Set decoratorsBeforeExport to true, to match the default configuration for Ember projects

[ijlee2]

Background

@codemod-utils/ast-javascript's configurations for @babel/parser had been copied from jscodeshift. The reason was, @codemod-utils/ast-javascript could work like jscodeshift without bringing in unnecessary dependencies.

From a recent fork, I realized that it's better to set decoratorsBeforeExport to true, because it matches the default configuration for Ember projects.

According to Babel:

This option:

• is disallowed when using version: "legacy", version: "2022-03", version: "2023-01", or version: "2023-05";
• is required when using version: "2018-09";
• is optional and defaults to false when using version: "2021-12".

// decoratorsBeforeExport: false
export @decorator class Bar {}

// decoratorsBeforeExport: true
@decorator
export class Foo {}

This option was originally added to help tc39 collect feedback from the community by allowing experimentation with the proposed syntaxes. The proposal has now settled on allowing decorators either before or after export.

Notes

Changing the decoratorsBeforeExport to true may affect codemods that look at JavaScript files. In practice, however, I don't think this will occur often enough that I'd need to consider this pull request a breaking change.

For all of my codemods that depend on @codemod-utils/ast-javascript, the tests continued to pass after I patched the package by setting decoratorsBeforeExport to true.

• ember-codemod-args-to-signature
• ember-codemod-remove-ember-css-modules
• ember-codemod-rename-test-modules

However, it's worth noting that none of these codemods have something to do with decorators.