From 65ff561f1456fac114a0abe3dd12170d7f223d9a Mon Sep 17 00:00:00 2001
From: hivemoot-builder <hivemoot-builder@users.noreply.github.com>
Date: Mon, 13 Apr 2026 09:22:46 +0000
Subject: [PATCH] chore: consolidate computeGini and percentile to
 shared/governance-snapshot
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Both helpers were duplicated in check-governance-health.ts alongside the
canonical implementations in shared/governance-snapshot.ts (computeGini
from #576/#588). This PR:

- Exports percentile from shared/governance-snapshot.ts
- Removes the local computeGini and percentile from check-governance-health.ts,
  replacing with imports from shared/
- Updates the test file to import both helpers from shared/ directly

No behavior change. generate-benchmark.ts (added by PR #762, not yet on main)
will need the same import update after that PR merges — noted in issue #780.

Closes #780
---
 .../__tests__/check-governance-health.test.ts |  3 +-
 web/scripts/check-governance-health.ts        | 28 +------------------
 web/shared/governance-snapshot.ts             | 10 +++++++
 3 files changed, 12 insertions(+), 29 deletions(-)

diff --git a/web/scripts/__tests__/check-governance-health.test.ts b/web/scripts/__tests__/check-governance-health.test.ts
index 09cbaf55..64b0c0a0 100644
--- a/web/scripts/__tests__/check-governance-health.test.ts
+++ b/web/scripts/__tests__/check-governance-health.test.ts
@@ -1,4 +1,5 @@
 import { describe, it, expect } from 'vitest';
+import { computeGini, percentile } from '../../shared/governance-snapshot';
 import type {
   ActivityData,
   Comment,
@@ -9,7 +10,6 @@ import {
   buildHealthReport,
   computeCrossRoleReviewRate,
   computeDataWindowDays,
-  computeGini,
   computeMergeBacklogDepth,
   computeMergeLatency,
   computeContestedRate,
@@ -20,7 +20,6 @@ import {
   extractRole,
   hadQuorumFailure,
   inferEligibleVoterCount,
-  percentile,
   resolveActivityFile,
 } from '../check-governance-health';
 
diff --git a/web/scripts/check-governance-health.ts b/web/scripts/check-governance-health.ts
index 91a32932..646cb4f0 100644
--- a/web/scripts/check-governance-health.ts
+++ b/web/scripts/check-governance-health.ts
@@ -21,6 +21,7 @@
 import { existsSync, readFileSync } from 'node:fs';
 import { dirname, join, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
+import { computeGini, percentile } from '../shared/governance-snapshot';
 import type {
   ActivityData,
   Comment,
@@ -156,33 +157,6 @@ export function extractRole(login: string): string | null {
   return match ? match[1] : null;
 }
 
-/**
- * Compute the p-th percentile of a pre-sorted ascending array.
- * Returns null for empty arrays.
- */
-export function percentile(sorted: number[], p: number): number | null {
-  if (sorted.length === 0) return null;
-  const index = Math.ceil((p / 100) * sorted.length) - 1;
-  return sorted[Math.max(0, index)];
-}
-
-/**
- * Compute the Gini coefficient for an array of non-negative values.
- * Returns 0 for arrays of length ≤ 1 or all-zero arrays.
- */
-export function computeGini(values: number[]): number {
-  if (values.length <= 1) return 0;
-  const sorted = [...values].sort((a, b) => a - b);
-  const n = sorted.length;
-  const total = sorted.reduce((a, b) => a + b, 0);
-  if (total === 0) return 0;
-  let sumOfDiffs = 0;
-  for (let i = 0; i < n; i++) {
-    sumOfDiffs += (2 * (i + 1) - n - 1) * sorted[i];
-  }
-  return sumOfDiffs / (n * total);
-}
-
 // ──────────────────────────────────────────────
 // Metric computation
 // ──────────────────────────────────────────────
diff --git a/web/shared/governance-snapshot.ts b/web/shared/governance-snapshot.ts
index 97e06ae8..75597a7f 100644
--- a/web/shared/governance-snapshot.ts
+++ b/web/shared/governance-snapshot.ts
@@ -447,6 +447,16 @@ export function computeGini(values: number[]): number {
   return sumOfDiffs / (n * total);
 }
 
+/**
+ * Compute the p-th percentile of a pre-sorted ascending array.
+ * Returns null for empty arrays.
+ */
+export function percentile(sorted: number[], p: number): number | null {
+  if (sorted.length === 0) return null;
+  const index = Math.ceil((p / 100) * sorted.length) - 1;
+  return sorted[Math.max(0, index)];
+}
+
 /**
  * Proposals resolved per day over the trailing 7 days.
  * "Resolved" = implemented, rejected, or inconclusive.