[refactor] Semantic function clustering: duplicate, outlier & scattered-helper consolidation across pkg/

[github-actions]

🔧 Semantic Function Clustering Analysis

Repository: github/gh-aw — 2026-06-12

Clusters Go functions across pkg/ by name and purpose to surface near-duplicate logic, misplaced (outlier) functions, scattered helpers, and generics opportunities. Every finding was verified by reading the implementation; only high-confidence, actionable items are included. Intentional patterns (per-codemod files, *_wasm.go build-tag variants, constructors/method sets, dual Markdown/Pretty render pairs) were excluded as not problems.

Summary

Metric	Value
Non-test .go files analyzed	~814 (workflow 400, cli 319, parser 43, console 26, agentdrain 10, utils 16)
Functions cataloged	~5,300
Confirmed findings	12 (3 duplicate · 2 outlier · 4 scattered-helper · 3 generics)
Overall health	✅ Already heavily refactored — these are incremental cleanups, not structural problems

1 Duplicate / Near-Duplicate Functions

1.1 Engine capability validators — pkg/workflow/agent_validation.go

• (*Compiler).validateMaxTurnsSupport (:115) & validateMaxContinuationsSupport (:141) are ~90% identical: extract config → nil if unset → log → if !engine.GetCapabilities().<Flag> return "<feature> not supported...". Differ only in config field, capability flag, feature name.
• Fix: extract validateCapabilitySupport(engine, name, isSet, enabled) error; both delegate. (Leave validateMaxToolDenialsSupport :163 — diverges with Copilot-SDK logic.)

1.2 events.jsonl scanner loop — pkg/cli

• parseEventsJSONL (gateway_logs_timeline.go:396) & parseEventsJSONLFile (copilot_events_jsonl.go:173) both open file, set maxScannerBufferSize, loop scan→TrimSpace→skip non-{→json.Unmarshal into copilotEventsJSONLEntry with the same malformed-line log. The second inlines the loop then accumulates metrics.
• Fix: parseEventsJSONLFile calls parseEventsJSONL for entries, then builds LogMetrics.

1.3 Inline-section extractor + validator triples — pkg/parser

• ExtractInlineSkills (inline_skill_extractor.go:77) vs ExtractInlineSubAgents (sub_agent_extractor.go:222) are structurally identical (FindAllStringSubmatchIndex → validate-unique → trim → collectH2Positions → extractInlineSection loop); only regex + result type differ. Validation trios mirror 1:1 (:18/:28/:44 vs :103/:123/:143).
• Fix: generic extractInlineSections[T](re, func(name,content) T) + shared validateFrontmatterFields(allowed, label); files already share extractInlineSection/collectH2Positions.

2 Outlier Functions (wrong file)

2.1 summarizeCommandOutput (pkg/cli/update_extension_check.go:547) — a generic trim+truncate-to-300+ellipsis helper, nothing version-check-specific; duplicates stringutil.Truncate (pkg/stringutil/stringutil.go:20).

• Fix: stringutil.Truncate(strings.TrimSpace(output), 300), or move trim-first variant into stringutil.

2.2 Per-engine RenderMCPConfig boilerplate (5 files) — gemini_mcp.go:12, claude_mcp.go:12, antigravity_mcp.go:12 (path ${RUNNER_TEMP}/...), opencode_mcp.go:12, crush_mcp.go:12 (path /tmp/...) all just log + delegate to renderDefaultJSONMCPConfig(...). Only the log prefix and one of two literal paths vary. (Codex/Copilot legitimately differ — keep theirs.)

• Fix: shared renderStandardJSONMCPConfig(engineName, destPath) so each file is a one-line path declaration.

3 Scattered Helpers

3.1 Three K/M number abbreviators — pkg/cli: formatTokens (health_metrics.go:220, int), formatCompactAIC (logs_format_compact.go:386, float, 5 uses), formatForecastAIC (forecast.go:1390, float, 11 uses) — same magnitude-tiered abbreviation, differing thresholds/precision.

• Fix: one abbreviateNumber(value float64, opts); all delegate.

3.2 Ad-hoc truncate vs stringutil.Truncate — logs_format_tsv.go:145 (displayTitle[:47]+"...") and update_extension_check.go:547 (2.1). Canonical helper exists and is tested.

• Fix: replace with stringutil.Truncate.

3.3 Two GitHub-URL → owner/repo extractors — parseRepoFromURL (outcome_eval.go:342, simple strings.Cut) vs parseGitHubRepoSlugFromURL (git.go:58, host-aware enterprise/SSH).

• Fix: parseRepoFromURL delegates to the complete parseGitHubRepoSlugFromURL, or document the host-agnostic intent.

3.4 Hand-rolled dedup vs sliceutil — pkg/parser: uniqueClosestScopeSuggestions (schema_errors.go:415) hand-rolls a seen map while sibling schema_suggestions.go:316 already uses sliceutil.Deduplicate; mergeAllowedArrays (tools_merger.go:184) reimplements merge+dedup over []any strings.

• Fix: use sliceutil.Deduplicate / sliceutil.MergeUnique.

4 Generics Opportunities (lower priority)

4.1 (GitHubAllowedTools).ToStringSlice (tools_types.go:249) & (GitHubToolsets).ToStringSlice (:264) — identical string(elem) loops over distinct ~string slices → func toStringSlice[T ~string](s []T) []string.

4.2 percentileInt/meanStdDevInt (forecast_montecarlo.go:272/251) & medianFloat (outcome_eval.go:308) differ only by element type → generic Percentile[T]/MeanStdDev[T]/Median[T] in a numstat helper. Low payoff (int versions use milli-AIC units) — optional.

4.3 FormatNumber (pkg/console/render.go:591) repeats the same 3-way precision block per k/M/B tier → factor scaleWithSuffix(f, divisor, suffix) (~40 lines → ~10).

Moderate / Optional

• Package-validator skeleton — validateNpxPackages (npm_validation.go:48), validatePipPackages/validateUvPackages (pip_validation.go:101/130) share loop→check→accumulate→NewValidationError; divergent registry semantics limit the win.
• TSV renderers — renderLogsTSV (logs_format_tsv.go:23) & renderLogsTSVVerbose (:107) duplicate per-row fallbacks + insights trailer (:83-88 vs :176-181); extract tsvRowDefaults + writeTSVInsights.

Recommendations (prioritized)

P1 — high impact, low risk

• Reuse stringutil.Truncate at the 3 sites (2.1, 3.2)
• parseEventsJSONLFile → parseEventsJSONL (1.2)
• Single abbreviateNumber helper (3.1)
• Dedup loops → sliceutil.Deduplicate/MergeUnique (3.4)

P2 — medium impact

• validateCapabilitySupport helper (1.1)
• Shared renderStandardJSONMCPConfig (2.2)
• Generic extractInlineSections[T] + validateFrontmatterFields (1.3)
• Consolidate GitHub-URL extractors (3.3)

P3 — optional

• Generics 4.1 / 4.2 / 4.3 · package-validator & TSV scaffolding

Metadata

Detection: parallel semantic sweep (naming-pattern clustering + read-and-verify). Excluded as intentional: codemod_*.go, *_wasm.go, constructors/method sets, dual render pairs, per-feature families (audit_*, gateway_logs_*, compile_*, add_interactive_*). No misplaced functions found in pkg/workflow.

References: §27385605537

Generated by 🔧 Semantic Function Refactoring · 574.3 AIC · ⌖ 9.19 AIC · ⊞ 9.8K · ◷

• expires on Jun 13, 2026, 4:20 PM UTC-08:00

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[github-actions]

Closing this issue as a new semantic function clustering refactoring analysis is being performed. A fresh report will be generated with updated findings.