Merge pull request #27 from scramjetorg/feature/cleaner-samples

Feature: Cleaner samples

Author: a-tylenda

.gitignore

@@ -26,4 +26,5 @@ lerna-debug.log*
 .npm
 
 # Optional eslint cache
-.eslintcache
+.eslintcache
+**/dist/

package-lock.json

@@ -1,9 +1,9 @@
 {
   "dependencies": {
-    "markdownlint": "^0.25.0",
+    "markdownlint": "^0.25.1",
     "markdownlint-cli": "^0.30.0"
   },
   "scripts": {
-    "lint":"npx markdownlint '**/*.md' --ignore node_modules -c .markdownlint.json"
+    "lint":"npx markdownlint '**/*.md' --ignore **/node_modules/** -c .markdownlint.json"
   }
 }

package.json

@@ -1,29 +1,31 @@
 import { ReadableApp } from "@scramjet/types";
-import { PassThrough } from "stream";
 import fetch from "node-fetch";
 
-const getData = async (currency: string, baseCurrency: string) =>
-    fetch(`https://api.coinbase.com/v2/prices/${currency}-${baseCurrency}/spot`)
-        .then(res => res.json());
+async function defer(interval: number) {
+    await new Promise(res => setTimeout(res, interval));
+}
+
 /**
  * Requests external API every 3 seconds.
  * Writes crypto prices to output stream.
  *
  * @param _stream - dummy input stream
  * @param currency currency (default: 'BTC')
  * @param baseCurrency currency (default: 'USD')
+ * @param interval how often to check
  */
-const app: ReadableApp<string> = function(_stream, currency = "BTC", baseCurrency = "USD") {
-    const outputStream = new PassThrough();
-
-    setInterval(() => {
-        getData(currency, baseCurrency)
-            .then(data => {
-                outputStream.write(JSON.stringify(data) + "\r\n");
-            })
-    }, 3000);
-
-    return outputStream;
+const app: ReadableApp<string> = async function* (
+    _stream, 
+    currency = "BTC", 
+    baseCurrency = "USD", 
+    interval = 3000
+) {
+    while (true) {
+        const ref = defer(interval);
+        const data = await fetch(`https://api.coinbase.com/v2/prices/${currency}-${baseCurrency}/spot`);
+        yield JSON.stringify(await data.json()) + "\r\n";
+        await ref;
+    }
 };
 
 export default app;

samples/crypto-prices/index.ts

@@ -5,7 +5,7 @@
   "main": "index.js",
   "scripts": {
     "build": "tsc -p tsconfig.json",
-    "postbuild": "cp -r node_modules package.json dist/"
+    "postbuild": "cp -r package.json dist/ && (cd dist && npm i --only=production)"
   },
   "author": "",
   "license": "ISC",

samples/crypto-prices/package-lock.json

@@ -4,5 +4,5 @@
   },
   "include": [
     "./index.ts"
-  ],
+  ]
 }

samples/crypto-prices/package.json

@@ -37,9 +37,6 @@ npm install
 # transpile TS->JS to dist/
 npm run build
 
-# prepare standalone JS package
-cp -r node_modules package.json dist/
-
 # make a compressed package with sequence
 si pack dist