babel: Class extends does not work in babel 6

The following code does not compile with babel 6 but throws an error (which is not very informative):

class Expression {}

export class ArrayExpression extends Expression {
}

~/source/ankara (master)$ ./node_modules/.bin/babel test.js 
Error: test.js: We don't know what to do with this node type. We were previously a Statement but we can't fit in here?
    at NodePath.insertAfter (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/path/modification.js:181:13)
    at NodePath.replaceWithMultiple (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/path/replacement.js:92:8)
    at handleClassWithSuper (/home/markusw/source/ankara/node_modules/babel-preset-stage-1/node_modules/babel-plugin-transform-class-constructor-call/lib/index.js:80:10)
    at PluginPass.Class (/home/markusw/source/ankara/node_modules/babel-preset-stage-1/node_modules/babel-plugin-transform-class-constructor-call/lib/index.js:101:11)
    at newFn (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/visitors.js:233:27)
    at NodePath._call (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/path/context.js:72:18)
    at NodePath.call (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/path/context.js:44:17)
    at NodePath.visit (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/path/context.js:102:12)
    at TraversalContext.visitQueue (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/context.js:151:16)
    at TraversalContext.visitSingle (/home/markusw/source/ankara/node_modules/babel-cli/node_modules/babel-core/node_modules/babel-traverse/lib/context.js:111:19)

My .babel.rc contains the following:

{
  "presets": ["stage-1"],
  "plugins": ["transform-async-to-generator"]
}

The following snippet does work:

class Expression {}

export class ArrayExpression {
}

About this issue

Original URL
State: closed
Created 9 years ago
Comments: 32 (6 by maintainers)

Commits related to this issue

Explicitly name classes (see https://github.com/babel/babel/issues/2700 for details). — committed to michaelahlers/presence by deleted user 9 years ago

Most upvoted comments

And… that was actually because of the order of my presets. Used ['stage-0', 'es2015', 'react'], should’ve used ['es2015', 'stage-0', 'react']

I can confirm this is fixed. Thank you so much!

elado on Nov 12, 2015

There’s an additional issue if you are setting an extended class as the default export it errors:

export default class MyComponent extends React.Component {}

Error: index.js: We don't know what to do with this node type. We were previously a Statement but we can't fit in here?
    at NodePath.insertAfter (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/path/modification.js:181:13)
    at NodePath.replaceWithMultiple (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/path/replacement.js:92:8)
    at handleClassWithSuper (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-plugin-transform-class-constructor-call/lib/index.js:80:10)
    at PluginPass.Class (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-plugin-transform-class-constructor-call/lib/index.js:101:11)
    at newFn (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/visitors.js:233:27)
    at NodePath._call (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/path/context.js:72:18)
    at NodePath.call (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/path/context.js:44:17)
    at NodePath.visit (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/path/context.js:102:12)
    at TraversalContext.visitQueue (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/context.js:151:16)
    at TraversalContext.visitSingle (/Users/thejameskyle/Projects/Tests/__babel-bug-2700/node_modules/babel-traverse/lib/context.js:111:19)

jamiebuilds on Nov 1, 2015