test : added unit tests for scoreOpenIssuesCount function

test/repo-health.test.js

@@ -0,0 +1,50 @@
+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 scoreOpenIssuesCount(openIssues) {
+  if (openIssues <= 0) return 15;
+  if (openIssues >= 20) return 0;
+  const normalized = 1 - openIssues / 20;
+  return clamp(normalized, 0, 1) * 15;
+}
+
+test("scoreOpenIssuesCount returns 15 for openIssues <= 0", () => {
+  assert.equal(scoreOpenIssuesCount(0), 15);
+  assert.equal(scoreOpenIssuesCount(-1), 15);
+  assert.equal(scoreOpenIssuesCount(-10), 15);
+});
+
+test("scoreOpenIssuesCount returns 0 for openIssues >= 20", () => {
+  assert.equal(scoreOpenIssuesCount(20), 0);
+  assert.equal(scoreOpenIssuesCount(25), 0);
+  assert.equal(scoreOpenIssuesCount(100), 0);
+});
+
+test("scoreOpenIssuesCount scales linearly between 0 and 20", () => {
+  const midPoint = scoreOpenIssuesCount(10);
+  assert.ok(midPoint > 0 && midPoint < 15);
+  assert.equal(scoreOpenIssuesCount(10), 7.5);
+});
+
+test("scoreOpenIssuesCount handles boundary at 0 issues", () => {
+  assert.equal(scoreOpenIssuesCount(0), 15);
+});
+
+test("scoreOpenIssuesCount handles boundary at 20 issues", () => {
+  assert.equal(scoreOpenIssuesCount(20), 0);
+});
+
+test("scoreOpenIssuesCount handles NaN", () => {
+  assert.equal(scoreOpenIssuesCount(NaN), 0);
+});
+
+test("scoreOpenIssuesCount handles infinity", () => {
+  assert.equal(scoreOpenIssuesCount(Infinity), 0);
+});