mirror: linter that suggest using alternative string/[]byte functions

[butuzov]

mirror - linter suggest alternative functions while working with strings/[]byte (e.g. strings.HasPrefix and bytes.HasPrefix, if it alternative can be used).

• gocritic as experimental implementation of io.Writer and io.StringWriter detection, which is fitting to the functionality of mirror, but mirror instead checking additional functions from std lib, ignoring (for now) interface checking for io.Writer / io.StringWriter
• Currently intentionally ignoring constructions like this (in TODO)

  (&maphash.Hash{}).Write(aliasBytes("foobar"))

[ldez]

In order for a pull request adding a linter to be reviewed, the linter and the PR must follow some requirements.

• The CLA must be signed

Pull Request Description

• It must have a link to the linter repository.
• It must provide a short description of the linter.

Linter

• It must not be a duplicate of another linter or a rule of a linter. (the team will help to verify that)
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• The linter repository must have a CI and tests.
• It must use go/analysis.
• It must have a valid tag, ex: v1.0.0, v0.1.0.
• It must not contain init().
• It must not contain panic(), log.fatal(), os.exit(), or similar.
• It must not have false positives/negatives. (the team will help to verify that)
• It must have tests inside golangci-lint.

The Linter Tests Inside Golangci-lint

• They must have at least one std lib import.
• They must work with T=<name of the linter test file>.go make test_linters. (the team will help to verify that)

.golangci.reference.yml

• The linter must be added to the list of available linters (alphabetical case-insensitive order).
  • enable and disable options
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  • The default values must be defined in a comment.
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Others Requirements

• The files (tests and linter) inside golangci-lint must have the same name as the linter.
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• The load mode (WithLoadMode(...)):
  • if the linter doesn't use types: goanalysis.LoadModeSyntax
  • goanalysis.LoadModeTypesInfo required WithLoadForGoAnalysis() in the Manager.GetAllSupportedLinterConfigs(...)
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Recommendations

• The linter should not use SSA. (currently, SSA does not fully support generics)
• The linter repository should have a readme and linting.
• The linter should be published as a binary. (useful to diagnose bug origins)

---

The golangci-lint team will edit this comment to check the boxes before and during the review.

The code review will start after the completion of those checkboxes (except for the specific items that the team will help to verify).

If the author of the PR is a member of the golangci-lint team, he should not edit this message.

This checklist does not imply that we will accept the linter.

[ldez]

If the author of the PR is a member of the golangci-lint team, he should not edit this message.

[butuzov]

If the author of the PR is a member of the golangci-lint team, he should not edit this message.

After I read last line - I have uncheck "The linter must be added to the list of available linters (alphabetical case-insensitive order)." (and few others), so my hands are clear!

[hansgylling]

Don't add this linter before the data race bug is fixed: butuzov/mirror#17

[hansgylling]

Don't add this linter before the data race bug is fixed: butuzov/mirror#17

The data race bug is now fixed on the main branch in the mirror repo, but there's no new release that includes the fix yet.

[butuzov]

Don't add this linter before the data race bug is fixed: butuzov/mirror#17

The data race bug is now fixed on the main branch in the mirror repo, but there's no new release that includes the fix yet.

As I did a fix and introduced SuggestedFixes to mirror itself, I also wanted to add the ability to fix code via golangci-lint. However, I am a bit busy with military things going around. Will try to update this branch within a week or so and try to come up with a solution asap.

[bombsimon]

As I did a fix and introduced SuggestedFixes to mirror itself, I also wanted to add the ability to fix code via golangci-lint. However, I am a bit busy with military things going around. Will try to update this branch within a week or so and try to come up with a solution asap.

There's an issue for this in #1779. Also there was a fix in #2609 that got closed.

[butuzov]

Hi @bombsimon for now mirror will perform only online fixes, as multiline fixes are not supported also because I cannot spend more time digging around SuggestedFixes. That is good enough (for now).

[butuzov]

@ldez is the anything else I can do to make my PR better? (may be I am missing something)

[ldez]

This linter is closed to a gocritic rule but as those rules are experimental and the linter handles a specific case, we can accept it.
Maybe, in the future, this linter will be improved or merged into gocritic rules.

[ldez]

LGTM

For people that will watch this PR, please think to support his author: butuzov

[hansgylling]

This linter is closed to a gocritic rule but as this rule is experimental and the linter handles a specific case, we can accept it. Maybe, in the future, this linter will be improved or merged into gocritic rule.

Which gocritic rule is that? We use gocritic and I imagine that we probably use such a rule, but mirror points out other cases that our current configuration of gocritic hasn't found.

[ldez]

The following experimental go-critic rules:

• preferfprint
• preferstringwriter
• preferwritebyte

[butuzov]

LGTM

thanks!

For people that will watch this PR, please think to support his author: butuzov

And thank you again!