js_examples: Migrate and test update_message example.

templates/zerver/api/update-message.md

@@ -12,24 +12,8 @@
 {tab|js}
 
 More examples and documentation can be found [here](https://github.com/zulip/zulip-js).
-```js
-const zulip = require('zulip-js');
 
-// Pass the path to your zuliprc file here.
-const config = {
-    zuliprc: 'zuliprc',
-};
-
-zulip(config).then((client) => {
-    // Update a message
-    const params = {
-        message_id: 131,
-        content: 'New Content',
-    }
-
-    client.messages.update(params).then(console.log);
-});
-```
+{generate_code_example(javascript)|/messages/{message_id}:patch|example}
 
 {tab|curl}
 

zerver/openapi/javascript_examples.js

@@ -51,6 +51,7 @@ const ExamplesHandler = function () {
         await generate_validation_data(client, examples.add_subscriptions);
         await generate_validation_data(client, examples.remove_subscriptions);
         await generate_validation_data(client, examples.update_message_flags);
+        await generate_validation_data(client, examples.update_message);
 
         console.log(JSON.stringify(response_data));
         return;
@@ -302,4 +303,25 @@ add_example('update_message_flags', '/messages/flags:post', 200, async (client)
     return [result_1, result_2];
 });
 
+add_example('update_message', '/messages/{message_id}:patch', 200, async (client) => {
+    const request = {
+        to: 'Denmark',
+        type: 'stream',
+        topic: 'Castle',
+        content: 'I come not, friends, to steal away your hearts.',
+    };
+    const result = await client.messages.send(request);
+    const message_id = result.id;
+
+    // {code_example|start}
+    // Update a message with the given "message_id"
+    const params = {
+        message_id: message_id,
+        content: 'New Content',
+    };
+
+    return await client.messages.update(params);
+    // {code_example|end}
+});
+
 main();