Function argument destructuring and default value generates "syntax" error #201

alekbarszczewski · 2018-03-23T18:05:52Z

This is a:

Bug Report
Feature Request
Question
Other

Which concerns:

What is the current behaviour?

const defaultTrx = 'abc'
class Test {
  static async getLastUpdateTimestamp ({ trx }: { trx: any } = { trx: defaultTrx }) { /* do nothing */ }
}

flow check itself (flow check --strip-root) does not complain about this
this function works as expected on runtime

However when I enable babel-plugin-flow-runtime and then I start my program I get following error:

Duplicate declaration "trx"

.babelrc.js:

module.exports = {
  presets: [
    '@babel/flow',
    [ '@babel/env', {
      targets: {
        node: 'current'
      }
    }]
  ],
  plugins: [
    '@babel/proposal-class-properties',
    '@babel/proposal-object-rest-spread',
    '@babel/proposal-export-namespace',
    '@babel/proposal-decorators',
    ['root-import', {
      rootPathPrefix: '@',
      rootPathSuffix: 'src'
    }],
    ['flow-runtime', {
      assert: false,
      annotate: false
    }]
  ],
  env: {
    test: {
      plugins: ['istanbul']
    }
  }
}

Without flow-runtime plugin in .babelrc.js it works during runtime (no syntax errors) and also flow does not complain about it during flow check.

What is the expected behaviour?

It should not throw error, this is correct syntax and it's supported by flow.

Which package versions are you using?

"flow-runtime": "^0.17.0",
"babel-plugin-flow-runtime": "^0.17.0",
"@babel/preset-flow": "^7.0.0-beta.32"

The text was updated successfully, but these errors were encountered:

linonetwo · 2018-05-23T10:13:08Z

Same on me:

Module build failed: TypeError: /Users/.../src/components/Formula/index.js: Duplicate declaration "period"
  31 |     }
  32 |   }
> 33 |   focusVariable = ({ period, field, position }: { period: string, field: string, position: string }) =>
     |                      ^
  34 |     this.setState({ period, field, position });
  35 |   render() {
  36 |     const equalityOperatorIndex = 1;

And if remove babel-plugin-flow-runtime it works fine.

Some of my deps:

    "babel-plugin-flow-runtime": "^0.17.0",
    "react-scripts": "^2.0.0-next.66cc7a90",

linonetwo · 2018-06-26T06:45:23Z

It only happened when NODE_ENV=production.

s-ol · 2018-09-19T08:31:16Z

I'm having the same issue:

/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:347
      throw this.hub.buildError(id, `Duplicate declaration "${name}"`, TypeError);
      ^

TypeError: /mnt/space/notification_worker/index.handler.sms.js: Duplicate declaration "timestamp"
  107 |                 })
  108 |               */
> 109 |                 .then(({ timestamp, data }: Notification) => {
      |                          ^
  110 |                   console.log(`${timestamp}: handling ${msg.fields.routingKey} event...`);
  111 |                   return data;
  112 |                 })
    at File.buildCodeFrameError (/mnt/space/notification_worker/node_modules/@babel/core/lib/transformation/file/file.js:261:12)
    at Scope.checkBlockScopedCollisions (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:347:22)
    at Scope.registerBinding (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:504:16)
    at Scope.registerDeclaration (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:444:14)
    at Object.BlockScoped (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:189:28)
    at Object.newFn (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/visitors.js:230:17)
    at NodePath._call (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:53:20)
    at NodePath.call (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:36:14)
    at NodePath.visit (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:88:12)
    at TraversalContext.visitQueue (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/context.js:118:16)

if I work around the destructuring I get another one in a much weirder place:

/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:347
      throw this.hub.buildError(id, `Duplicate declaration "${name}"`, TypeError);
      ^

TypeError: /mnt/space/notification_worker/api/collection.js: Duplicate declaration "cache" (This is an error on an internal node. Probably an internal error.)
    at File.buildCodeFrameError (/mnt/space/notification_worker/node_modules/@babel/core/lib/transformation/file/file.js:261:12)
    at Scope.checkBlockScopedCollisions (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:347:22)
    at Scope.registerBinding (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:504:16)
    at Scope.registerDeclaration (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:444:14)
    at Object.BlockScoped (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/scope/index.js:189:28)
    at Object.newFn (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/visitors.js:230:17)
    at NodePath._call (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:53:20)
    at NodePath.call (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:36:14)
    at NodePath.visit (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:88:12)
    at TraversalContext.visitQueue (/mnt/space/notification_worker/node_modules/@babel/core/node_modules/@babel/traverse/lib/context.js:118:16)

the variable 'cache' is the one in this helper (verified by renaming, the error log changes with it):

  buildCache() {
    type Extended = Raw & Helpers;
    const cache: { [string]: Extended } = {};

    return (_id: string): Promise<Extended> => {
      if (cache[_id]) return Promise.resolve(cache[_id]);

      return this.findOne({ _id })
        .then(doc => {
          cache[_id] = doc;
          return doc;
        });
    };
  }

personally I don't see any commonality between these two cases but maybe it can help someone else figure the issue out as it seems to be related as per the error message.
Luckily in my project flow-runtime isn't used extensively so I will be able to remove it for the time being.

golmansax · 2019-02-08T19:33:54Z

Any updates on this? I'm still getting the destructuring error with babel-plugin-flow-runtime@0.18.0.

    ERROR in ./app/frontend/addresses/decorator.js
    Module build failed (from ./node_modules/babel-loader/lib/index.js):
    TypeError: ./app/frontend/addresses/decorator.js: Duplicate declaration "pinColor"
      74 |   }
      75 |
    > 76 |   getMapboxImageSrc({ pinColor }: MapboxImageOptions) {

jedwards1211 · 2019-05-01T20:59:04Z

I just ran into this myself, I will try to debug it.
Surprisingly this error happens even with {assert: false, annotate: false} options.

jedwards1211 · 2019-05-01T21:25:38Z

Okay commenting out https://github.com/codemix/flow-runtime/blob/master/packages/babel-plugin-flow-runtime/src/preTransformVisitors.js#L13 prevents the error...

jedwards1211 · 2019-05-01T21:44:13Z

Alright, the problem is that babel has already registered bindings for the function parameters before preTransformVisitors folds them into the body. So preTransformVisitors needs to remove those bindings.

jedwards1211 · 2019-05-01T22:06:25Z

@phpnode I just discovered that the existing test setup can't catch this, because it calls traverse repeatedly on the root node, creating new NodePaths/scopes on each traverse. We need to make the test transform work more like the actual babel plugin.

fix #201

jedwards1211 · 2019-05-02T17:13:11Z

fix released in v0.19.0 of babel-plugin-flow-runtime!

linonetwo · 2019-05-02T17:16:21Z

My God! Finally, thank you!

jedwards1211 added a commit that referenced this issue May 1, 2019

fix(babel-plugin-flow-runtime): fix duplicate declaration bug

708dec5

fix #201

jedwards1211 mentioned this issue May 1, 2019

fix(babel-plugin-flow-runtime): fix duplicate declaration bug #228

Closed

jedwards1211 closed this as completed in 73b138e May 2, 2019

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Function argument destructuring and default value generates "syntax" error #201

Function argument destructuring and default value generates "syntax" error #201

alekbarszczewski commented Mar 23, 2018

linonetwo commented May 23, 2018 •

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linonetwo commented Jun 26, 2018 •

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s-ol commented Sep 19, 2018

golmansax commented Feb 8, 2019 •

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linonetwo commented May 2, 2019

Function argument destructuring and default value generates "syntax" error #201

Function argument destructuring and default value generates "syntax" error #201

Comments

alekbarszczewski commented Mar 23, 2018

What is the current behaviour?

What is the expected behaviour?

Which package versions are you using?

linonetwo commented May 23, 2018 • edited Loading

linonetwo commented Jun 26, 2018 • edited Loading

s-ol commented Sep 19, 2018

golmansax commented Feb 8, 2019 • edited Loading

jedwards1211 commented May 1, 2019 • edited Loading

jedwards1211 commented May 1, 2019

jedwards1211 commented May 1, 2019

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linonetwo commented May 2, 2019

linonetwo commented May 23, 2018 •

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linonetwo commented Jun 26, 2018 •

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golmansax commented Feb 8, 2019 •

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jedwards1211 commented May 1, 2019 •

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jedwards1211 commented May 1, 2019 •

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