {
   console.log(yield readTextFile('file1.txt'));

JavaScript/async-await/files.js

@@ -6,7 +6,7 @@ const { promisify } = require('util');
 const readFile = promisify(fs.readFile);
 
 const readTextFile = async (filename) => {
-  let data = await readFile(filename);
+  let data = await readFile(filename, 'utf8');
   return data.toString();
 };
 

JavaScript/b-errors.js

@@ -6,10 +6,8 @@ const async = require('./async');
 
 const readFile = promisify(fs.readFile);
 
-function readTextFile(filename) {
-  return readFile(filename)
-    .then(buffer => buffer.toString());
-}
+const readTextFile = filename => readFile(filename, 'utf8')
+  .then(buffer => buffer.toString());
 
 async(function* () {
   console.log(yield readTextFile('file1.txt'));

JavaScript/c-catch.js

@@ -6,10 +6,8 @@ const async = require('./async');
 
 const readFile = promisify(fs.readFile);
 
-function readTextFile(filename) {
-  return readFile(filename)
-    .then(buffer => buffer.toString());
-}
+const readTextFile = filename => readFile(filename, 'utf8')
+  .then(buffer => buffer.toString());
 
 async(function* () {
   console.log(yield readTextFile('file1.txt'));