Optional Chaining and Nullish coalescing Operator arrived at Stage 4 #12642

g-plane · 2019-12-05T01:01:08Z

The version of ESLint you are using.
6.7

The problem you want to solve.
Support two new ES features: Optional Chaining and Nullish coalescing Operator.

Your take on the correct solution to problem.

ESTree: Add optional chaining estree/estree#204 and Add nullish coalescing support estree/estree#211
Acorn: add Nullish Coalescing acornjs/acorn#890 and add Optional Chaining acornjs/acorn#891
eslint-visitor-keys: Update: add ChainExpression node eslint-visitor-keys#12
Espree: Update: support ?? operator, import.meta, and export * as ns espree#441 and Update: support optional chaining espree#446
ESLint: Update: support ?? operator, import.meta, and export * as ns #13196 and Update: optional chaining support (fixes #12642) #13416

(Template inspired by Issue 12629)

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

franktopel · 2020-02-06T09:36:18Z

When can we hope to get this? optional chaining is a highly desirable feature, and since we dropped Babel we're waiting for Acorn to support this, so webpack can support it as well :)

kaicataldo · 2020-02-06T18:10:02Z

We're currently also waiting for Acorn to support this (our default parser, Espree, wraps Acorn), and that work is currently blocked by estree/estree#204.

eslint-deprecated · 2020-03-08T22:43:42Z

Unfortunately, it looks like there wasn't enough interest from the team
or community to implement this change. While we wish we'd be able to
accommodate everyone's requests, we do need to prioritize. We've found
that accepted issues failing to be implemented after 90 days tend to
never be implemented, and as such, we close those issues.
This doesn't mean the idea isn't interesting or useful, just that it's
not something the team can commit to.

Thanks for contributing to ESLint and we appreciate your understanding.

DaniGuardiola · 2020-05-22T21:16:46Z

I encountered this problem and figured this is the right place to mention it :)

As per this comment:

Closing as this is currently unsupported. If optional chaining becomes a Stage 4 ECMAScript proposal, we could reopen this and make any necessary changes to the core rule. Thanks!

NemoStein · 2020-05-22T22:24:44Z

As I understand, we are waiting for Optional Chaining syntax to be added to ESTree to merge this PR.
@mysticatea may correct me if I'm wrong (sorry to bug you)...

NemoStein · 2020-06-11T16:53:25Z

As commented by dreyks (#13196 (comment))

released as https://github.com/acornjs/acorn/releases/tag/7.3.0

Does it means that both Optional Chaining and Nullish coalescing Operator is part of ESLint now and this issue can be closed?

kaicataldo · 2020-06-11T16:55:03Z

Not yet. This will be closed when we integrate these upstream changes into ESLint core.

NemoStein · 2020-06-11T16:59:38Z

Right, makes sense...
Just to be sure, Optional Chaining is included in Acorn by that PR?
There was a lot of back and forth about it and I'm not sure even if Nullish coalescing Operator is in ESLint now... =|

kaicataldo · 2020-06-11T17:10:37Z

Just to be sure, Optional Chaining is included in Acorn by that PR?

The ESTree spec was just finalized yesterday, so it's going to take a little bit of time to get everything updated downstream. Hopefully we'll be able to get it out in the next release.

There was a lot of back and forth about it and I'm not sure even if Nullish coalescing Operator is in ESLint now... =|

Nullish coalescing operator was included in the latest release (v7.2.0).

* update deps (to branch) * trivial fix for debug output * update code path analysis * update accessor-pairs * update array-callback-return * add tests for camelcase * add tests for computed-property-spacing * update dot-location * update dot-notation * update func-name-matching * update global-require * update indent * add tests for getter-return * update new-cap * update newline-per-chained-call * update no-alert * update no-extend-native * update no-extra-bind * update no-extra-parens * update no-eval * update no-implicit-coercion * update eslint-utils * update no-implied-eval * update no-import-assign * update no-magic-numbers * update no-obj-calls * update no-prototype-builtins * add tests for no-restricted-syntax * update no-self-assign * update no-setter-return * update no-unexpected-multiline * update no-unused-expression * update no-useless-call * update no-whitespace-before-property * update operator-assignment * update padding-line-between-statements * update prefer-arrow-callback * add tests for prefer-destructuring * update prefer-exponentiation-operator * update prefer-numeric-literals * update prefer-promise-reject-errors * update prefer-regex-literals * update prefer-spread * update use-isnan * update yoda * update wrap-iife * remove __proto__ * fix no-import-assign for delete op * update eslint-visitor-keys * fix no-unexpected-multiline to just ignore optional chaining * update func-call-spacing * update constructor-super * update dot-location for unstable sort * update no-extra-boolean-cast * update func-call-spacing * update no-extra-parens for false positive on IIFE * update array-callback-return * update no-invalid-this (astUtils.isDefaultThisBinding) * update radix * update a comment in no-implicit-coercion * update comments in no-extra-bind * remove unnecessary change from array-callback-return * update dot-notation for autofix about `let?.[` * update new-cap * update wrap-iife * update prefer-arrow-callback * change isSameReference to handle `a.b` and `a?.b` are same * fix code path analysis for `node.arguments.length == 0` case * update `astUtils.couldBeError` * update `astUtils.isMethodWhichHasThisArg` * improve coverage * fix isMethodWhichHasThisArg * update no-self-assign * Upgrade: espree@7.2.0 Co-authored-by: Kai Cataldo <kai@kaicataldo.com>

Lonniebiz · 2020-08-02T08:41:16Z

Shouldn't this issue remain open? While Nullish coalescing may be supported, I have confirmed that Optional Chaining is not supported in (the latest) eslint 7.6.0.

SebastianSimon · 2020-08-02T10:55:14Z

@Lonniebiz It works in the online demo. What input code are you using and which warning or error do you see?

Lonniebiz · 2020-08-02T12:53:53Z

Earlier, I tested some code that looked like this:

	let obj = {};
	if (obj.data?.length === 0)
	{
		console.log(obj);
	}

I got some error griping about ?. However, now when I try it, it works. Maybe when I changed eslint.parserOptions.ecmaVersion from 2018 to 2020 it didn't take effect right away. Not sure, but thanks for the reply, which caused me to try it again and experience it working. Glad to see this one! @SebastianSimon

sevor005 · 2020-08-13T07:27:33Z

Good afternoon! Have you added support for optional chaining to eslint? If not added, which version will support it? Thanks!

marktaiwan · 2020-08-13T07:34:03Z

Good afternoon! Have you added support for optional chaining to eslint? If not added, which version will support it? Thanks!

Support for optional chaining was added in v7.5.0
https://eslint.org/blog/2020/07/eslint-v7.5.0-released

sevor005 · 2020-08-13T07:37:52Z

Good afternoon! Have you added support for optional chaining to eslint? If not added, which version will support it? Thanks!

Support for optional chaining was added in v7.5.0
https://eslint.org/blog/2020/07/eslint-v7.5.0-released

Thank you very much!

g-plane added enhancement This change enhances an existing feature of ESLint core Relates to ESLint's core APIs and features accepted There is consensus among the team that this change meets the criteria for inclusion labels Dec 5, 2019

mysticatea added the new syntax This issue is related to new syntax that has reached stage 4 label Dec 5, 2019

mysticatea pinned this issue Dec 5, 2019

iansan5653 mentioned this issue Dec 7, 2019

no-unused-expressions warning for optional chaining facebook/create-react-app#8107

Open

jrieken mentioned this issue Jan 3, 2020

tslint to eslint migration microsoft/vscode#87644

Merged

14 tasks

aladdin-add mentioned this issue Jan 14, 2020

Rule id-blacklist incorrectly flags object property reassignments #12787

Closed

tmsns mentioned this issue Mar 4, 2020

[eslint-config] Support optional chaining open-wc/open-wc#1223

Closed

eslint-deprecated bot closed this as completed Mar 8, 2020

eslint-deprecated bot added the auto closed The bot closed this issue label Mar 8, 2020

g-plane reopened this Mar 8, 2020

g-plane removed the auto closed The bot closed this issue label Mar 8, 2020

mysticatea self-assigned this Mar 10, 2020

anikethsaha mentioned this issue Mar 25, 2020

camelcase with optional chaining #13093

Closed

ota-meshi mentioned this issue Mar 31, 2020

Parsing error on optional chaining (?.) token vuejs/eslint-plugin-vue#1084

Closed

anikethsaha mentioned this issue Mar 31, 2020

BigInt not support yet #13122

Closed

mysticatea mentioned this issue Apr 19, 2020

Update: support ?? operator, import.meta, and export * as ns #13196

Merged

30 tasks

aladdin-add mentioned this issue Apr 30, 2020

Consider nullish coalescing in code path analyzer #13237

Closed

bradzacher mentioned this issue Jun 11, 2020

Update optional chaining representation to match ESTree spec typescript-eslint/typescript-eslint#2204

Closed

3 tasks

mysticatea mentioned this issue Jun 13, 2020

Update: optional chaining support (fixes #12642) #13416

Merged

53 tasks

kaicataldo added a commit that referenced this issue Jul 18, 2020

Upgrade: espree@7.2.0 (refs #12642)

90b4e3e

kaicataldo closed this as completed in #13416 Jul 18, 2020

mysticatea unpinned this issue Jul 21, 2020

pfongkye mentioned this issue Aug 25, 2020

Fixes eslint warning when node type is ChainExpression facebook/react#19680

Merged

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eslint-deprecated bot added the archived due to age This issue has been archived; please open a new issue for any further discussion label Jan 15, 2021

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Optional Chaining and Nullish coalescing Operator arrived at Stage 4 #12642

Optional Chaining and Nullish coalescing Operator arrived at Stage 4 #12642

g-plane commented Dec 5, 2019 •

edited by mysticatea

franktopel commented Feb 6, 2020

kaicataldo commented Feb 6, 2020

eslint-deprecated bot commented Mar 8, 2020

DaniGuardiola commented May 22, 2020

NemoStein commented May 22, 2020

NemoStein commented Jun 11, 2020 •

edited

kaicataldo commented Jun 11, 2020

NemoStein commented Jun 11, 2020

kaicataldo commented Jun 11, 2020

Lonniebiz commented Aug 2, 2020 •

edited

SebastianSimon commented Aug 2, 2020

Lonniebiz commented Aug 2, 2020 •

edited

sevor005 commented Aug 13, 2020

marktaiwan commented Aug 13, 2020

sevor005 commented Aug 13, 2020

Optional Chaining and Nullish coalescing Operator arrived at Stage 4 #12642

Optional Chaining and Nullish coalescing Operator arrived at Stage 4 #12642

Comments

g-plane commented Dec 5, 2019 • edited by mysticatea

franktopel commented Feb 6, 2020

kaicataldo commented Feb 6, 2020

eslint-deprecated bot commented Mar 8, 2020

DaniGuardiola commented May 22, 2020

NemoStein commented May 22, 2020

NemoStein commented Jun 11, 2020 • edited

kaicataldo commented Jun 11, 2020

NemoStein commented Jun 11, 2020

kaicataldo commented Jun 11, 2020

Lonniebiz commented Aug 2, 2020 • edited

SebastianSimon commented Aug 2, 2020

Lonniebiz commented Aug 2, 2020 • edited

sevor005 commented Aug 13, 2020

marktaiwan commented Aug 13, 2020

sevor005 commented Aug 13, 2020

g-plane commented Dec 5, 2019 •

edited by mysticatea

NemoStein commented Jun 11, 2020 •

edited

Lonniebiz commented Aug 2, 2020 •

edited

Lonniebiz commented Aug 2, 2020 •

edited