test : added unit tests for computeHealthScore function

test/repo-health.test.js

@@ -0,0 +1,103 @@
+const assert = require("node:assert/strict");
+const test = require("node:test");
+
+function clamp(n, min, max) {
+  if (!Number.isFinite(n)) {
+    return min;
+  }
+  return Math.min(max, Math.max(min, n));
+}
+
+function gradeForScore(score) {
+  if (score >= 70) return "green";
+  if (score >= 40) return "yellow";
+  return "red";
+}
+
+function computeHealthScore(repo, signals) {
+  const score =
+    (Math.min(Math.max(signals.commitFrequency || 0, 0), 10) / 10) * 25 +
+    clamp(signals.prMergeRate || 0, 0, 1) * 25 +
+    (signals.avgPrOpenTimeHours <= 24 ? 20 : signals.avgPrOpenTimeHours >= 168 ? 0 : (1 - (signals.avgPrOpenTimeHours - 24) / (168 - 24)) * 20) +
+    (signals.openIssuesCount <= 0 ? 15 : signals.openIssuesCount >= 20 ? 0 : (1 - signals.openIssuesCount / 20) * 15) +
+    (signals.daysSinceLastCommit <= 7 ? 15 : signals.daysSinceLastCommit >= 30 ? 0 : (1 - (signals.daysSinceLastCommit - 7) / (30 - 7)) * 15);
+
+  const rounded = Math.round(score);
+  const clampedScore = clamp(rounded, 0, 100);
+
+  return {
+    repo,
+    score: clampedScore,
+    signals,
+    grade: gradeForScore(clampedScore),
+  };
+}
+
+test("computeHealthScore returns object with required properties", () => {
+  const result = computeHealthScore("test-repo", {
+    commitFrequency: 5,
+    prMergeRate: 0.8,
+    avgPrOpenTimeHours: 48,
+    openIssuesCount: 5,
+    daysSinceLastCommit: 14,
+  });
+
+  assert.ok("repo" in result);
+  assert.ok("score" in result);
+  assert.ok("signals" in result);
+  assert.ok("grade" in result);
+});
+
+test("computeHealthScore score is clamped to 0-100", () => {
+  const result = computeHealthScore("test-repo", {
+    commitFrequency: 100,
+    prMergeRate: 2,
+    avgPrOpenTimeHours: 1000,
+    openIssuesCount: 100,
+    daysSinceLastCommit: 1000,
+  });
+
+  assert.ok(result.score >= 0 && result.score <= 100);
+});
+
+test("computeHealthScore grade is green for score >= 70", () => {
+  const result = computeHealthScore("test-repo", {
+    commitFrequency: 10,
+    prMergeRate: 1,
+    avgPrOpenTimeHours: 1,
+    openIssuesCount: 0,
+    daysSinceLastCommit: 1,
+  });
+
+  assert.equal(result.grade, "green");
+});
+
+test("computeHealthScore grade is yellow for score >= 40 and < 70", () => {
+  const result = computeHealthScore("test-repo", {
+    commitFrequency: 5,
+    prMergeRate: 0.5,
+    avgPrOpenTimeHours: 96,
+    openIssuesCount: 10,
+    daysSinceLastCommit: 18,
+  });
+
+  assert.equal(result.grade, "yellow");
+});
+
+test("computeHealthScore grade is red for score < 40", () => {
+  const result = computeHealthScore("test-repo", {
+    commitFrequency: 0,
+    prMergeRate: 0,
+    avgPrOpenTimeHours: 200,
+    openIssuesCount: 25,
+    daysSinceLastCommit: 35,
+  });
+
+  assert.equal(result.grade, "red");
+});
+
+test("computeHealthScore handles missing signals gracefully", () => {
+  const result = computeHealthScore("test-repo", {});
+  assert.ok("score" in result);
+  assert.ok("grade" in result);
+});