fix-lint

Prompt file imported from solarwinds/swo-cli (.github/prompts/fix-lint.prompt.md). Copyright stays with the author.

Fix Go Linting Issues

Overview

This prompt helps you fix common Go linting issues found by golangci-lint in the SWO CLI codebase.

Instructions

Use this prompt to fix the most common linting violations in Go code. Run make lint first to see current issues, then use this prompt to fix them systematically.

Common Linting Issues and Solutions

1. err113: Dynamic Error Creation

Issue: do not define dynamic errors, use wrapped static errors instead

Problem Code:

return errors.New("some dynamic error message")

Fix:

// Define static errors at package level
var (
    ErrSomeCondition = errors.New("some error message")
)

// Use in functions
return ErrSomeCondition
// Or wrap with context
return fmt.Errorf("additional context: %w", ErrSomeCondition)

2. errcheck: Unchecked Error Returns

Issue: Error return value of 'function' is not checked

Problem Code:

file.Close()
json.NewEncoder(w).Encode(data)
os.Remove(filename)

Fix:

// For defer statements in tests (where error handling isn't critical)
defer func() { _ = file.Close() }()

// For regular code, handle appropriately
if err := json.NewEncoder(w).Encode(data); err != nil {
    return fmt.Errorf("failed to encode response: %w", err)
}

// For cleanup operations where errors are expected
if err := os.Remove(filename); err != nil && !os.IsNotExist(err) {
    t.Logf("Failed to remove temp file: %v", err)
}

3. revive: Exported Function Comments

Issue: comment on exported method should be of the form "MethodName ..."

Problem Code:

// Validate validates the options for different operations
func (o *Options) ValidateForGet() error {

Fix:

// ValidateForGet validates the options for get operations
func (o *Options) ValidateForGet() error {

4. revive: Unused Parameters

Issue: parameter 'name' seems to be unused, consider removing or renaming it as _

Problem Code:

func handler(w http.ResponseWriter, r *http.Request) {
    // r is not used
    w.WriteHeader(200)
}

Fix:

func handler(w http.ResponseWriter, _ *http.Request) {
    w.WriteHeader(200)
}

5. staticcheck: Tagged Switch

Issue: could use tagged switch on variable

Problem Code:

if tc.name == "case1" {
    // handle case1
} else if tc.name == "case2" {
    // handle case2
}

Fix:

switch tc.name {
case "case1":
    // handle case1
case "case2":
    // handle case2
}

Test-Specific Patterns

Error Handling in Tests

// For file operations in tests
defer func() {
    if err := os.Remove(tempFile.Name()); err != nil && !os.IsNotExist(err) {
        t.Logf("Failed to cleanup temp file: %v", err)
    }
}()

// For closing resources in tests
defer func() {
    if err := tempFile.Close(); err != nil {
        t.Logf("Failed to close temp file: %v", err)
    }
}()

HTTP Response Writing in Test Handlers

// Instead of ignoring the error
w.Write([]byte("response"))

// Handle it appropriately for tests
if _, err := w.Write([]byte("response")); err != nil {
    t.Errorf("Failed to write response: %v", err)
    return
}

Workflow

1. Run make lint to see current issues
2. Use the patterns above to fix each type of issue
3. Run make fix-lint to auto-fix formatting
4. Run make lint again to verify fixes
5. Commit the changes

SWO CLI Specific Patterns

Error Definitions

Define package-level errors in each package:

// In entities/errors.go
var (
    ErrMissingEntityID   = errors.New("entity ID is required")
    ErrMissingEntityType = errors.New("entity type is required")
    ErrInvalidTag        = errors.New("invalid tag format, expected key=value")
    ErrAtLeastOneTag     = errors.New("at least one tag is required for update")
)

API Client Error Handling

// In client methods
if response.StatusCode < 200 || response.StatusCode > 299 {
    return fmt.Errorf("%w: %d, response body: %s", ErrInvalidAPIResponse, response.StatusCode, string(content))
}

Configuration Error Handling

// In config package
if config.Token == "" {
    return nil, ErrMissingToken
}
if config.APIURL == "" {
    return nil, ErrMissingAPIURL
}

Remember: Good error handling makes the CLI more user-friendly and debuggable!