feat(var-naming): restore golint behavior by default, backwards-compatible rename and invert skipPackageNameCollisionWithGoStd

[chaimleib]

Fixes #1602.

Motivation

As described in #1602, an empty config should result in behavior like golint, according to the RULES_DESCRIPTIONS.md for var-naming:

By default, the rule behaves exactly as the alternative in golint but optionally, you can relax it (see golint/lint/issues/89).

This contract broke between v1.12.0 and v1.13.0 when skipPackageNameCollisionWithGoStd was added in #1540.

Changes

• Replace {skip->check}PackageNameCollisionWithGoStd
  • Invert the logic of that flag accordingly.
  • Update RULES_DESCRIPTIONS.md to reflect the change.
  • Fix existing tests.
  • Add a new test that an empty config behaves like golint, skipping the check on package name collisions with the Go stdlibs.
• feat: Deprecate and gracefully translate skipPackageNameCollisionWithGoStd, if provided, with a warning.
  • To show the deprecation message, allow logging at slog.LevelWarn and above, even when not in DEBUG mode.
  • When in DEBUG mode, slog.LevelDebug messages were being suppressed, since slog.LevelDebug < 0, with 0 being the default and equal to slog.LevelInfo. Now DEBUG mode will emit debug-level messages.

Testing

Makefile targets

make lint test passes.

Comparison with golint

Given the following folder structure:

http/
    http.go

And given the following content of http.go:

# Package http contains helpers.
package http

The original behavior of golint gives no errors.

$ go install golang.org/x/lint/golint@latest
$ cd http
$ golint .

The current master branch at e174d6d gives an error:

$ cd path/to/revive
$ git switch master
$ make build
$ cd ../http
$ ../revive/revive .
http.go:2:9: avoid package names that conflict with Go standard library package names

The modified revive gives no errors.

$ cd ../revive
$ git switch fix/var-naming/1602-default-golint-behavior
$ make build
$ cd ../http
$ ../revive/revive .

Enabling the check

Build the modified revive.

$ cd ../revive
$ git switch fix/var-naming/1602-default-golint-behavior
$ make build

Make the http dir like so:

http/
    http.go
    revive.toml

http.go

# Package http contains helpers.
package http

revive.toml

enableAllRules = false

[rule.var-naming]
  arguments = [ [], [], [{ checkPackageNameCollisionWithGoStd = true }] ]

An error should appear when run.

$ cd ../http
$ ../revive/revive .
http.go:2:9: avoid package names that conflict with Go standard library package names

Logging tests

All the below tests start from this basic state. Create a folder named http like so:

http/
    http.go
    revive.toml

http.go

# Package http contains helpers.
package http

revive.toml

enableAllRules = false

[rule.var-naming]
  arguments = []

Build revive:

$ cd path/to/revive
$ make build

Navigate to the http folder:

$ cd path/to/http

Empty arguments

$ path/to/revive/revive .
$ ls
http.go  revive.toml

No errors, just like golint.

Debug mode, empty arguments

$ DEBUG=y path/to/revive/revive .
time=2025-12-05T01:46:23.699-07:00 level=INFO msg="Logger initialized" logFile=revive.log
time=2025-12-05T01:46:23.699-07:00 level=INFO msg="Config loaded" rules=[var-naming]

$ ls
http.go  revive.log  revive.toml

$ cat revive.log
time=2025-12-05T01:46:23.699-07:00 level=INFO msg="Logger initialized" logFile=revive.log
time=2025-12-05T01:46:23.699-07:00 level=INFO msg="Config loaded" rules=[var-naming]

The command creates revive.log. No errors, just INFOs.

With deprecated skip option true

Edit revive.toml:

enableAllRules = false

[rule.var-naming]
  arguments = [ [], [], [{ skipPackageNameCollisionGoStd = true }]]

$ path/to/revive/revive .
time=2025-12-05T01:40:48.454-07:00 level=WARN msg="an option in the configuration is deprecated, attempting to interpret it and continue" deprecated_option=skipPackageNameCollisionWithGoStd suggestion="instead, use its inverse, checkPackageNameCollisionWithGoStd" interpreted_as=map[checkPackageNameCollisionWithGoStd:false]

Expect no errors, just a deprecation warning.

With deprecated skip option false

Edit revive.toml:

enableAllRules = false

[rule.var-naming]
  arguments = [ [], [], [{ skipPackageNameCollisionGoStd = false }]]

$ ../revive/revive .
time=2025-12-05T01:42:32.252-07:00 level=WARN msg="an option in the configuration is deprecated, attempting to interpret it and continue" deprecated_option=skipPackageNameCollisionWithGoStd suggestion="instead, use its inverse, checkPackageNameCollisionWithGoStd" interpreted_as=map[checkPackageNameCollisionWithGoStd:true]
http.go:2:9: avoid package names that conflict with Go standard library package names

Expect a deprecation warning and a lint error.

With new check option false

Edit revive.toml:

enableAllRules = false

[rule.var-naming]
  arguments = [ [], [], [{ checkPackageNameCollisionGoStd = false }]]

$ path/to/revive/revive .

Expect no errors.

[chaimleib]

I marked these commits as "feat" instead of "fix" because the config flags have changed. In semver, I think this merits incrementing the minor version in major.minor.patch, rather than the patch version.

[chaimleib]

Oops, the deprecation warning wasn't printing. I reverted that part, and I'm working on that in a separate branch based off of this.

[chaimleib]

Now the deprecation works. Users will not see breakage with their configs if this gets merged, just a deprecation warning.