with promises

Signed-off-by: Arnav Gupta <[email protected]>

Author: championswimmer

Lecture11/3-file-sort/out2.txt

@@ -0,0 +1 @@
+,,,1,2,3,3,3,4,4,4,5,5,5,6,6,7,7,8,24,24,26,34,34,35,35,35,42,43,46,46,46,52,52,52,52,52,53,56,56,57,57,58,67,68,69,73,78,86,234,234,237,243,245,245,245,245,245,324,357,357,425,457,462,524,524,524,532,563,567,573,624,624,624,656,735,875,876,2346,2354,3245,4224,4624,6245,7987,9857,32345,56345,56746,56756,56789,456785

Lecture11/3-file-sort/sort-p.js

@@ -0,0 +1,18 @@
+const fs = require('fs').promises
+const os = require('os')
+os.EOL // instead of '\n'
+
+Promise.all([
+  fs.readFile(__dirname + '/1.txt'),
+  fs.readFile(__dirname + '/2.txt'),
+  fs.readFile(__dirname + '/3.txt')
+]).then((arr) => {
+  let nums = []
+  arr.forEach((fileData) => {
+    nums = nums.concat(fileData.toString().split(os.EOL))
+  })
+  nums = nums.sort((a, b) => a - b)
+  return fs.writeFile(__dirname + '/out2.txt', nums)
+}).then(() => {
+  console.log('All done!')
+})

Lecture11/promises/promises.js

@@ -26,34 +26,46 @@ function readFile3(path) {
       reject(new Error('Path invalid'))
     }
     setTimeout(() => {
-      resolve('Sample data 3')
+      resolve()
     }, 3000)
   })
 }
 
 function writeFile(data1, data2, data3, done) {
   return new Promise((resolve, reject) => {
+    if (!data1 || !data2 || !data3) {
+      reject(new Error('Missing data'))
+    }
     setTimeout(() => {
       console.log('data written', [data1, data2, data3])
-      resolve()
+      resolve('Sample data 3')
     }, 2000)
   })
 }
 
+
 let errH = (err) => {
   if (err) console.error(err)
 }
 
-readFile1('asdasd')
-  .then((data1) => {
-    readFile2('')
-      .then((data2) => {
-        readFile3('dgngdn')
-          .then((data3) => {
-            writeFile(data1, data2, data3)
-          })
-          .catch(errH)
-      })
-      .catch(errH)
-  })
-  .catch(errH)
+// readFile1('asdasd')
+//   .then((data1) => {
+//     readFile2('jhgjujh')
+//       .then((data2) => {
+//         readFile3('dgngdn')
+//           .then((data3) => {
+//             writeFile(data1, data2, data3)
+//               .catch(errH)
+//           })
+//           .catch(errH)
+//       })
+//       .catch(errH)
+//   })
+//   .catch(errH)
+
+Promise.all([
+  readFile1('asdasd'),
+  readFile2('adfadf'),
+  readFile3('jgcvjhgc')
+]).then((arr) => writeFile(...arr))
+.catch(errH)