tech-debt(unic-pr-review): regression fixture for dedupe-ordering catch (PR #5612)

apps/claude-code/unic-pr-review/tests/dedupe-ordering-regression.test.mjs

@@ -0,0 +1,121 @@
+// @ts-check
+// SPDX-License-Identifier: LGPL-3.0-or-later
+// Copyright © 2026 Unic
+
+/**
+ * Regression / eval fixture: dedupe-ordering catch (PR #5612)
+ *
+ * Parity guard: unic-pr-review correctly surfaced this pattern at Minor
+ * severity; pr-review v1.4.0 missed it entirely (false negative). This
+ * fixture pins the pattern and the expected quality bar so regressions are
+ * caught by CI as the plugin evolves.
+ *
+ * Background: AnalyticsTracker.tsx in PR #5612 contained an unconditional
+ * `lastFiredPathRef.current = null` at line 38, placed BEFORE the `cancelled`
+ * early-return guard at line 46. On an SSP-redirect-back-to-same-page (e.g.
+ * logo click while already on the landing page) the dedupe key is wiped and
+ * the destination `routeChangeComplete` handler re-fires a duplicate
+ * `page_view` for the same URL.
+ *
+ * unic-pr-review graded this Minor (confidence ~70) — correct, low-frequency
+ * path. pr-review v1.4.0 produced a false negative on the same diff.
+ */
+
+import assert from 'node:assert/strict'
+import { describe, it } from 'node:test'
+import { parseFinding } from '../scripts/lib/finding-validator.mjs'
+import { bucketBySeverity } from '../scripts/lib/severity-bucketer.mjs'
+
+/**
+ * Canonical diff encoding the dedupe-ordering pattern from PR #5612.
+ *
+ * The pattern: an unconditional ref/state reset is placed BEFORE an
+ * early-return guard, so on a same-key re-entry the dedupe key is already
+ * wiped when the guard is checked, allowing a duplicate emission.
+ *
+ * AnalyticsTracker.tsx (simplified, structure preserved):
+ *
+ *   38:  lastFiredPathRef.current = null   // ← unconditional reset
+ *   ...
+ *   46:  if (cancelled) return             // ← guard is TOO LATE
+ *   47:  if (url === lastFiredPathRef.current) return
+ *   48:  lastFiredPathRef.current = url
+ *   49:  trackPageView(url)
+ */
+const DEDUPE_ORDERING_DIFF = `\
++  useEffect(() => {
+     let cancelled = false
++    lastFiredPathRef.current = null
+
+     router.events.on('routeChangeComplete', (url) => {
+       if (cancelled) return
+       if (url === lastFiredPathRef.current) return
+       lastFiredPathRef.current = url
+       trackPageView(url)
+     })
+
+     return () => {
+       cancelled = true
+     }
+   }, [router])
+`
+
+/**
+ * Reference finding: what the code-reviewer MUST surface for this pattern.
+ *
+ * Confidence 70 is representative of the Minor band (60–79 per ADR-0002).
+ * This object is the eval ground-truth. parseFinding must accept it and derive
+ * severity 'minor'. If the thresholds or validator shape change in a way that
+ * breaks this finding, the regression fixture will fail.
+ *
+ * Note: REFERENCE_FINDING is the expected output shape for this pattern. It is
+ * not derived from DEDUPE_ORDERING_DIFF by any runtime logic in this file —
+ * the fixture validates the validator, not the detector.
+ */
+const REFERENCE_FINDING = {
+	confidence: 70,
+	filePath: 'src/analytics/AnalyticsTracker.tsx',
+	startLine: 38,
+	title: 'Dedupe-ref reset before early-return guard allows duplicate page_view emission',
+	body:
+		'`lastFiredPathRef.current = null` runs unconditionally before the `cancelled` guard.' +
+		' On an SSP-redirect-back-to-same-page the dedupe key is wiped, so the destination' +
+		' `routeChangeComplete` handler re-fires a duplicate `page_view` for the same URL.',
+	suggestion:
+		'Move the reset into the cleanup function after `cancelled = true`, so it only fires on unmount—not on every render cycle.',
+}
+
+describe('dedupe-ordering regression fixture (PR #5612 parity guard)', () => {
+	it('fixture contains the unconditional ref reset before the guard', () => {
+		const resetIdx = DEDUPE_ORDERING_DIFF.indexOf('lastFiredPathRef.current = null')
+		const guardIdx = DEDUPE_ORDERING_DIFF.indexOf('if (cancelled) return')
+		assert.ok(resetIdx !== -1, 'fixture must contain the unconditional ref reset')
+		assert.ok(guardIdx !== -1, 'fixture must contain the early-return guard')
+		assert.ok(resetIdx < guardIdx, 'reset must appear BEFORE the guard in the diff')
+	})
+
+	it('reference finding confidence (70) falls in the Minor band (60–79)', () => {
+		assert.equal(bucketBySeverity(REFERENCE_FINDING.confidence), 'minor')
+	})
+
+	it('parseFinding accepts the reference finding and derives severity minor', () => {
+		const result = parseFinding(REFERENCE_FINDING)
+		assert.ok(result !== null, 'finding must not be dropped (confidence >= 60)')
+		assert.equal(result.severity, 'minor')
+		assert.equal(result.confidence, 70)
+	})
+
+	it('reference finding title names the ordering defect', () => {
+		assert.ok(
+			/dedupe|duplicate|reset|guard/i.test(REFERENCE_FINDING.title),
+			'title must reference the ordering/dedupe issue'
+		)
+	})
+
+	it('reference finding body mentions the duplicate emission consequence', () => {
+		assert.ok(
+			/duplicate|re-fires?|emiss/i.test(REFERENCE_FINDING.body),
+			'body must describe the duplicate-emission consequence'
+		)
+	})
+})