Duplicate declaration error with Babel 7, React preset and regenerator transform plugin. #8525
Description
Bug Report
Current Behavior
$ babel ./test.js --no-babelrc --presets=module:@babel/preset-react --plugins=module:@babel/plugin-transform-regenerator
TypeError: /Users/stevefar/sc/labeltron/test.js: Duplicate declaration "newSessionId" (This is an error on an internal node. Probably an internal error.)
at File.buildCodeFrameError (/Users/stevefar/sc/labeltron/node_modules/@babel/core/lib/transformation/file/file.js:259:12)
at Scope.checkBlockScopedCollisions (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/scope/index.js:347:22)
at Scope.registerBinding (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/scope/index.js:504:16)
at Scope.registerDeclaration (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/scope/index.js:444:14)
at Object.Declaration (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/scope/index.js:125:12)
at NodePath._call (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/path/context.js:53:20)
at NodePath.call (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/path/context.js:40:17)
at NodePath.visit (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/path/context.js:88:12)
at TraversalContext.visitQueue (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/context.js:118:16)
at TraversalContext.visitMultiple (/Users/stevefar/sc/labeltron/node_modules/@babel/traverse/lib/context.js:85:17)
Input Code
The is the contents of test.js
<Component>
{() => {
const saveSession = async () => {
const newSessionId = await someAsyncFunc();
};
}}
</Component>;Expected behavior/code
I get a runtime error running babel, I expected it to create the transpiled code.
Babel Configuration (.babelrc, package.json, cli command)
babel ./test.js --no-babelrc --presets=module:@babel/preset-react --plugins=module:@babel/plugin-transform-regenerator
Environment
- Babel version(s): 7.0.0-rc.2 (@babel/core 7.0.0-rc.2)
- Node/npm version: Node 8/npm 5
- OS: OSX 10.13.6
- Monorepo no
- How you are using Babel: cli
Additional context/Screenshots
If I do each transform as a individual step it works:
$ cat ./test.js | babel --no-babelrc --presets=module:@babel/preset-react | babel --no-babelrc --plugins=module:@babel/plugin-transform-regenerator
Its not clear why this would work, but including both the preset and plugin would not.