fix: "show" cmd error for packages without stable versions

package.json

@@ -47,6 +47,7 @@
   },
   "dependencies": {
     "kolorist": "^1.8.0",
-    "node-stream-zip": "^1.15.0"
+    "node-stream-zip": "^1.15.0",
+    "semiver": "^1.1.0"
   }
 }

src/commands.ts

@@ -12,6 +12,7 @@ import {
 import { Bun, getPkgManager, PkgManagerName, YarnBerry } from "./pkg_manager";
 import { downloadDeno, getDenoDownloadUrl } from "./download";
 import { getNpmPackageInfo, getPackageMeta } from "./api";
+import semiver from "semiver";
 
 const NPMRC_FILE = ".npmrc";
 const BUNFIG_FILE = "bunfig.toml";
@@ -201,10 +202,23 @@ export async function showPackageInfo(raw: string) {
 
   const meta = await getPackageMeta(pkg);
   if (pkg.version === null) {
-    if (meta.latest === undefined) {
+    let latest = meta.latest;
+    if (latest === undefined) {
       throw new Error(`Missing latest version for ${pkg}`);
+    } else if (latest === null) {
+      // When no stable version is published: `latest === null`. We need to
+      // manually find the latest pre-release version
+      const versions = Object.keys(meta.versions);
+
+      if (versions.length === 0) {
+        throw new Error(`Could not find published version for ${pkg}`);
+      }
+
+      versions.sort(semiver);
+      pkg.version = versions[0];
+    } else {
+      pkg.version = latest;
     }
-    pkg.version = meta.latest!;
   }
 
   const versionCount = Object.keys(meta.versions).length;

test/commands.test.ts

@@ -788,4 +788,16 @@ describe("show", () => {
       process.cwd(),
     );
   });
+
+  it("should show package information for pre-release only packages", async () => {
+    const output = await runJsr(
+      ["show", "@fresh/update"],
+      process.cwd(),
+      undefined,
+      true,
+    );
+    const txt = kl.stripColors(output);
+    assert.ok(txt.includes("latest: -"));
+    assert.ok(txt.includes("npm tarball:"));
+  });
 });