Create promisify.js

Author: varun93

promisify.js

@@ -0,0 +1,32 @@
+const promisify = callback => arguments => {
+  return new Promise((resolve, reject) => {
+    callback.apply(null, [
+      ...arguments,
+      (err, data) => {
+        if (err) {
+          return reject(err);
+        }
+        resolve(data);
+      }
+    ]);
+  });
+};
+
+/**
+ * Usage
+ * 
+ const readFileAsArray = async (file) => {
+  try {
+    const readFile = promisify(fs.readFile);
+    const data = await readFile([file]);
+    const lines = data
+      .toString()
+      .trim()
+      .split("\n");
+      return lines;
+    } catch (error) {
+    cb(null, error);
+  }
+};
+
+ */