This will only fire if Claude adds `math/rand` as an import.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Chores**
* Updated code style guidelines and enhanced linting configuration to
enforce stricter code quality standards.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Motivation: add a check for a common issue I see humans and AI agents
making, so that we don't have to waste time on it in code reviews.
Resolves#42635
Note: This lint check has been mostly AI generated. I don't think it
needs a thorough review because it is not production code and not even
test code. Any issues will be obvious from usage by contributors.
Add a custom go/analysis analyzer that detects map[T]bool variables
used as sets (where only the literal `true` is ever assigned) and
suggests using map[T]struct{} instead, which is the idiomatic Go
approach for sets — zero memory for values and unambiguous semantics.
The analyzer minimizes false positives by:
- Only flagging when ALL indexed assignments use the literal `true`
- Skipping variables initialized from function calls (unknown source)
- Skipping variables reassigned from unknown sources
- Skipping function parameters and exported package-level variables
- Skipping range loop variables
Integrated as an incremental linter (new/changed code only) to avoid
breaking existing code.
Running this check on our whole codebase flags valid cases:
```
cmd/fleet/serve.go:306:2: map[string]bool used as a set; consider map[string]struct{} instead (setboolcheck)
allowedHostIdentifiers := map[string]bool{
^
cmd/fleetctl/fleetctl/generate_gitops.go:189:3: map[string]bool used as a set; consider map[string]struct{} instead (setboolcheck)
handled := make(map[string]bool, len(renames)*2)
^
cmd/fleetctl/fleetctl/generate_gitops.go:1593:2: map[uint]bool used as a set; consider map[uint]struct{} instead (setboolcheck)
m := make(map[uint]bool, len(ids))
```
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Chores**
* Added a new code analyzer to detect maps used as boolean sets and
recommend more efficient alternatives for better performance.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Scott Gress <scottmgress@gmail.com>
Co-authored-by: Scott Gress <scott@fleetdm.com>
<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#32999
Intended to get rid of these crash messages seen in CI:
```
Error: level=warning msg="[runner] Can't process results by generated_file_filter processor: can't filter issue &result.Issue{FromLinter:\"nilaway\", Text:\"\\x1b[31merror: \\x1b[0mINTERNAL ERROR(s):\\nnilaway_assertion_analyzer: nilaway_function_analyzer: skipping function \\x1b[95m`ListHostSoftware()`\\x1b[0m at /home/runner/work/fleet/fleet/server/datastore/mysql/software.go:4217:1: function too large (623 CFG blocks, exceeds limit of 500 blocks)\", Severity:\"\", SourceLines:[]string(nil), Pkg:(*packages.Package)(0xc002fe64e0), Pos:token.Position{Filename:\"/home/runner/work/fleet/fleet/$GOROOT/src/unicode/utf16/utf16.go\", Offset:0, Line:1, Column:1}, LineRange:(*result.Range)(nil), HunkPos:0, SuggestedFixes:[]analysis.SuggestedFix(nil), ExpectNoLint:false, ExpectedNoLintLinter:\"\", WorkingDirectoryRelativePath:\"$GOROOT/src/unicode/utf16/utf16.go\", RelativePath:\"$GOROOT/src/unicode/utf16/utf16.go\"}: failed to get doc (strict) of file /home/runner/work/fleet/fleet/$GOROOT/src/unicode/utf16/utf16.go: failed to parse file: open /home/runner/work/fleet/fleet/$GOROOT/src/unicode/utf16/utf16.go: no such file or directory"
```
**Related issue:** Resolves#32999
- Enhanced internal code quality tooling by implementing a custom
linting build configuration.
- Updated continuous integration workflow to utilize the new custom
build process for improved code analysis and consistency checks.
### Confirmed that running local custom `golangci-lint` build with
`nilaway` plugin catches lots of issues when run on `fleet/`:
<img width="1555" height="939" alt="Screenshot 2026-01-29 at 2 47 50 PM"
src="https://github.com/user-attachments/assets/c6a18400-fdf0-4104-97d8-e117efc28ed6"
/>
<img width="301" height="109" alt="Screenshot 2026-01-29 at 2 48 36 PM"
src="https://github.com/user-attachments/assets/b459ee7b-b391-457a-9191-17d56a80c783"
/>
### Confirmed that new incremental CI step using custom `golangci-lint`
build with `nilaway` plugin _does not_ check any `.go` files when none
have been modified, and so passes successfully (incremental check works
as expected):
<img width="337" height="197" alt="Screenshot 2026-01-29 at 2 45 24 PM"
src="https://github.com/user-attachments/assets/c7ae585e-2e10-4ebf-a3a3-96c26063f1e4"
/>
### Confirmed that new incremental CI step using custom `golangci-lint`
build with `nilaway` plugin _does_ check modified lines of `.go` files,
and so successfully flags a potentially unsafe dereference and fails the
job (incremental check works as expected):
<img width="825" height="491" alt="Screenshot 2026-01-29 at 5 50 01 PM"
src="https://github.com/user-attachments/assets/82bc5616-6fb9-4357-b8bc-c7eebc42c2d8"
/>
### Honorable mention:
`nilaway` agrees that `listHostSoftware` is a wild beast:
<img width="1277" height="190" alt="Screenshot 2026-01-29 at 5 52 32 PM"
src="https://github.com/user-attachments/assets/dfade2a8-fbcc-4bae-98f9-6bf1089620d2"
/>
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Fleet dev cycle reliability improvements**
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Victor Lyuboslavsky <2685025+getvictor@users.noreply.github.com>
<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#32999
The `modernize` linter was discussed some time ago in the backend sync.
We wanted to add it but it was not possible.
Now that it has been added to golangci-lint, we are adding it.
golangci-lint has incremental mode, where only changes vs the base
branch are linted. This is nice when adding new linters without needing
to fix the whole codebase. That said, it would be nice to `modernize`
the whole codebase.
