Closure Compiler v20210907 Released!

[rish...@google.com]

Downloads:

Maven: http://search.maven.org/#search%7Cga%7C1%7Ca%3A%22closure-compiler%22

NPM: https://www.npmjs.com/package/google-closure-compiler

Release Notes:

https://github.com/google/closure-compiler/wiki/Releases

September, 7th, 2021 (v20210907)

• Moved JSC_UNUSED_PRIVATE_PROPERTY and JSC_MISSING_CONST_PROPERTY checks out of the analyzer and into the linter. The DiagnosticGroups UNUSED_PRIVATE_PROPERTY and MISSING_CONST_PROPERTY are deprecate
  
• The default input language is updated from ECMASCRIPT_2020 to ECMASCRIPT_2021.
• Fixed bug where using --rewrite_function_expressions could break the scoping of this inside arrow function bodies when not transpiling to ES5.
• Disallow setting --language_out in conjunction with --browser_featureset_year
• Correct transpilation of for await (const [pattern] of something) {}. Previously the compiler crashed for a destructuring variable declaration.
• Removed lint check for nullable return values that never return null.
• All transpilation passes now run in stage 2 (a.k.a. the optimizations phase) of a multistage compiler build.
• Add externs for maps api v3.46
• Deleted @deprecated CompilerOptions.setBrokenClosureRequiresLevel. The only thing this did was disable the MISSING_PROVIDE diagnostic group and prevent ProcessClosureProvidesAndRequires from deleting goog.requires. The first can be done via options.setWarningLevel and the second can be done via options.setPreserveClosureProvidesAndRequires.
• Removed peephole optimization folding RegExp calls to regex literals. The implementation was complex and had some subtle existing bugs, and the size savings measured on sample projects didn't justify the complexity.
• When pretty printing, print "()" for constructors with empty parameter lists.
• Fix printing of trailing commas for refactorings.