Explain a denied GitHub device sign-in

Closes #1037

Author: rowkav09

src/settings-onboarding-page.js

@@ -0,0 +1,13 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {runInNewContext} from 'node:vm';
+import {SERVICE_SCRIPT} from '../src/settings-onboarding-page.js';
+test('GitHub device-flow denial explains that the user can start again',async()=>{
+ const nodes=new Map();const get=id=>{if(!nodes.has(id))nodes.set(id,{value:'https://cards.example',hidden:true,addEventListener(k,fn){this[k]=fn},replaceChildren(){}});return nodes.get(id)};
+ const say=(id,text)=>get(id).textContent=text;
+ const start=SERVICE_SCRIPT.indexOf('async function pollHosted(');const end=SERVICE_SCRIPT.lastIndexOf('load();');
+ const context={$:get,say,hostedFlow:true,hostedGeneration:1,api:async()=>({status:'denied'}),load(){throw Error('should not load after denial')}};
+ runInNewContext(SERVICE_SCRIPT.slice(start,end),context);await context.pollHosted(1);
+ assert.equal(get('hosted-service-result').textContent,'GitHub sign-in failed: Sign-in was not approved. Click Sign in with GitHub to try again.');
+ assert.equal(context.hostedFlow,false);
+});