[FEATURE] Support ES2021 language features

[matz3]

By upgrading espree to the latest version, ES2021 language features
are now supported.

JIRA: CPOUI5FOUNDATION-363

[coveralls]

Coverage remained the same at 94.79% when pulling c1ca28d on upgrade-espree into 50e2c7c on next.

[RandomByte]

LGTM, @codeworrior to approve

[codeworrior]

I have to make up my mind how to properly handle chained expressions. Our check for conditional expressions wants to detect whether a certain code is always executed (eager) or not (conditional).

The following top level code

someName.memberA[(function() { sap.ui.require(["a/b/c"]); return "someProperty";}())] 

would eagerly depend on a/b/c.

But

someName.memberA?.[(function() { sap.ui.require(["a/b/c"]); return "someProperty";}())] 

would not.

This no longer can be declared statically. Within a ChainExpression.expression, the optional flag of the contained MemberExpressions has to be taken into account. If it is true, then the property part becomes conditional.

Well, but to enable the new syntax elements, the change is both required and helpful.

[matz3]

Thanks for the insights.

I also thought about handling for the ChainExpression.
But as e.g. someName.memberA && sap.ui.require(["a/b/c"]); will not result into a conditional dependency, I thought that we anyways have some cases where we could improve, so I didn't have a deeper look into all this.

What I forgot to mention:
ChainExpression is not part of the Syntax, so I first could run a build without any issues until I used a ChainExpression in the code, which resulted into an error in the JSModuleAnalyzer visit function ("Unhandled AST node type"). So maybe we need another check in the opposite direction, at least within a unit test, to ensure that we will add new node types to our code.

[codeworrior]

Reg. the gaps in espree.Syntax see eslint/js#532 (fixes eslint/js#531)

I'm waiting for OSPO to approve the (C)CLA.

[pubmikeb]

@codeworrior, thanks for contributing to the ESLint project.

Does this merge mean that UI5 Tooling 2.14.5 now supports the ES2021 language features?
If not, it would be amazing to get such support to be able using the modern JS features in UI5 apps.

[matz3]

@pubmikeb this PR got merged into the next branch which will result into the v3.0.0 release. There are prereleases available, as described in SAP/ui5-tooling#506

As the espree update requires a higher node version, we are not able to port this into the v2.x codeline.