path.buildCodeFrameError('Error') throws

[pasaran]

Bug Report

Current Behavior
path.buildCodeFrameError( 'Some error' ) throws error:

/Users/nop/tmp/node_modules/@babel/traverse/lib/path/index.js:157
    return this.hub.buildError(this.node, msg, Error);
                    ^

TypeError: Cannot read property 'buildError' of undefined
    at NodePath.buildCodeFrameError (/Users/nop/tmp/node_modules/@babel/traverse/lib/path/index.js:157:21)
    at Program (/Users/nop/tmp/test.js:9:20)
    at NodePath._call (/Users/nop/tmp/node_modules/@babel/traverse/lib/path/context.js:53:20)
    at NodePath.call (/Users/nop/tmp/node_modules/@babel/traverse/lib/path/context.js:40:17)
    at NodePath.visit (/Users/nop/tmp/node_modules/@babel/traverse/lib/path/context.js:88:12)
    at TraversalContext.visitQueue (/Users/nop/tmp/node_modules/@babel/traverse/lib/context.js:118:16)
    at TraversalContext.visitSingle (/Users/nop/tmp/node_modules/@babel/traverse/lib/context.js:90:19)
    at TraversalContext.visit (/Users/nop/tmp/node_modules/@babel/traverse/lib/context.js:146:19)
    at Function.traverse.node (/Users/nop/tmp/node_modules/@babel/traverse/lib/index.js:94:17)
    at traverse (/Users/nop/tmp/node_modules/@babel/traverse/lib/index.js:76:12)

Input Code

const parser = require( '@babel/parser' );
const traverse = require( '@babel/traverse' ).default;
const { codeFrameColumns } = require( '@babel/code-frame' );

const CODE = 'var a = 1;';
const ERROR = 'Number is too small';

const ast = parser.parse( CODE );

traverse( ast, {
    NumericLiteral: function( path ) {
        throw path.buildCodeFrameError( 'Some error' );
        //  throw codeFrameColumns( CODE, path.node.loc, ERROR );
    },
} );

Expected behavior/code
throw path.buildCodeFrameError( ERROR ) should do the same as throw codeFrameColumns( CODE, path.node.loc, ERROR ); (I guess).

Babel Configuration (.babelrc, package.json, cli command)

//  package.json:

  "devDependencies": {
    "@babel/parser": "^7.0.0",
    "@babel/traverse": "^7.0.0"
  }

Environment

• Babel version(s): 7.0.0
• Node/npm version: v9.0.0
• OS: OSX 10.12.6 (16G1408)
• How you are using Babel: cli

[babel-bot]

Hey @pasaran! We really appreciate you taking the time to report an issue. The collaborators
on this project attempt to help as many people as possible, but we're a limited number of volunteers,
so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack
community that typically always has someone willing to help. You can sign-up here
for an invite.

[loganfsmyth]

Strange, I'd expect it to have that function from

babel/packages/babel-traverse/src/hub.js

Line 19 in 59e9c63

buildError(node, msg, Error = TypeError): Error {

Maybe we missed initializing this.hub somewhere.

[monokrome]

@loganfsmyth It doesn't have that, because hub is the value that is undefined. Since hub is undefined, buildError can not be referenced. undefined.buildError throws this error.

[loganfsmyth]

It looks like I probably pasted the wrong link when I posted that, woops.

[monokrome]

@loganfsmyth I'm running into this right now - where were you intending to link to?

[loganfsmyth]

I honestly think at the moment we just don't ever set a default hub, and there is no way to set it via traverse without doing the same stuff that Babel itself does to set up the initial traversal.

Depending on your usecase for buildCodeFrameError, it might make more sense to use @babel/core to trigger the traversal. Otherwise, I'd avoid using buildCodeFrameError in your code. If you're seeing it error in code other that your own, then it's still an indication of an error, it's just failing to throw a nice error for you.

[monokrome]

When I import { generate } from '@babel/core', it doesn't actually exist. Is there a way to get a reference to and pass the hub manually?

[loganfsmyth]

Sorry, I don't quite follow what you're using generate for in this context. Would you be up for joining our Slack to continue this discussion? I think it's hard to have back-and-forth like this on Github.

[lcoder]

Hub. buildError
It seems that the features have not been implemented

node parameter is not used

I solved with

const code = require( '@babel/generator' ).default( path.node , {} ).code
throw new Error( `\n${code}\n ^^^^ your message` )

[motiz88]

Some version of this issue seems to have been reintroduced by #10914 in 7.8.0.

Before 7.8.0, @babel/core's parseSync would call normalizeFile which in turn would initialise hub, so traverseing and calling path.buildCodeFrameError worked.

Since 7.8.0, @babel/core's parseSync does not call normalizeFile, so hub isn't initialised and calling path.buildCodeFrameError within a traversal fails again.

[skipjack]

Yeah I'm still seeing this error when using parcel but only when building for production (i.e. parcel serve works fine but parcel build fails). Reverting babel to an older version based on @motiz88's comment above to see if that addresses the issue (doesn't feel like a great fix though, would love to help find a cleaner solution).

Update: Installing older versions of @babel/core and @babel/traverse didn't work for me. That doesn't mean it won't work for anyone but at least with parcel@2.0.0-beta.1 I still get the following error: