feat: add fetch module to support getting web content

src/fetch.ts

@@ -0,0 +1,29 @@
+import * as http from 'http';
+import * as https from 'https';
+
+function fetch(url: string): Promise<string> {
+    // determine the library to use (based on the url protocol)
+    const lib = url.startsWith('https://') ? https : http;
+
+    return new Promise((resolve, reject) => {
+        lib.get(url, (response) => {
+            // make sure the status code is 200
+            if (response.statusCode !== 200) {
+                reject(new Error(`Failed to load page, status code: ${response.statusCode}`));
+                return;
+            }
+
+            let data = '';
+            response.on('data', (chunk) => {
+                data += chunk;
+            });
+            response.on('end', () => {
+                resolve(data);
+            });
+        }).on('error', (err) => {
+            reject(err);
+        });
+    });
+}
+
+export default fetch;