<blockquote>
<p dir="auto">Issue originally made by <a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/hzoo/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/hzoo">@hzoo</a></p>
</blockquote>
<h3 dir="auto">Roadmap/Ideas</h3>
<p dir="auto">Previous 6.0 Discussion: <a href="https://phabricator.babeljs.io/T2168" rel="nofollow">https://phabricator.babeljs.io/T2168</a></p>
<p dir="auto">Just wrote this up real quick a week ago so for some ideas we should definetely do</p>
<h4 dir="auto">Ease of use</h4>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Fix plugin ordering, edge cases in traversal and conflicting transforms
<ul dir="auto">
<li>relevant PRs: <a href="https://github.com/babel/babel/pull/3281" data-hovercard-type="pull_request" data-hovercard-url="/babel/babel/pull/3281/hovercard">#3281 experimental passPerPreset</a>, <a href="https://github.com/babel/babel/pull/3335" data-hovercard-type="pull_request" data-hovercard-url="/babel/babel/pull/3335/hovercard">#3335 Lossy traversal</a></li>
</ul>
</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> <code class="notranslate">babel init</code> (to setup a <code class="notranslate">.babelrc</code>) <a href="https://phabricator.babeljs.io/T6956" rel="nofollow">T6956</a>:</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Similarly, a <code class="notranslate">babel-plugin init</code> (to make a plugin) - <a href="https://github.com/thejameskyle/generator-babel-plugin">https://github.com/thejameskyle/generator-babel-plugin</a></li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Preset options (ex: 'loose mode' options, turning off commonjs, different env (browser, node)
<ul dir="auto">
<li>relevant PRs: <a href="https://github.com/babel/babel/pull/3331" data-hovercard-type="pull_request" data-hovercard-url="/babel/babel/pull/3331/hovercard">#3331 passing options to presets</a>, <a href="https://github.com/babel/babel/issues/3349" data-hovercard-type="pull_request" data-hovercard-url="/babel/babel/pull/3349/hovercard">#3349 configurable preset</a></li>
</ul>
</li>
</ul>
<h4 dir="auto">Internal Development</h4>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Better infrastructure release process with <a href="https://github.com/kittens/lerna">lerna</a>
<ul dir="auto">
<li>relevant PRs: <a href="https://github.com/kittens/lerna/pull/65" data-hovercard-type="pull_request" data-hovercard-url="/lerna/lerna/pull/65/hovercard">kittens/lerna#65 canary releases</a>, <a href="https://github.com/kittens/lerna/pull/29" data-hovercard-type="pull_request" data-hovercard-url="/lerna/lerna/pull/29/hovercard">kittens/lerna#29 changelog automation</a></li>
</ul>
</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Debugging/Performance Tracking
<ul dir="auto">
<li>relevant issues: <a href="https://github.com/babel/babel/pull/3283#issuecomment-173914233" data-hovercard-type="pull_request" data-hovercard-url="/babel/babel/pull/3283/hovercard">#3283 awesome <code class="notranslate">babel-generator</code> optimisation</a></li>
</ul>
</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Typechecking/Code Coverage - flow + babel-plugin-instanbul</li>
</ul>
<h4 dir="auto">Wish List</h4>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Automating generating a config of presets/plugins based on target environments (caniuse/autoprefixer, or dynamically)
<ul dir="auto">
<li>Relevant links: <a href="https://glebbahmutov.com/blog/javascript-needs-compile-step/" rel="nofollow">https://glebbahmutov.com/blog/javascript-needs-compile-step/</a></li>
</ul>
</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Other tooling intergrations (Minifying, Linting, Flow/Typescript)</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Syntax Plugins
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Move babylon out of babel repo</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Move jsx/flow out of babylon</li>
<li>relevant PRs <a href="https://github.com/babel/babel/pull/3376" data-hovercard-type="pull_request" data-hovercard-url="/babel/babel/pull/3376/hovercard">#3376</a></li>
</ul>
</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Cross-file transformations, knowing the dependency graph</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Async API</li>
</ul>
<h4 dir="auto">Community</h4>
<ul class="contains-task-list">
<li>Can always work on..
<ul dir="auto">
<li>Develop in the open more (#development slack)</li>
<li>Making it easier to contribute: better docs, easier setup, etc (do we want to use github issues again)</li>
<li>Reaching out for help with issue triage, more contributors, etc</li>
<li>Users could submit PRs with reproducible test cases instead of just posting snippets (ex: <a href="https://github.com/babel/babel/pull/3253" data-hovercard-type="pull_request" data-hovercard-url="/babel/babel/pull/3253/hovercard">#3253</a>)</li>
<li>Watch open source projects using Babel</li>
</ul>
</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Roadmap (something like this)</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> How to write plugins (<a href="https://github.com/thejameskyle/babel-handbook">https://github.com/thejameskyle/babel-handbook</a>)</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> Bring back a FAQ, add common stackoverflow/slack questions, etc.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Post a simple newsletter for what's been going on in the babel community (new plugins, blogs, videos, ideas, etc)?</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Documentation of APIs</li>
</ul>
<h3 dir="auto">💻</h3>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Would you like to work on a fix?</li>
</ul>
<h3 dir="auto">How are you using Babel?</h3>
<p dir="auto">with Expo</p>
<h3 dir="auto">Input code</h3>
<ul dir="auto">
<li>expo init (choose a bare template)</li>
<li>edit babel.config.js: add assumptions</li>
<li>expo start</li>
<li>try to open app with expo go</li>
</ul>
<h3 dir="auto">Configuration file name</h3>
<p dir="auto">babel.config.js</p>
<h3 dir="auto">Configuration</h3>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="module.exports = function(api) {
  api.cache(true);
  return {
    presets: ['babel-preset-expo'],
    assumptions: {
    },
  };
};"><pre class="notranslate"><code class="notranslate">module.exports = function(api) {
  api.cache(true);
  return {
    presets: ['babel-preset-expo'],
    assumptions: {
    },
  };
};
</code></pre></div>
<h3 dir="auto">Current and expected behavior</h3>
<p dir="auto">error when running <code class="notranslate">expo start -c</code></p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="Failed building JavaScript bundle.
node_modules\expo\AppEntry.js: Unknown option: .assumptions. Check out https://babeljs.io/docs/en/babel-core/#options for more information about options."><pre class="notranslate"><code class="notranslate">Failed building JavaScript bundle.
node_modules\expo\AppEntry.js: Unknown option: .assumptions. Check out https://babeljs.io/docs/en/babel-core/#options for more information about options.
</code></pre></div>
<h3 dir="auto">Environment</h3>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="  System:
    OS: Windows 10 10.0.19041
  Binaries:
    Node: 16.3.0 - C:\Program Files\nodejs\node.EXE
    npm: 7.16.0 - C:\Program Files\nodejs\npm.CMD
  npmPackages:
    @babel/core: ^7.9.0 =&gt; 7.14.5
    react-native: https://github.com/expo/react-native/archive/sdk-41.0.0.tar.gz =&gt; 0.63.2"><pre class="notranslate"><code class="notranslate">  System:
    OS: Windows 10 10.0.19041
  Binaries:
    Node: 16.3.0 - C:\Program Files\nodejs\node.EXE
    npm: 7.16.0 - C:\Program Files\nodejs\npm.CMD
  npmPackages:
    @babel/core: ^7.9.0 =&gt; 7.14.5
    react-native: https://github.com/expo/react-native/archive/sdk-41.0.0.tar.gz =&gt; 0.63.2
</code></pre></div>
<h3 dir="auto">Possible solution</h3>
<p dir="auto"><em>No response</em></p>
<h3 dir="auto">Additional context</h3>
<p dir="auto">Tried to follow <a href="https://babeljs.io/docs/en/babel-plugin-proposal-decorators" rel="nofollow">https://babeljs.io/docs/en/babel-plugin-proposal-decorators</a></p>
<p dir="auto">It says:</p>
<p dir="auto">When using the legacy: true mode, the setPublicClassFields assumption must be enabled to support the @babel/plugin-proposal-decorators.</p>