<ul dir="auto">
<li>open viewLine.ts</li>
<li>after the first interface in the file type as fast as you can</li>
<li><code class="notranslate">class HorizontalRange implements EditorBrowser.IHorizontalRange</code></li>
</ul>
<p dir="auto">Please observe the 153ms stall due to <code class="notranslate">onDidSuggest</code> &gt; <code class="notranslate">refresh</code></p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/5047891/12331073/46dddcce-bae8-11e5-8ad5-d174b972478f.png"><img src="https://cloud.githubusercontent.com/assets/5047891/12331073/46dddcce-bae8-11e5-8ad5-d174b972478f.png" alt="image" style="max-width: 100%;"></a></p>
<p dir="auto">Copied from the inital issue (<a href="https://github.com/Microsoft/vscode-extensionbuilders/issues/80">https://github.com/Microsoft/vscode-extensionbuilders/issues/80</a>)</p>
<blockquote>
<p dir="auto">Let's see this scenario:</p>
<ul dir="auto">
<li>The cursor is placed on whitespace inside a method</li>
<li>The user asks for completions by pressing <code class="notranslate">CTRL + Space</code></li>
<li>The language service is being asked to provide all suggestions</li>
<li>The suggestion box pops up containing all 20k symbols</li>
<li>The user types the character <code class="notranslate">f</code></li>
<li><strong>VSCode hangs for ~8 seconds</strong> until the letter is displayed and the suggestion box shows only suggestions containing an <code class="notranslate">f</code>. (VSCode doesn't ask for suggestions twice. All the time is spent outside the language service. )</li>
<li>typing the next letter is being processed faster but it's still slow.</li>
</ul>
</blockquote>
<p dir="auto"><a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/joaomoreno/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/joaomoreno">@joaomoreno</a> fixed this issue on 2015-11-06 telling that there were too many event listeners. With the December update it has become slow again. VSCode hangs now for <strong>~10 seconds</strong> working on the same suggestion list.<br>
I really hope it's going to be fast again with the January update. It's not funny to work in huge projects now.</p>