Give latest+qualifier inputs (e.g. latest-ea) a targeted error

Inputs like 'latest-ea' had their '-ea' suffix stripped and fell through
to the generic SemVer validation, failing with a confusing "'latest' is
not valid SemVer" message even though 'latest' is supported. Add an
explicit guard so any 'latest*' value other than exactly 'latest' throws
a targeted error explaining that 'latest' resolves GA releases only and
cannot be combined with '-ea' or other qualifiers.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

__tests__/distributors/base-installer.test.ts

@@ -793,6 +793,17 @@ describe('normalizeVersion', () => {
       `The string '${version}' is not valid SemVer notation for a Java version. Please check README file for code snippets and more detailed information`
     );
   });
+
+  it.each(['latest-ea', 'latest.1', 'LATEST-EA', '  latest-ea  '])(
+    'normalizeVersion should throw a targeted error for latest combined with a qualifier (%s)',
+    version => {
+      expect(
+        DummyJavaBase.prototype.normalizeVersion.bind(null, version)
+      ).toThrow(
+        `The 'latest' alias resolves stable (GA) releases only and cannot be combined with '-ea' or other qualifiers (received '${version}'). Use 'latest' on its own, or specify a concrete version.`
+      );
+    }
+  );
 });
 
 describe('createVersionNotFoundError', () => {

dist/setup/index.js

@@ -131274,13 +131274,22 @@ class JavaBase {
         // Support the `latest` alias (case-insensitive), which floats to the newest
         // available stable/GA release. It is translated to the SemVer wildcard `x`
         // so the existing "newest satisfying version wins" resolution applies.
-        if (version.trim().toLowerCase() === 'latest') {
+        const normalized = version.trim().toLowerCase();
+        if (normalized === 'latest') {
             return {
                 version: 'x',
                 stable: true,
                 latest: true
             };
         }
+        // Reject `latest` combined with any qualifier (e.g. `latest-ea`). Such inputs
+        // would otherwise have their `-ea` suffix stripped and fall through to the
+        // generic SemVer check, which fails with a confusing "'latest' is not valid
+        // SemVer" message even though `latest` is a supported value. Fail early with a
+        // targeted explanation instead.
+        if (normalized.startsWith('latest')) {
+            throw new Error(`The 'latest' alias resolves stable (GA) releases only and cannot be combined with '-ea' or other qualifiers (received '${version}'). Use 'latest' on its own, or specify a concrete version.`);
+        }
         if (version.endsWith('-ea')) {
             version = version.replace(/-ea$/, '');
             stable = false;
@@ -132401,11 +132410,13 @@ class CorrettoDistribution extends JavaBase {
         // matches on an exact major version, so resolve it to the newest available
         // major from Corretto's own list.
         if (this.latest) {
-            const latestMajor = availableVersions
+            const majors = availableVersions
                 .map(item => parseInt(item.version, 10))
-                .filter(major => !Number.isNaN(major))
+                .filter(major => Number.isFinite(major) && major > 0);
-                .reduce((max, current) => (current > max ? current : max), 0);
+            if (majors.length === 0) {
-            version = latestMajor.toString();
+                throw new Error('Could not determine the latest available Corretto major version from remote metadata');
+            }
+            version = Math.max(...majors).toString();
         }
         if (version.includes('.')) {
             throw new Error('Only major versions are supported');

src/distributions/base-installer.ts

@@ -275,7 +275,8 @@ export abstract class JavaBase {
     // Support the `latest` alias (case-insensitive), which floats to the newest
     // available stable/GA release. It is translated to the SemVer wildcard `x`
     // so the existing "newest satisfying version wins" resolution applies.
-    if (version.trim().toLowerCase() === 'latest') {
+    const normalized = version.trim().toLowerCase();
+    if (normalized === 'latest') {
       return {
         version: 'x',
         stable: true,
@@ -283,6 +284,17 @@ export abstract class JavaBase {
       };
     }
 
+    // Reject `latest` combined with any qualifier (e.g. `latest-ea`). Such inputs
+    // would otherwise have their `-ea` suffix stripped and fall through to the
+    // generic SemVer check, which fails with a confusing "'latest' is not valid
+    // SemVer" message even though `latest` is a supported value. Fail early with a
+    // targeted explanation instead.
+    if (normalized.startsWith('latest')) {
+      throw new Error(
+        `The 'latest' alias resolves stable (GA) releases only and cannot be combined with '-ea' or other qualifiers (received '${version}'). Use 'latest' on its own, or specify a concrete version.`
+      );
+    }
+
     if (version.endsWith('-ea')) {
       version = version.replace(/-ea$/, '');
       stable = false;