fix: import sass file even if not listed in package.json

[roger6106]

Description

Closes #2499.

Vite currently does not work when using @material packages, with no functional workaround. When attempting to load a sass file, the package.json is checked and the main file (which is javascript) is loaded instead of _index.scss. This change adds an additional check specifically for sass files, making sure that the retrieved extension from package.json matches an existing extension. If not, it falls back to the extension method of determining an index file.

Additional context

The tryResolveFile() method has a tryIndex parameter, which uses package.json (if it exists), and then falls back to trying index plus extension / prefix. I add an additional optional skipPackage parameter which is used when a sass extension doesn't match.

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

Thanks for the PR @roger6106. I tested locally and the new tests are passing even when I remove the fix in this PR. They look good to me but seems that Vite was already working correctly in this case. I don't know what difference the issue has that indeed is fixed by your PR. Could you check if new tests could be added that fails without your fix?

[roger6106]

Sorry about that. I have corrected the test.

[roger6106]

@Shinigami92: Can you take a look at this again? There's not a functional workaround in my situation, and I'm having to hack SvelteKit so that I keep this change functional with it.