add tests

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

jest.config.ts

@@ -0,0 +1,29 @@
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+
+const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'docker-setup-qemu-action-'));
+
+process.env = Object.assign({}, process.env, {
+  TEMP: tmpDir,
+  GITHUB_REPOSITORY: 'docker/setup-qemu-action',
+  RUNNER_TEMP: path.join(tmpDir, 'runner-temp'),
+  RUNNER_TOOL_CACHE: path.join(tmpDir, 'runner-tool-cache')
+}) as {
+  [key: string]: string;
+};
+
+module.exports = {
+  clearMocks: true,
+  moduleFileExtensions: ['js', 'ts'],
+  testMatch: ['**/*.test.ts'],
+  transform: {
+    '^.+\\.ts$': 'ts-jest'
+  },
+  moduleNameMapper: {
+    '^csv-parse/sync': '<rootDir>/node_modules/csv-parse/dist/cjs/sync.cjs'
+  },
+  collectCoverageFrom: ['src/**/{!(main.ts),}.ts'],
+  coveragePathIgnorePatterns: ['lib/', 'node_modules/', '__mocks__/', '__tests__/'],
+  verbose: true
+};