Add dotnet-version: latest support with dotnet-channel input (#730)

* feat: add dotnet-version: latest keyword with dotnet-channel support (#497)

* restore test-proxy container image

* update e2e-tests.yml and documentation

* fix(tests): correct release-type and support-phase values in latest-version test mocks

__tests__/latest-version.test.ts

@@ -0,0 +1,223 @@
+import {DotnetVersionResolver} from '../src/installer';
+import * as hc from '@actions/http-client';
+import * as core from '@actions/core';
+
+// Mock http-client
+jest.mock('@actions/http-client');
+
+describe('DotnetVersionResolver with latest', () => {
+  let getJsonMock: jest.Mock;
+  let warningSpy: jest.SpyInstance;
+
+  beforeEach(() => {
+    getJsonMock = jest.fn();
+    (hc.HttpClient as any).mockImplementation(() => {
+      return {
+        getJson: getJsonMock
+      };
+    });
+    warningSpy = jest.spyOn(core, 'warning').mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    jest.restoreAllMocks();
+  });
+
+  const mockReleases = {
+    'releases-index': [
+      {
+        'channel-version': '10.0',
+        'support-phase': 'preview',
+        'release-type': 'lts'
+      },
+      {
+        'channel-version': '9.0',
+        'support-phase': 'active',
+        'release-type': 'sts'
+      },
+      {
+        'channel-version': '8.0',
+        'support-phase': 'active',
+        'release-type': 'lts'
+      },
+      {
+        'channel-version': '7.0',
+        'support-phase': 'eol',
+        'release-type': 'sts'
+      }
+    ]
+  };
+
+  it('should resolve "latest" to highest stable version by default', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('latest');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('9.0');
+    expect(version.type.toLowerCase()).toContain('channel');
+    expect(version.qualityFlag).toBe(true);
+  });
+
+  it('should resolve "LATEST" (uppercase) to highest stable version', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('LATEST');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('9.0');
+    expect(version.type.toLowerCase()).toContain('channel');
+    expect(version.qualityFlag).toBe(true);
+  });
+
+  it('should resolve "latest" to highest preview version if quality is preview', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('latest', 'preview');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('10.0');
+  });
+
+  it('should resolve "latest" with channel filter LTS', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('latest', '', 'LTS');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('8.0');
+  });
+
+  it('should resolve "latest" with channel filter STS', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('latest', '', 'STS');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('9.0');
+  });
+
+  it('should resolve "latest" with channel filter STS and preview quality', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('latest', 'preview', 'STS');
+    const version = await resolver.createDotnetVersion();
+
+    // preview quality includes all support-phases; STS filter → 9.0 (active, sts)
+    expect(version.value).toBe('9.0');
+  });
+
+  it('should warn if channel is provided but version is not latest', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('8.0', '', 'LTS');
+    await resolver.createDotnetVersion();
+
+    expect(warningSpy).toHaveBeenCalledWith(
+      `The 'dotnet-channel' input is only supported when 'dotnet-version' is set to 'latest'.`
+    );
+  });
+
+  it('should throw when releases-index API returns empty active releases', async () => {
+    const emptyReleases = {
+      'releases-index': [
+        {
+          'channel-version': '7.0',
+          'support-phase': 'eol',
+          'release-type': 'sts'
+        }
+      ]
+    };
+    getJsonMock.mockResolvedValue({result: emptyReleases});
+
+    const resolver = new DotnetVersionResolver('latest');
+
+    await expect(resolver.createDotnetVersion()).rejects.toThrow(
+      /Could not find any active releases/
+    );
+  });
+
+  it('should throw when releases-index response has unexpected format', async () => {
+    getJsonMock.mockResolvedValue({result: {}});
+
+    const resolver = new DotnetVersionResolver('latest');
+
+    await expect(resolver.createDotnetVersion()).rejects.toThrow(
+      /Unexpected response format/
+    );
+  });
+
+  it('should throw when releases-index response is null', async () => {
+    getJsonMock.mockResolvedValue({result: null});
+
+    const resolver = new DotnetVersionResolver('latest');
+
+    await expect(resolver.createDotnetVersion()).rejects.toThrow(
+      /Unexpected response format/
+    );
+  });
+
+  it('should resolve "latest" with ga quality same as default (no previews)', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('latest', 'ga');
+    const version = await resolver.createDotnetVersion();
+
+    // ga should behave like no quality — skip preview (10.0), pick 9.0
+    expect(version.value).toBe('9.0');
+  });
+
+  it('should resolve "latest" with LTS channel and daily quality', async () => {
+    getJsonMock.mockResolvedValue({result: mockReleases});
+
+    const resolver = new DotnetVersionResolver('latest', 'daily', 'LTS');
+    const version = await resolver.createDotnetVersion();
+
+    // daily allows previews, LTS filter applies — 10.0 (preview, lts) is the highest LTS
+    expect(version.value).toBe('10.0');
+    expect(version.qualityFlag).toBe(true);
+  });
+
+  it('should resolve "latest" with A.B channel directly without API call', async () => {
+    const resolver = new DotnetVersionResolver('latest', '', '8.0');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('8.0');
+    expect(version.type.toLowerCase()).toContain('channel');
+    expect(version.qualityFlag).toBe(true);
+    // Should NOT call the API
+    expect(getJsonMock).not.toHaveBeenCalled();
+  });
+
+  it('should resolve "latest" with A.B.Cxx channel directly without API call', async () => {
+    const resolver = new DotnetVersionResolver('latest', '', '8.0.1xx');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('8.0.1xx');
+    expect(version.type.toLowerCase()).toContain('channel');
+    expect(version.qualityFlag).toBe(true);
+    // Should NOT call the API
+    expect(getJsonMock).not.toHaveBeenCalled();
+  });
+
+  it('should resolve "latest" with A.B channel for older version with qualityFlag false', async () => {
+    const resolver = new DotnetVersionResolver('latest', '', '3.1');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('3.1');
+    expect(version.type.toLowerCase()).toContain('channel');
+    // major 3 < 6 → qualityFlag false
+    expect(version.qualityFlag).toBe(false);
+    expect(getJsonMock).not.toHaveBeenCalled();
+  });
+
+  it('should resolve "latest" with A.B.Cxx channel and quality', async () => {
+    const resolver = new DotnetVersionResolver('latest', 'ga', '8.0.2xx');
+    const version = await resolver.createDotnetVersion();
+
+    expect(version.value).toBe('8.0.2xx');
+    expect(version.qualityFlag).toBe(true);
+    expect(getJsonMock).not.toHaveBeenCalled();
+  });
+});