promise, async, awaitを実装

Dockerfile

@@ -0,0 +1,9 @@
+FROM --platform=linux/x86_64 node:18.15.0-slim
+
+RUN apt-get update && \
+    apt-get install -y locales git procps less
+RUN locale-gen ja_JP.UTF-8
+RUN localedef -f UTF-8 -i ja_JP ja_JP
+ENV LANG=ja_JP.UTF-8
+ENV TZ=Asia/Tokyo
+WORKDIR /async-io-problem

app.js

@@ -10,15 +10,13 @@ https.get('https://www.nicovideo.jp/ranking/genre/all?term=hour&rss=2.0&lang=ja-
       'User-Agent': 'node',
     },
   },
-  (response) => {
-    response
+  (res) => {
+    res
       .on('data', (chunk) => {
         data += chunk;
       })
-      .on('end', () => {
-
+      .on('end', () => { // getが完了したらファイルにdataを保存
+        fs.writeFile('test.txt', data, 'utf8', () => {});
       });
   }
-);
-
-fs.writeFile('test.txt', data, 'utf8', () => {});
+);

async-await-intro.js

@@ -0,0 +1,37 @@
+'use strict';
+
+const https = require('node:https');
+const fs = require('node:fs');
+
+function getContent(url) {
+  return new Promise((resolve, reject) => {
+    let data = '';
+    https.get(url, (res) => {
+      res
+        .on('data', (chunk) => {
+          data += chunk;
+        })
+        .on('end', () => {
+          resolve(data);
+        });
+    });
+  });
+}
+
+// function save(path, content) {
+//   return new Promise((resolve, reject) => {
+//     fs.writeFile(path, content, 'utf8', () =>{
+//       resolve('success');
+//     });
+//   });
+// }
+
+async function main() {
+  const url = 'https://www.nicovideo.jp/ranking/genre/all?term=hour&rss=2.0&lang=ja-jp';
+  const path = 'test.txt';
+  const content = await getContent(url);
+  fs.writeFileSync(path, content, 'utf8');
+  console.log("success");
+}
+
+main();

promise-intro.js

@@ -0,0 +1,30 @@
+'use strict';
+
+const https = require('node:https');
+const fs = require('node:fs');
+
+const promise = new Promise((resolve, reject) => {
+  let data ='';
+  https.get('https://www.nicovideo.jp/ranking/genre/all?term=hour&rss=2.0&lang=ja-jp',
+    (res) => {
+      console.log('status:', res.statusCode);
+      res
+        .on('data', (chunk) => {
+          data += chunk; // チャンク：データのかけら
+        })
+        .on('end', () => {
+          resolve(data);
+        });
+    }
+  );
+});
+
+promise.then((data) => {
+  return new Promise((resolve, reject) => {
+    fs.writeFile('test.txt', data, 'utf8', () => {
+      resolve('success');
+    });
+  });
+}).then((message) => {
+  console.log(message);
+})