Type annotation identifier does not always have range information

[platinumazure]

Upstream issue for eslint/eslint#8630.

Given this source code:

// @flow
type FieldOptions<T> = {| defaultValue: T |}
type DateFieldOptions = {| ...FieldOptions<Date> |}

This generates the AST shown at this gist.

It looks like both identifiers in FieldOptions<Date> do not get ranges:

• https://gist.github.com/platinumazure/6979435f39f6fc9dbd9ac7261a987e09#file-flow-types-json-L819-L835
• https://gist.github.com/platinumazure/6979435f39f6fc9dbd9ac7261a987e09#file-flow-types-json-L839-L855

I'm hazarding a guess that this might have to do with being preceded by the spread operator, but I can't say for sure.

Unfortunately, I don't know enough about babel-eslint or Flow to have any idea where to start with this. But if someone can give me some guidance on where to start, I could theoretically at least attempt a solution.

[rosskevin]

I'm seeing this same exact thing with flow type object spread, such as type X = {...Y}.

Cannot read property '1' of undefined
TypeError: Cannot read property '1' of undefined
    at scope.references.forEach.reference (/Users/kross/projects/ui/node_modules/eslint/lib/rules/no-use-before-define.js:206:83)
    at Array.forEach (native)
    at findVariablesInScope (/Users/kross/projects/ui/node_modules/eslint/lib/rules/no-use-before-define.js:194:30)
    at EventEmitter.Program:exit (/Users/kross/projects/ui/node_modules/eslint/lib/rules/no-use-before-define.js:242:21)
    at emitOne (events.js:101:20)
    at EventEmitter.emit (events.js:191:7)
    at NodeEventGenerator.applySelector (/Users/kross/projects/ui/node_modules/eslint/lib/util/node-event-generator.js:265:26)
    at NodeEventGenerator.applySelectors (/Users/kross/projects/ui/node_modules/eslint/lib/util/node-event-generator.js:294:22)
    at NodeEventGenerator.leaveNode (/Users/kross/projects/ui/node_modules/eslint/lib/util/node-event-generator.js:317:14)
    at CodePathAnalyzer.leaveNode (/Users/kross/projects/ui/node_modules/eslint/lib/code-path-analysis/code-path-analyzer.js:622:23)

I've tried to use the absolute latest releases though I'm unsure how there is an old babylon 6.17.1:

❯❯❯ yarn list babylon babel-eslint eslint                                                                                                                                                                                     develop ⬆ ✭ ✱
yarn list v0.21.3
├─ @alienfast/build@2.0.62
│  ├─ babel-traverse@7.0.0-alpha.12
│  │  ├─ babel-template@7.0.0-alpha.7
│  │  │  └─ babylon@7.0.0-beta.8
│  │  └─ babel-traverse@7.0.0-alpha.7
│  │  │  └─ babylon@7.0.0-beta.8
│  └─ babylon@7.0.0-beta.12
├─ babel-core@7.0.0-alpha.12
│  ├─ babel-helper-function-name@7.0.0-alpha.7
│  │  └─ babylon@7.0.0-beta.8
│  └─ babylon@7.0.0-beta.12
├─ babel-eslint@7.2.3
├─ babel-helper-remap-async-to-generator@7.0.0-alpha.12
│  ├─ babel-traverse@7.0.0-alpha.12
│  │  ├─ babel-template@7.0.0-alpha.7
│  │  │  └─ babylon@7.0.0-beta.8
│  │  └─ babel-traverse@7.0.0-alpha.7
│  │  │  └─ babylon@7.0.0-beta.8
│  └─ babylon@7.0.0-beta.12
├─ babel-helpers@7.0.0-alpha.12
│  ├─ babel-helper-function-name@7.0.0-alpha.7
│  │  └─ babylon@7.0.0-beta.8
│  └─ babylon@7.0.0-beta.12
├─ babel-plugin-transform-decorators@7.0.0-alpha.12
│  ├─ babel-helper-function-name@7.0.0-alpha.7
│  │  └─ babylon@7.0.0-beta.8
│  └─ babylon@7.0.0-beta.12
├─ babel-preset-es2016@7.0.0-alpha.12
│  ├─ babel-helper-function-name@7.0.0-alpha.7
│  │  └─ babylon@7.0.0-beta.8
│  ├─ babel-template@7.0.0-alpha.7
│  │  └─ babylon@7.0.0-beta.8
│  └─ babylon@7.0.0-beta.12
├─ babel-preset-stage-2@7.0.0-alpha.12
│  ├─ babel-traverse@7.0.0-alpha.12
│  │  ├─ babel-template@7.0.0-alpha.7
│  │  │  └─ babylon@7.0.0-beta.8
│  │  └─ babel-traverse@7.0.0-alpha.7
│  │  │  └─ babylon@7.0.0-beta.8
│  └─ babylon@7.0.0-beta.12
├─ babylon@6.17.1
└─ eslint@3.19.0

❯❯❯ yarn why babylon                                                                                                                                                                                                          develop ⬆ ✭ ✱
yarn why v0.21.3
[1/4] 🤔  Why do we have the module "babylon"...?
[2/4] 🚚  Initialising dependency graph...
[3/4] 🔍  Finding dependency...
[4/4] 🚡  Calculating file sizes...
info Has been hoisted to "babylon"
info Reasons this module exists
   - "babel-eslint" depends on it
   - "babel-eslint#babel-traverse" depends on it
   - "babel-plugin-flow-react-proptypes#babel-core" depends on it

[kentcdodds]

Thanks for the report! Do either of you think you could create a small repository to reproduce the issue and maybe even make a pull request with a fix?

[rosskevin]

Repo with reproduction:
https://github.com/rosskevin/babel-eslint-473-flow-spread

I did this quickly and did not try to pare down the other eslint plugins, but perhaps it is simple enough as is.

/related #443 #465

[soda0289]

@rosskevin I looked into this.

The problem is that there is no range information. This is because babel-eslint is not traversing into the ObjectTypeSpreadProperty node arguments. This node type was added to babel-types by this PR babel/babel#5653 but there has been no release and this means that the package babel-traverse is not including the newest type definitions.

To fix this I think there just has to be a new release of babel v6.

[rosskevin]

@soda0289 my repo is using the latest 7.x alpha, which I have seen has the original PR merged so I would expect it to work. I don't ​know the version of babel-traverse as I am mobile now, but I'll check in the morning.

[rosskevin]

I was able to do a quick check, it appears my test repo has a mixture of babel-traverse:

~/p/babel-eslint-473-flow-spread ❯❯❯ yarn list babel-traverse                                                                                                                                                                         master ✚ ✱ ◼
yarn list v0.21.3
├─ babel-eslint@7.2.3
│  └─ babel-traverse@6.24.1
├─ babel-plugin-flow-react-proptypes@3.2.0
│  └─ babel-traverse@6.24.1
├─ babel-plugin-transform-dev-warning@0.1.0
│  └─ babel-traverse@6.24.1
├─ babel-plugin-transform-react-remove-prop-types@0.4.5
│  └─ babel-traverse@6.24.1
└─ babel-traverse@7.0.0-alpha.12
│  └─ babel-traverse@7.0.0-alpha.7
✨  Done in 0.53s.

I tried to be explicit with "babel-traverse": "^7.0.0-alpha.12" in the package.json but it didn't affect the plugins' versions of it.

[kaicataldo]

Thank you for the issue. Now that @babel/eslint-parser has been released, we are making this repository read-only. If this is a change you would still like to advocate for, please reopen this in the babel/babel monorepo.