From a1bb6b791ce922714dda71f90fac18aaae44fa7b Mon Sep 17 00:00:00 2001
From: Naomi Carrigan <commits@nhcarrigan.com>
Date: Tue, 3 Feb 2026 19:07:14 -0800
Subject: [PATCH] feat: no unstable versions

---
 src/services/npmService.ts       |  7 ++++++
 test/services/npmService.spec.ts | 37 ++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/src/services/npmService.ts b/src/services/npmService.ts
index 614b4b9..5780d20 100644
--- a/src/services/npmService.ts
+++ b/src/services/npmService.ts
@@ -6,6 +6,7 @@
 
 import { Logger } from "@nhcarrigan/logger";
 import axios, { isAxiosError, type AxiosInstance } from "axios";
+import semver from "semver";
 import { config } from "../config.js";
 import type { NpmPackageInfo } from "../types/package.types.js";
 
@@ -164,6 +165,12 @@ class NpmService {
 
     const versions = Object.keys(packageInfo.versions);
     const matureVersions = versions.filter((version) => {
+      // Skip prerelease versions (e.g., 1.0.0-rc.1, 1.0.0-alpha, 1.0.0-beta.2)
+      const prereleaseComponents = semver.prerelease(version);
+      if (prereleaseComponents !== null && prereleaseComponents.length > 0) {
+        return false;
+      }
+
       const publishedAt = packageInfo.time[version];
       if (publishedAt === undefined) {
         return false;
diff --git a/test/services/npmService.spec.ts b/test/services/npmService.spec.ts
index 3ec9dcc..e5e70c5 100644
--- a/test/services/npmService.spec.ts
+++ b/test/services/npmService.spec.ts
@@ -429,4 +429,41 @@ describe("npmService", () => {
     const resultCustom = NpmService.getLatestMatureVersion(packageInfo, 3);
     expect(resultCustom).toBe("2.0.0");
   });
+
+  it("should skip prerelease versions like rc, alpha, beta", () => {
+    expect.assertions(1);
+    const oldDate = getDaysAgoIso(15);
+    const packageInfo = {
+      "dist-tags": { latest: "3.0.0-rc.1" },
+      "name":      "test-package",
+      "time":      {
+        "2.0.0":        oldDate,
+        "3.0.0-alpha":  oldDate,
+        "3.0.0-beta.1": oldDate,
+        "3.0.0-rc.1":   oldDate,
+      },
+      "versions": {
+        "2.0.0":        { version: "2.0.0" },
+        "3.0.0-alpha":  { version: "3.0.0-alpha" },
+        "3.0.0-beta.1": { version: "3.0.0-beta.1" },
+        "3.0.0-rc.1":   { version: "3.0.0-rc.1" },
+      },
+    };
+    // Should return 2.0.0 since all 3.0.0 versions are prereleases
+    const result = NpmService.getLatestMatureVersion(packageInfo);
+    expect(result).toBe("2.0.0");
+  });
+
+  it("should return null when only prerelease versions exist", () => {
+    expect.assertions(1);
+    const oldDate = getDaysAgoIso(15);
+    const packageInfo = {
+      "dist-tags": { latest: "1.0.0-rc.1" },
+      "name":      "test-package",
+      "time":      { "1.0.0-rc.1": oldDate },
+      "versions":  { "1.0.0-rc.1": { version: "1.0.0-rc.1" } },
+    };
+    const result = NpmService.getLatestMatureVersion(packageInfo);
+    expect(result).toBeNull();
+  });
 });