Add Vitest for testing and implement initial API tests

- Updated package.json to include Vitest as a dev dependency.
- Created api.test.js to add tests for the API, including checks for OS name, rule validation, Java API, manifest handling, and miscellaneous functions.
- Ensured tests cover both defined methods and expected behaviors.

Author: StoppedwummSites

.gitignore

@@ -9,4 +9,5 @@ java-runtime
 .DS_Store
 dist
 build
-__pycache__
+__pycache__
+test.txt

api.test.js

@@ -0,0 +1,66 @@
+// windows only test
+import index from "./index.js"
+import * as java from "./java.js"
+import { describe, it, expect } from "vitest"
+import fs from "fs/promises"
+
+describe("API exists", () => {
+    it("Should be defined", () => {
+        expect(index).toBeDefined()
+    })
+})
+
+describe("API methods", () => {
+    it("Can get OS name", () => {
+        expect(index.getOSName()).toBeDefined()
+        expect(index.getOSName()).eq("windows")
+    })
+    it("Can check rules", () => {
+        expect(index.checkRule({
+            "action": "allow",
+            "os": {
+                "name": "osx"
+            }
+        })).eq(false)
+        expect(index.checkRule({
+            "action": "allow",
+            "os": {
+                "name": "linux"
+            }
+        })).eq(false)
+        expect(index.checkRule({
+            "action": "allow",
+            "os": {
+                "name": "windows"
+            }
+        })).eq(true)
+    })
+})
+
+describe("Java API", () => {
+    it("Should be defined", () => {
+        expect(java.downloadJava).toBeDefined()
+        expect(java.downloadJava).toBeTypeOf("function")
+    })
+})
+
+describe("Can handle manifest", () => {
+    it("Should be defined", async () => {
+        expect(await index.loadManifest("neoforge-21.1.162.json")).toBeDefined()
+    })
+    it("Should merge Manifests", async () => {
+        expect(await index.mergeManifests(await index.loadManifest("neoforge-21.1.162.json"), await index.loadManifest("1.21.1.json"))).toBeDefined()
+        expect(await index.mergeManifests(await index.loadManifest("neoforge-21.1.162.json"), await index.loadManifest("1.21.1.json"))).toBeTypeOf("object")
+    })
+})
+
+describe("Misc functions", () => {
+    it("Should be defined", async () => {
+        expect(index.downloadFile).toBeDefined()
+        await fs.rm("test.txt", { force: true })
+        const download = await index.downloadFile("https://example.com", "test.txt")
+        expect(download).toBeDefined()
+        expect(download).toBeTypeOf("boolean")
+        expect(download).eq(true)
+    })
+})

index.js

@@ -823,8 +823,24 @@ async function main() {
 
 } // End of main function
 
-main().catch(error => {
-    console.error("\n--- An error occurred during setup or launch ---");
-    console.error(error);
-    process.exit(1);
-});
+const entryPointScript = process.argv[1].split(path.sep).pop();
+if (entryPointScript === __filename || entryPointScript === __dirname.split(path.sep).pop()) {
+    main().catch(error => {
+        console.error("\n--- An error occurred during setup or launch ---");
+        console.error(error);
+        process.exit(1);
+    });
+}
+
+export default {
+    downloadFile,
+    extractNatives,
+    getOSName,
+    getArchName,
+    checkRule,
+    checkItemRules,
+    ensureLauncherProfiles,
+    loadManifest,
+    mergeManifests,
+    main
+}