Diberry/intro code updates 2 (#39)

* support modules

* update code

nodejs-intro/.eslintrc.json

@@ -5,13 +5,21 @@
         "node": true
     },
     "extends": "eslint:recommended",
+    "parser": "@babel/eslint-parser",
     "parserOptions": {
-        "ecmaVersion": "latest"
+        "ecmaVersion": "latest",
+        "requireConfigFile": false,
+        "babelOptions": {
+            "parserOpts": {
+                "plugins": ["topLevelAwait"]
+            }
+        }
     },
     "rules": {
         "no-console": "off",
         "no-undef": "off",
         "no-unused-vars": "off",
-        "no-shadow": "off"
+        "no-shadow": "off",
+        "require-await": "error"
     }
 }

nodejs-intro/3-how-nodejs-works/async-await-top-level.js

@@ -0,0 +1,16 @@
+// top-level async/await asynchronous example
+
+const fs = require('fs').promises;
+
+const filePath = './file.txt';
+
+// `async` before the parent function
+try {
+  // `await` before the async method
+  const data = await fs.readFile(filePath, 'utf-8');
+  console.log(data);
+  console.log('Done!');
+} catch (error) {
+  console.log('An error occurred...: ', error);
+}
+console.log("I'm the last line of the file!");

nodejs-intro/3-how-nodejs-works/promise-create-basic.js

@@ -0,0 +1,24 @@
+// Create a basic promise function
+function promiseFunction() {
+    return new Promise((resolve, reject) => {
+
+        // do something
+
+        if(error){
+            // indicate success
+            reject(error)
+        } else {
+            // indicate error
+            resolve(data)
+        }
+    })
+}
+
+// Call a basic promise function
+promiseFunction()
+    .then((data) => {
+        // handle success
+    })
+    .catch((error) => {
+        // handle error
+    })

nodejs-intro/3-how-nodejs-works/promises.js

@@ -1,15 +1,16 @@
 // promises asynchronous example
 
 const fs = require('fs').promises;
-
 const filePath = './file.txt';
 
 // request to read a file
 fs.readFile(filePath, 'utf-8')
-  .then((data) => {
-    console.log(data);
-    console.log('Done!');
-  })
-  .catch((error) => {
-    console.log('An error occurred...: ', error);
-  });
+    .then((data) => {
+        console.log(data);
+        console.log('Done!');
+    })
+    .catch((error) => {
+        console.log('An error occurred...: ', error);
+    });
+
+console.log(`I'm the last line of the file!`)