Deprecate legacy Adopt distributions in v5

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

Copilot-Session: 0cd196f2-1044-4d33-96bb-8e794a00b03c

__tests__/distributors/distribution-factory.test.ts

@@ -0,0 +1,51 @@
+import * as core from '@actions/core';
+import {
+  AdoptDistribution,
+  AdoptImplementation
+} from '../../src/distributions/adopt/installer';
+import {JavaInstallerOptions} from '../../src/distributions/base-models';
+import {getJavaDistribution} from '../../src/distributions/distribution-factory';
+
+describe('getJavaDistribution', () => {
+  const installerOptions: JavaInstallerOptions = {
+    version: '11',
+    architecture: 'x64',
+    packageType: 'jdk',
+    checkLatest: false
+  };
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  it.each([
+    ['adopt', AdoptImplementation.Hotspot, 'temurin'],
+    ['adopt-hotspot', AdoptImplementation.Hotspot, 'temurin'],
+    ['adopt-openj9', AdoptImplementation.OpenJ9, 'semeru']
+  ])(
+    'warns that %s is deprecated while preserving its installer',
+    (
+      distributionName: string,
+      implementation: AdoptImplementation,
+      replacement: string
+    ) => {
+      const warningSpy = jest
+        .spyOn(core, 'warning')
+        .mockImplementation(() => {});
+
+      const distribution = getJavaDistribution(
+        distributionName,
+        installerOptions
+      );
+
+      expect(distribution).toBeInstanceOf(AdoptDistribution);
+      if (!(distribution instanceof AdoptDistribution)) {
+        throw new Error(`Expected an Adopt installer for ${distributionName}`);
+      }
+      expect(distribution['jvmImpl']).toBe(implementation);
+      expect(warningSpy).toHaveBeenCalledWith(
+        `The '${distributionName}' legacy AdoptOpenJDK distribution is deprecated and will be removed in setup-java v6. Please migrate to the '${replacement}' distribution.`
+      );
+    }
+  );
+});