feat(enrichment): add revert-recurrence detector

.env.example

@@ -69,7 +69,7 @@ GITTENSORY_REVIEW_ENRICHMENT=false
 # blameLink,approvalIntegrity,ciCheckSignals,undocumentedExport,staleBranch,commitHygiene
 # pendingReviewRequests,testRatio,migrationSafety,looseRange,terminology,todoMarker,magicNumber
 # conflictMarker,debugLeftover,sizeSmell,floatingPromise,deepNesting,errorSwallow,unsafeAny,a11y
-# i18n,unusedExport,exhaustiveness,flakyTest,commitLint,apiBreak,deprecatedDep
+# i18n,unusedExport,exhaustiveness,flakyTest,commitLint,apiBreak,deprecatedDep,revertRecurrence
 #
 # Profile defaults:
 # fast: dependency,dependencyDiff,lockfileDrift,secret,license,installScript,heavyDependency
@@ -84,14 +84,14 @@ GITTENSORY_REVIEW_ENRICHMENT=false
 # commitHygiene,pendingReviewRequests,testRatio,migrationSafety,looseRange,terminology
 # todoMarker,magicNumber,conflictMarker,debugLeftover,sizeSmell,floatingPromise,deepNesting
 # errorSwallow,unsafeAny,a11y,i18n,unusedExport,exhaustiveness,flakyTest,commitLint,apiBreak
-# deprecatedDep
+# deprecatedDep,revertRecurrence
 # deep: dependency,dependencyDiff,lockfileDrift,secret,license,installScript,heavyDependency
 # hardcodedUrl,actionPin,eol,redos,provenance,codeowners,secretLog,assetWeight,typosquat
 # commitSignature,iacMisconfig,nativeBuild,history,docCommentDrift,duplication,churnHotspot
 # blameLink,approvalIntegrity,ciCheckSignals,undocumentedExport,staleBranch,commitHygiene
 # pendingReviewRequests,testRatio,migrationSafety,looseRange,terminology,todoMarker,magicNumber
 # conflictMarker,debugLeftover,sizeSmell,floatingPromise,deepNesting,errorSwallow,unsafeAny,a11y
-# i18n,unusedExport,exhaustiveness,flakyTest,commitLint,apiBreak,deprecatedDep
+# i18n,unusedExport,exhaustiveness,flakyTest,commitLint,apiBreak,deprecatedDep,revertRecurrence
 # END GENERATED REES ANALYZERS
 
 # Submitter-reputation spend control (internal-only): downgrades new/burst/low-rep

apps/gittensory-ui/src/lib/rees-analyzers.ts

@@ -1268,6 +1268,33 @@ export const REES_ANALYZERS = [
         "Conservative: only an exact match against the bundled list is flagged, so a package it does not name is never reported. Bounded by manifest, patch-line, and finding caps; fail-safe on absent patches or an aborted signal.",
     },
   },
+  {
+    name: "revertRecurrence",
+    title: "Revert recurrence",
+    category: "history",
+    cost: "github-heavy",
+    defaultEnabled: true,
+    profiles: ["balanced", "deep"],
+    requires: ["files", "github-token"],
+    limits: {
+      maxFilesProbed: 5,
+      commitsPerFile: 15,
+      maxRevertLookups: 10,
+      maxFindings: 25,
+    },
+    docs: {
+      summary:
+        "Flags a changed file where the PR re-introduces added lines in a region a prior revert commit removed — a signal it may be re-treading a path that was already reverted or hot-fixed out.",
+      looksAt:
+        "For each changed file's added line-ranges, the file's recent commit history and the patch of any revert commit in it, intersecting the reverted (removed) old-file line-ranges with this PR's added new-file line-ranges.",
+      reports:
+        "File, a re-introduced line, a short revert commit-SHA prefix, and the reverted PR number when the revert message names one — never file contents.",
+      network:
+        "Calls the GitHub commits API per probed file and the single-commit API per revert commit, both bounded by fixed fanout caps. Requires GitHub token forwarding for private repos.",
+      notes:
+        "Conservative: only a message-confirmed revert commit whose removed range overlaps an added range is reported (one finding per file); line-range overlap is a heuristic across history, and lockfiles/generated/binary paths are skipped. Fail-safe on missing token/invalid slug/fetch error or an aborted signal.",
+    },
+  },
 ] as const satisfies readonly ReesAnalyzerDoc[];
 
 export const REES_ANALYZER_NAMES = REES_ANALYZERS.map((analyzer) => analyzer.name);

review-enrichment/analyzer-metadata.json

@@ -1427,6 +1427,34 @@
         "network": "Pure local analyzer. No external network call; the curated list is bundled.",
         "notes": "Conservative: only an exact match against the bundled list is flagged, so a package it does not name is never reported. Bounded by manifest, patch-line, and finding caps; fail-safe on absent patches or an aborted signal."
       }
+    },
+    {
+      "name": "revertRecurrence",
+      "title": "Revert recurrence",
+      "category": "history",
+      "cost": "github-heavy",
+      "defaultEnabled": true,
+      "profiles": [
+        "balanced",
+        "deep"
+      ],
+      "requires": [
+        "files",
+        "github-token"
+      ],
+      "limits": {
+        "maxFilesProbed": 5,
+        "commitsPerFile": 15,
+        "maxRevertLookups": 10,
+        "maxFindings": 25
+      },
+      "docs": {
+        "summary": "Flags a changed file where the PR re-introduces added lines in a region a prior revert commit removed — a signal it may be re-treading a path that was already reverted or hot-fixed out.",
+        "looksAt": "For each changed file's added line-ranges, the file's recent commit history and the patch of any revert commit in it, intersecting the reverted (removed) old-file line-ranges with this PR's added new-file line-ranges.",
+        "reports": "File, a re-introduced line, a short revert commit-SHA prefix, and the reverted PR number when the revert message names one — never file contents.",
+        "network": "Calls the GitHub commits API per probed file and the single-commit API per revert commit, both bounded by fixed fanout caps. Requires GitHub token forwarding for private repos.",
+        "notes": "Conservative: only a message-confirmed revert commit whose removed range overlaps an added range is reported (one finding per file); line-range overlap is a heuristic across history, and lockfiles/generated/binary paths are skipped. Fail-safe on missing token/invalid slug/fetch error or an aborted signal."
+      }
     }
   ]
 }

review-enrichment/src/analyzers/registry.ts

@@ -49,6 +49,7 @@ import { scanExhaustivenessDrift } from "./exhaustiveness-drift.js";
 import { scanFlakyTest } from "./flaky-test.js";
 import { scanApiBreak } from "./api-break.js";
 import { scanDeprecatedDependencies } from "./deprecated-dep.js";
+import { scanRevertRecurrence } from "./revert-recurrence.js";
 import type {
   AnalyzerDescriptor,
   AnalyzerFn,
@@ -1446,6 +1447,48 @@ export const ANALYZER_DESCRIPTORS = [
     },
     run: (req, { signal }) => scanDeprecatedDependencies(req, signal),
   }),
+  descriptor({
+    name: "revertRecurrence",
+    title: "Revert recurrence",
+    category: "history",
+    cost: "github-heavy",
+    defaultEnabled: true,
+    requires: ["files", "github-token"],
+    limits: {
+      maxFilesProbed: 5,
+      commitsPerFile: 15,
+      maxRevertLookups: 10,
+      maxFindings: 25,
+    },
+    docs: {
+      summary:
+        "Flags a changed file where the PR re-introduces added lines in a region a prior revert commit removed — a signal it may be re-treading a path that was already reverted or hot-fixed out.",
+      looksAt:
+        "For each changed file's added line-ranges, the file's recent commit history and the patch of any revert commit in it, intersecting the reverted (removed) old-file line-ranges with this PR's added new-file line-ranges.",
+      reports:
+        "File, a re-introduced line, a short revert commit-SHA prefix, and the reverted PR number when the revert message names one — never file contents.",
+      network:
+        "Calls the GitHub commits API per probed file and the single-commit API per revert commit, both bounded by fixed fanout caps. Requires GitHub token forwarding for private repos.",
+      notes:
+        "Conservative: only a message-confirmed revert commit whose removed range overlaps an added range is reported (one finding per file); line-range overlap is a heuristic across history, and lockfiles/generated/binary paths are skipped. Fail-safe on missing token/invalid slug/fetch error or an aborted signal.",
+    },
+    render: (findings, helpers) => {
+      if (!findings.length) return [];
+      const lines = [
+        "### Revert recurrence (re-introduces code from a previously reverted region)",
+      ];
+      for (const item of findings) {
+        const pr =
+          item.revertedPr !== undefined ? ` (revert of #${item.revertedPr})` : "";
+        lines.push(
+          `- ${helpers.safeCodeSpan(`${item.file}:${item.line}`)} overlaps a region removed by revert commit ${helpers.safeCodeSpan(item.revertShaPrefix)}${pr}`,
+        );
+      }
+      return lines;
+    },
+    run: (req, { signal, analysis, diagnostics }) =>
+      scanRevertRecurrence(req, fetch, { signal, analysis, diagnostics }),
+  }),
 ] as const satisfies readonly AnyAnalyzerDescriptor[];
 
 export const ANALYZER_NAMES = ANALYZER_DESCRIPTORS.map(