Functional/Immutability Enhancements - Package: pkg/cli

Applies moderate, tasteful functional/immutability improvements to three files in pkg/cli, replacing imperative var + append patterns with declarative sliceutil.Filter and sliceutil.Map calls.

Round-Robin Progress: First pass over pkg/cli. Next run will process: pkg/console

Summary of Changes

Transformative Data Operations — 3 sites improved

1. pkg/cli/mcp_list_tools.go — completeMCPListToolsArgs

Replaced a manual filter loop over commonMCPServerNames with sliceutil.Filter (the file already imported sliceutil):

// Before
var filtered []string
for _, s := range commonMCPServerNames {
    if toComplete == "" || strings.HasPrefix(s, toComplete) {
        filtered = append(filtered, s)
    }
}
return filtered, cobra.ShellCompDirectiveNoFileComp

// After
filtered := sliceutil.Filter(commonMCPServerNames, func(s string) bool {
    return toComplete == "" || strings.HasPrefix(s, toComplete)
})
return filtered, cobra.ShellCompDirectiveNoFileComp

2. pkg/cli/audit_report_analysis.go — generateFindings

Replaced pre-allocation + imperative index loop for first-3 tool names with a single sliceutil.Map call on a capped slice (file already imported sliceutil):

// Before
toolNames := make([]string, 0, min(3, len(processedRun.MissingTools)))
for i := 0; i < len(processedRun.MissingTools) && i < 3; i++ {
    toolNames = append(toolNames, processedRun.MissingTools[i].Tool)
}

// After
toolNames := sliceutil.Map(processedRun.MissingTools[:min(3, len(processedRun.MissingTools))], func(t MissingToolReport) string { return t.Tool })

3. pkg/cli/firewall_log.go — analyzeFirewallLogs

Replaced a manual filter loop over glob results with sliceutil.Filter (adds sliceutil import):

// Before
var firewallLogs []string
for _, file := range files {
    basename := filepath.Base(file)
    if strings.Contains(basename, "firewall") ||
        (strings.Contains(basename, "access") && !strings.Contains(basename, "access-")) {
        firewallLogs = append(firewallLogs, file)
    }
}

// After
firewallLogs := sliceutil.Filter(files, func(file string) bool {
    basename := filepath.Base(file)
    return strings.Contains(basename, "firewall") ||
        (strings.Contains(basename, "access") && !strings.Contains(basename, "access-"))
})

Benefits

• Immutability: All three sites eliminate var x []T mutation — values are now assigned once and not modified
• Clarity: The predicate/transform is explicit and self-contained, making intent immediately clear
• Consistency: Uses the existing sliceutil helpers already present in the file/codebase
• No behavior change: Logic is identical; only the mechanism of collection changed

Testing

• ✅ TestGenerateFindings / TestGenerateRecommendations — pass
• ✅ TestParseFirewallLog* / TestAnalyzeFirewallLogs* — pass
• ✅ make test-unit — all unit tests pass
• ✅ make fmt — code formatted correctly
• ✅ No behavioral changes — functionality is identical

References:

• §22710822934

Generated by Functional Pragmatist · ◷

• expires on Mar 6, 2026, 9:27 AM UTC