fix(vote): improve UX when posting comment fails

When the token doesn't have the permission to post the comment directly,
we can fallback to showing the user the error message and what command
they should type.

Author: aduh95

lib/voting_session.js

@@ -114,7 +114,7 @@ export default class VotingSession extends Session {
     const body = 'I would like to close this vote, and for this effect, I\'m revealing my ' +
                  `key part:\n\n${'```'}\n${keyPart}\n${'```'}\n`;
     if (this.postComment) {
-      const { html_url } = await this.req.json(`https://api.github.com/repos/${this.owner}/${this.repo}/issues/${this.prid}/comments`, {
+      const { message, html_url } = await this.req.json(`https://api.github.com/repos/${this.owner}/${this.repo}/issues/${this.prid}/comments`, {
         agent: this.req.proxyAgent,
         method: 'POST',
         headers: {
@@ -124,13 +124,23 @@ export default class VotingSession extends Session {
         },
         body: JSON.stringify({ body })
       });
-      this.cli.log('Comment posted at:', html_url);
-    } else if (isGhAvailable()) {
+      if (html_url) {
+        this.cli.log(`Comment posted at: ${html_url}`);
+        return;
+      } else {
+        this.cli.error('Failed to post comment');
+        this.cli.info(message);
+      }
+    }
+    if (isGhAvailable()) {
       this.cli.log('\nRun the following command to post the comment:\n');
       this.cli.log(
         `gh pr comment ${this.prid} --repo ${this.owner}/${this.repo} ` +
         `--body-file - <<'EOF'\n${body}\nEOF`
       );
+    } else {
+      this.cli.log('\nPost the following comment on the PR thread:\n');
+      this.cli.log(body);
     }
   }
 }