feat: add a function to fetch version manifest

src/core/index.ts

@@ -1 +1,2 @@
-export * as java from "./java"
+export * as java from "./java"
+export * as version from "./version"

src/core/version.ts

@@ -0,0 +1,24 @@
+import { fetchJson } from "../utils/fetch";
+import { Versions, Version } from "../utils/types";
+
+export async function getVersionManifest(versionString: string) {
+  const versions = await (
+    await fetchJson<Versions>(
+      "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json",
+    )
+  ).versions;
+
+  let versionManifestURL = "";
+  for (const v in versions) {
+    if (Object.prototype.hasOwnProperty.call(versions, v)) {
+      const version = versions[v];
+      if (version.id === versionString) {
+        versionManifestURL = version.url;
+      }
+    }
+  }
+
+  const versionManifest = await fetchJson<Version>(versionManifestURL);
+
+  return versionManifest;
+}

src/utils/types.ts

@@ -57,6 +57,73 @@ export type FilesList = {
       type: FileType;
     };
   };
-}
+};
 
-export type PoolFile = { url: string; path: string };
+export type PoolFile = { url: string; path: string };
+
+export type Versions = {
+  latest: { release: string; snapshot: string };
+  versions: {
+    id: string;
+    type: "snapshot" | "release" | "old_beta" | "old_alpha";
+    url: string;
+    time: string;
+    releaseTime: string;
+    sha1: string;
+    complianceLevel: number;
+  }[];
+};
+
+export type Version = {
+  arguments: {
+    game: string[];
+    jvm:
+      | {
+          rules: {
+            action: string;
+            os: { name?: string; version?: string; arch?: string };
+          }[];
+          value: string[] | string;
+        }
+      | string[];
+  };
+  assetIndex: {
+    id: string;
+    sha1: string;
+    size: number;
+    totalSize: number;
+    url: string;
+  };
+  assets: string;
+  complianceLevel: number;
+  downloads: {
+    client: File;
+    client_mappings: File;
+    server: File;
+    server_mappings: File;
+  };
+  id: string;
+  javaVersion: {
+    component: RuntimeComponent;
+    majorVersion: number;
+  };
+  libraries: {
+    downloads: {
+      artifacts: {
+        path: string;
+        sha1: string;
+        size: number;
+        url: string;
+      };
+      name: string;
+      rules: { action: string; os: { name: string } }[];
+    };
+  }[];
+  logging: {
+    client: {
+      argument: string;
+      file: { id: string; sha1: string; size: number; url: string };
+      type: string;
+    };
+  };
+};

tests/version.test.ts

@@ -0,0 +1,12 @@
+import { expect, test } from "vitest";
+import * as nlk from "../dist/index.js";
+import fs from "fs/promises";
+
+// ensure same formating
+const manifest = JSON.parse(await fs.readFile("./tests/1.21.8.json", { encoding: "utf-8" }));
+
+test("get 1.21.8 version manifest", async () => {
+  expect(
+    await nlk.core.version.getVersionManifest("1.21.8"),
+  ).toStrictEqual(manifest);
+});