feat(rules): add SLP223-227, retire noise rules, consolidate error rules

pkg/rules/RETIRED.md

@@ -0,0 +1,51 @@
+# Retired & Consolidated Rules
+
+## Policy
+
+Rules are retired from the default rule set when benchmarked data shows
+they produce high noise-to-signal ratios on real repositories. Retired
+source files are kept in the repo with a `//go:build ignore_retired`
+build tag — they compile only when explicitly requested (`-tags ignore_retired`).
+
+Rules are **consolidated** when their concern is fully covered by a
+newer, more precise rule. Consolidated files are deleted from the repo.
+
+## Curation Log
+
+### 2026-06-20 — Whimsy benchmark curation
+
+Trigger: Whimsy 15-day benchmark showed 7 rules with <5% useful findings.
+
+**Retired (build-tagged):**
+
+| Rule | Previous findings/10 PRs | Reason |
+|------|------------------------|--------|
+| SLP043 | 244 | Duplicate JSON key heuristic fires on any struct with >2 fields sharing a prefix. Only 1 real bug pattern confirmed, 243 noise. |
+| SLP050 | 175 | Fires on every new function without param validation, including trivial getters/setters. No real bugs found. |
+| SLP055 | 45 | "Function has N conditionals without comments" — pure style heuristic. No bugs. |
+
+**Consolidated into SLP223 (deleted):**
+
+| Rule | Previous findings/10 PRs | Reason |
+|------|------------------------|--------|
+| SLP044 | 26 | `_ = err` pattern — fully covered by SLP223's targeted ignored-error detection |
+| SLP065 | 117 | Generic "ignored error return" — overlaps SLP044/SLP114/SLP120; SLP223 covers this with better precision (Close/Remove/MarkRun* etc.) |
+| SLP114 | 96 | "Error-returning function called as statement" — same class as SLP065 |
+| SLP120 | 14 | "Discarded value with `_ =`" — fully covered by SLP223 |
+
+**Narrowed:**
+
+| Rule | Change | Reason |
+|------|--------|--------|
+| SLP227 | Exclude strings <6 chars and HTTP method literals | Was flagging "GET"/"POST"/"run"/"config" etc. — 17 of 18 findings were noise from test helper/OpenAPI code |
+
+## Restoring a Retired Rule
+
+To temporarily re-enable a retired rule for a specific scan:
+
+```bash
+go run -tags ignore_retired ./cmd/slopgate --base origin/main
+```
+
+To permanently restore, remove the `//go:build ignore_retired` tag and
+add the rule registration back to `registry.go`.

pkg/rules/registry.go

@@ -44,19 +44,15 @@ func Default() *Registry {
 	r.Register(SLP040{})
 	r.Register(SLP041{})
 	r.Register(SLP042{})
-	r.Register(SLP043{})
-	r.Register(SLP044{})
 	r.Register(SLP045{})
 	r.Register(SLP046{})
 	r.Register(SLP047{})
 	r.Register(SLP048{})
 	r.Register(SLP049{})
-	r.Register(SLP050{})
 	r.Register(SLP051{})
 	r.Register(SLP052{})
 	r.Register(SLP053{})
 	r.Register(SLP054{})
-	r.Register(SLP055{})
 	r.Register(SLP056{})
 	r.Register(SLP057{})
 	r.Register(SLP058{})
@@ -66,7 +62,6 @@ func Default() *Registry {
 	r.Register(SLP062{})
 	r.Register(SLP063{})
 	r.Register(SLP064{})
-	r.Register(SLP065{})
 	r.Register(SLP066{})
 	r.Register(SLP067{})
 	r.Register(SLP068{})
@@ -117,13 +112,11 @@ func Default() *Registry {
 	r.Register(SLP111{})
 	r.Register(SLP112{})
 	r.Register(SLP113{})
-	r.Register(SLP114{})
 	r.Register(SLP115{})
 	r.Register(SLP116{})
 	r.Register(SLP117{})
 	r.Register(SLP118{})
 	r.Register(SLP119{})
-	r.Register(SLP120{})
 	r.Register(SLP121{})
 	r.Register(SLP122{})
 	r.Register(SLP123{})
@@ -194,5 +187,10 @@ func Default() *Registry {
 	r.Register(SLP220{}) // filepath.Walk without context cancellation check
 	r.Register(SLP221{}) // exec.Command without capturing stderr on failure
 	r.Register(SLP222{}) // treating UTF-16/BOM data as UTF-8 without decoding
+	r.Register(SLP223{}) // ignored error return
+	r.Register(SLP224{}) // HTTP handler missing request body/param validation
+	r.Register(SLP225{}) // goroutine mutating shared state without sync
+	r.Register(SLP226{}) // SQL resource/transaction imbalance
+	r.Register(SLP227{}) // repeated string literal
 	return r
 }

pkg/rules/registry_test.go

@@ -44,19 +44,15 @@ func TestDefault_RegistersAllV001Rules(t *testing.T) {
 		"SLP040": false,
 		"SLP041": false,
 		"SLP042": false,
-		"SLP043": false,
-		"SLP044": false,
 		"SLP045": false,
 		"SLP046": false,
 		"SLP047": false,
 		"SLP048": false,
 		"SLP049": false,
-		"SLP050": false,
 		"SLP051": false,
 		"SLP052": false,
 		"SLP053": false,
 		"SLP054": false,
-		"SLP055": false,
 		"SLP056": false,
 		"SLP057": false,
 		"SLP058": false,
@@ -66,7 +62,6 @@ func TestDefault_RegistersAllV001Rules(t *testing.T) {
 		"SLP062": false,
 		"SLP063": false,
 		"SLP064": false,
-		"SLP065": false,
 		"SLP066": false,
 		"SLP067": false,
 		"SLP068": false,
@@ -104,13 +99,11 @@ func TestDefault_RegistersAllV001Rules(t *testing.T) {
 		"SLP111": false,
 		"SLP112": false,
 		"SLP113": false,
-		"SLP114": false,
 		"SLP115": false,
 		"SLP116": false,
 		"SLP117": false,
 		"SLP118": false,
 		"SLP119": false,
-		"SLP120": false,
 		"SLP121": false,
 		"SLP122": false,
 		"SLP123": false,
@@ -142,6 +135,19 @@ func TestDefault_RegistersAllV001Rules(t *testing.T) {
 		"SLP207": false,
 		"SLP208": false,
 		"SLP209": false,
+		"SLP215": false,
+		"SLP216": false,
+		"SLP217": false,
+		"SLP218": false,
+		"SLP219": false,
+		"SLP220": false,
+		"SLP221": false,
+		"SLP222": false,
+		"SLP223": false,
+		"SLP224": false,
+		"SLP225": false,
+		"SLP226": false,
+		"SLP227": false,
 	}
 	for _, rule := range r.All() {
 		if _, ok := want[rule.ID()]; ok {
@@ -158,8 +164,8 @@ func TestDefault_RegistersAllV001Rules(t *testing.T) {
 func TestDefault_NoExtraRules(t *testing.T) {
 	r := Default()
 
-	// Includes SLP202-SLP205, SLP207, the P3 rules SLP151, SLP152, new precision rules SLP155-159, SLP035 split rules SLP160-162, reviewer gap rules SLP210-214, reviewer gap closure v2 rules SLP215-218, and reviewer gap closure v3 rules SLP219-222.
-	wantCount := 164
+	// Includes SLP202-SLP205, SLP207, the P3 rules SLP151, SLP152, new precision rules SLP155-159, SLP035 split rules SLP160-162, reviewer gap rules SLP210-214, reviewer gap closure v2 rules SLP215-218, reviewer gap closure v3 rules SLP219-222, and v4 rules SLP223-227.
+	wantCount := 162
 	if got := len(r.All()); got != wantCount {
 		t.Errorf("Default registry has %d rules, want %d", got, wantCount)
 	}
@@ -177,8 +183,8 @@ func TestDefault_NoExtraRules(t *testing.T) {
 		"SLP101", "SLP102", "SLP103", "SLP104",
 		"SLP106", "SLP107", "SLP108", "SLP109", "SLP110",
 		"SLP111", "SLP112",
-		"SLP113", "SLP114", "SLP115", "SLP116", "SLP117",
-		"SLP118", "SLP119", "SLP120",
+		"SLP113", "SLP115", "SLP116", "SLP117",
+		"SLP118", "SLP119",
 		"SLP121", "SLP122", "SLP123", "SLP124", "SLP125",
 		"SLP126", "SLP127",
 		"SLP128", "SLP129", "SLP130", "SLP131", "SLP132",
@@ -197,6 +203,19 @@ func TestDefault_NoExtraRules(t *testing.T) {
 		"SLP207",
 		"SLP208",
 		"SLP209",
+		"SLP215",
+		"SLP216",
+		"SLP217",
+		"SLP218",
+		"SLP219",
+		"SLP220",
+		"SLP221",
+		"SLP222",
+		"SLP223",
+		"SLP224",
+		"SLP225",
+		"SLP226",
+		"SLP227",
 	}
 	for _, id := range newRules {
 		if !ruleIDs[id] {

pkg/rules/slp043.go

@@ -1,3 +1,5 @@
+//go:build ignore_retired
+
 package rules
 
 import (

pkg/rules/slp050.go

@@ -1,3 +1,5 @@
+//go:build ignore_retired
+
 package rules
 
 import (

pkg/rules/slp050_test.go

@@ -1,3 +1,5 @@
+//go:build ignore_retired
+
 package rules
 
 import (

pkg/rules/slp055.go

@@ -1,3 +1,5 @@
+//go:build ignore_retired
+
 package rules
 
 import (

pkg/rules/slp055_test.go

@@ -1,3 +1,5 @@
+//go:build ignore_retired
+
 package rules
 
 import (