printer, scanner: Don't produce unparsable output. #241
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The formatter will append a newline at the end of file, causing the output of printer.Format() to be invalid.
This (invalid) Unicode codepoint is used by the printer package to fix up the indentation of generated files. If this codepoint is present in the input, the package gets confused and removes more than it should, producing unparsable output.
|
Thanks, this looks good. Note on point #2 that technically we probably should disallow any of the private use code points. I chose U+E123 because its slightly hinted at being human-made (1-2-3), but there are ~18,000 private use code points (HCL only uses one). Thanks! |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This changes fix two cases in which
printer.Format()produced output that was not accepted byparser.Parse():\x00: the scanner accepted this, because nothing is following the null byte. The formatter, however, decides to add a newline at the end of the file, assuming that this would be a no-op. Upon re-parsing, the null byte is no longer the last character in the stream and produces an error.I think that it's sane to refuse those inputs as "invalid" and I think it's very unlikely that this will break existing use-cases.