add lint and fix some issue

[kazeburo]

User description

• add golangci.yml and make lint
• fix lint issues

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PR Type

Enhancement, Tests, Bug fix

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Description

• Add golangci-lint configuration and Makefile target

• Improve error handling and logging in main

• Refactor test helpers for safer cleanup

• Pre-allocate slice capacity to optimize performance

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Diagram Walkthrough

flowchart LR
  Config["Add .golangci.yml & Makefile lint target"] --> ErrorHandling["Improve error handling & logging"]
  ErrorHandling --> Tests["Refactor test cleanup helpers"]
  Tests --> Perf["Pre-allocate slices & reduce complexity"]

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File Walkthrough

	Relevant files
Enhancement	command.go Pre-allocate slice capacity for metric results                      internal/statworker/command.go Pre-allocates slice capacity to 5 for better performance +1/-1
Tests	stat_test.go Refactor temporary file cleanup in test helpers                    internal/statworker/stat_test.go Updates tmpFileWithContent to return a cleanup function Replaces manual os.Remove with deferred cleanup calls +17/-12  main_test.go Handle server serve errors gracefully in tests                      main_test.go Wraps srv.Serve in a goroutine with error logging Prevents silent failures during test server startup +6/-1
Bug fix	main.go Add comprehensive error handling and logging                          main.go Adds error checking for syscall.Kill and cmd.Start Logs removal errors and handles missing socket files +23/-12
Configuration changes	.golangci.yml Add golangci-lint configuration and linter settings            .golangci.yml Introduces linter configuration with enabled static analysis tools Configures complexity thresholds and error check exclusions +37/-0    Makefile Add lint target to project Makefile                                            Makefile Adds lint target to run golangci-lint Sets 5-minute timeout for linting process +2/-0

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[github-actions]

PR Reviewer Guide 🔍

(Review updated until commit cf6a8d3)

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 2 🔵🔵⚪⚪⚪

🧪 PR contains tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Potential Variable Scope Issue The line err = os.Remove(opt.Socket) uses the assignment operator =. If the err variable is not already declared in the function scope, this will result in a compile error. Ensure err is declared earlier in the function, or change to err := os.Remove(opt.Socket) to declare it locally. err = os.Remove(opt.Socket) if err != nil && !os.IsNotExist(err) { log.Printf("%v", err) return CRITICAL }

[github-actions]

PR Code Suggestions ✨

Latest suggestions up to cf6a8d3

Explore these optional code suggestions:

Category	Suggestion	Impact
Possible issue	Fix potential variable scope issue with err assignment Ensure err is properly declared in the current scope before assignment. Using = requires err to be already defined; otherwise, it will cause a compilation error. Verify the variable's declaration location to prevent scope-related issues. main.go [132-136] - err = os.Remove(opt.Socket) - if err != nil && !os.IsNotExist(err) { - log.Printf("%v", err) - return CRITICAL - } +err := os.Remove(opt.Socket) +if err != nil && !os.IsNotExist(err) { + log.Printf("%v", err) + return CRITICAL +} Suggestion importance[1-10]: 9 __ Why: The suggestion correctly identifies a compilation error where err is assigned using = without prior declaration. Changing it to := ensures proper variable declaration in the current scope, which is critical for the code to build successfully.	High
General	Prevent blocking the check loop with time.Sleep The time.Sleep blocks the ticker loop goroutine, delaying subsequent binary modification checks. Consider using a separate goroutine or a timer channel to avoid blocking the main check loop. main.go [54-61] } else { - time.Sleep(10 * time.Second) - // sockファイルを消さないようsigkillで止める - errKill := syscall.Kill(syscall.Getpid(), syscall.SIGKILL) - if errKill != nil { - log.Printf("%v", errKill) - } + go func() { + time.Sleep(10 * time.Second) + // sockファイルを消さないようsigkillで止める + errKill := syscall.Kill(syscall.Getpid(), syscall.SIGKILL) + if errKill != nil { + log.Printf("%v", errKill) + } + }() } Suggestion importance[1-10]: 6 __ Why: Wrapping the time.Sleep and syscall.Kill in a goroutine prevents blocking the ticker loop, allowing the binary modification check to run at its intended 5-second interval. This improves responsiveness and concurrency without altering core logic.	Low

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Previous suggestions

Suggestions up to commit 6832ea0

Category	Suggestion	Impact
Possible issue	Fix undefined variable compilation error The variable err is assigned using = but is not declared in the current scope, which will cause a compilation error. Replace the assignment with a short variable declaration inside an if statement to fix the issue and properly scope the error variable. main.go [131-135] -err = os.Remove(opt.Socket) -if err != nil && !os.IsNotExist(err) { +if err := os.Remove(opt.Socket); err != nil && !os.IsNotExist(err) { log.Printf("%v", err) return CRITICAL } Suggestion importance[1-10]: 7 __ Why: The suggestion correctly identifies a potential compilation error from reusing err without declaration and proposes the idiomatic if err := ... pattern, which properly scopes the variable and resolves the issue.	Medium

Suggestions up to commit c206cde

Category	Suggestion	Impact
Possible issue	Fix assignment operator to prevent compilation error The assignment err = os.Remove(opt.Socket) will cause a compilation error if err is not already declared in this scope. Change = to := to properly declare the variable and avoid a compile-time error. main.go [131-135] -- os.Remove(opt.Socket) -+ err = os.Remove(opt.Socket) -+ if err != nil && !os.IsNotExist(err) { -+ log.Printf("%v", err) -+ return CRITICAL -+ } +err := os.Remove(opt.Socket) +if err != nil && !os.IsNotExist(err) { + log.Printf("%v", err) + return CRITICAL +} Suggestion importance[1-10]: 8 __ Why: The suggestion correctly identifies that err = will cause a compilation error if err is not previously declared in the scope. Changing it to := properly declares the variable and fixes the issue.	Medium

[github-actions]

Persistent review updated to latest commit 6832ea0

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Persistent review updated to latest commit cf6a8d3