Add OpenTofu version file support (#59)

Signed-off-by: Brendon Smith <bws@bws.bio>

lib/test/setup-tofu.test.js

@@ -0,0 +1,176 @@
+// Node.js core
+const fs = require('fs').promises;
+const os = require('os');
+const path = require('path');
+
+// External
+const core = require('@actions/core');
+
+// First party
+const releases = require('../releases');
+const setup = require('../setup-tofu');
+
+// Mock dependencies
+jest.mock('@actions/core');
+jest.mock('@actions/io', () => ({
+  mv: jest.fn(),
+  cp: jest.fn(),
+  mkdirP: jest.fn()
+}));
+jest.mock('@actions/tool-cache', () => ({
+  downloadTool: jest.fn(),
+  extractZip: jest.fn()
+}));
+
+// Mock releases.js so setup-tofu.js can be tested in isolation
+jest.mock('../releases');
+
+// Set up global test fixtures
+const fallbackVersion = 'latest';
+let tempDir;
+let tempDirPath;
+let version = '1.10.5';
+let versionFile;
+let versionFileName = '.opentofu-version';
+
+describe('setup-tofu', () => {
+  beforeAll(async () => {
+    // Mock dependencies
+    const tc = require('@actions/tool-cache');
+    tc.downloadTool.mockResolvedValue('/mock/download/path');
+    tc.extractZip.mockResolvedValue('/mock/extract/path');
+
+    const io = require('@actions/io');
+    io.mv.mockResolvedValue();
+    io.cp.mockResolvedValue();
+    io.mkdirP.mockResolvedValue();
+
+    const mockRelease = {
+      getBuild: jest.fn().mockReturnValue({ url: 'mock-url' })
+    };
+    releases.getRelease.mockResolvedValue(mockRelease);
+
+    // Write version file to temporary directory
+    tempDirPath = path.join(os.tmpdir(), 'setup-tofu-');
+    tempDir = await fs.mkdtemp(tempDirPath);
+    versionFile = path.join(tempDir, versionFileName);
+    await fs.writeFile(versionFile, `${version}\n`);
+
+    // Mock action inputs to return default values
+    core.getInput.mockImplementation((name) => {
+      const defaults = {
+        tofu_version: fallbackVersion,
+        tofu_version_file: versionFile,
+        cli_config_credentials_hostname: '',
+        cli_config_credentials_token: '',
+        tofu_wrapper: 'true',
+        github_token: ''
+      };
+      return defaults[name] || '';
+    });
+
+    // Mock environment variables
+    process.env.GITHUB_TOKEN = 'mock-github-token';
+  });
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  afterAll(async () => {
+    delete process.env.GITHUB_TOKEN;
+  });
+
+  describe('tofu_version_file functionality', () => {
+    it('should read version from file when tofu_version_file is provided', async () => {
+      jest.spyOn(fs, 'readFile');
+
+      await setup();
+
+      expect(releases.getRelease).toHaveBeenCalledWith(
+        version, process.env.GITHUB_TOKEN
+      );
+
+      expect(fs.readFile).toHaveBeenCalled();
+    });
+
+    it('should handle empty version file gracefully', async () => {
+      jest.spyOn(fs, 'readFile');
+
+      version = ' ';
+      versionFileName = '.opentofu-version-empty';
+      versionFile = path.join(tempDir, versionFileName);
+      await fs.writeFile(versionFile, `${version}\n`);
+
+      core.getInput.mockImplementation((name) => {
+        if (name === 'tofu_version_file') {
+          return versionFile;
+        }
+        if (name === 'tofu_version') {
+          return fallbackVersion;
+        }
+        return '';
+      });
+
+      await setup();
+
+      expect(releases.getRelease).toHaveBeenCalledWith(
+        fallbackVersion, process.env.GITHUB_TOKEN
+      );
+
+      expect(core.warning).toHaveBeenCalledWith(
+        expect.stringContaining(`Version file ${versionFile} is empty`)
+      );
+
+      expect(fs.readFile).toHaveBeenCalled();
+    });
+
+    it('should handle file read errors gracefully', async () => {
+      jest.spyOn(fs, 'readFile');
+
+      versionFileName = '.opentofu-version-file-does-not-exist';
+      versionFile = path.join(tempDir, versionFileName);
+
+      core.getInput.mockImplementation((name) => {
+        if (name === 'tofu_version_file') {
+          return versionFile;
+        }
+        if (name === 'tofu_version') {
+          return fallbackVersion;
+        }
+        return '';
+      });
+
+      await setup();
+
+      expect(releases.getRelease).toHaveBeenCalledWith(
+        fallbackVersion, process.env.GITHUB_TOKEN
+      );
+
+      expect(core.warning).toHaveBeenCalledWith(
+        expect.stringContaining(`Failed to read version from file ${versionFile}`)
+      );
+
+      expect(fs.readFile).toHaveBeenCalled();
+    });
+
+    it('should not read file when tofu_version_file is not provided', async () => {
+      jest.spyOn(fs, 'readFile');
+
+      core.getInput.mockImplementation((name) => {
+        if (name === 'tofu_version') {
+          return fallbackVersion;
+        }
+        return '';
+      });
+
+      await setup();
+
+      expect(releases.getRelease).toHaveBeenCalledWith(
+        fallbackVersion, process.env.GITHUB_TOKEN
+      );
+
+      expect(fs.readFile).not.toHaveBeenCalled();
+    });
+  });
+});