Check if buildx available on runner

Use default buildx on runner

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

setup-buildx/__tests__/buildx.test.ts

@@ -0,0 +1,24 @@
+import fs = require('fs');
+import * as buildx from '../src/buildx';
+import * as path from 'path';
+import * as os from 'os';
+
+const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'setup-buildx-'));
+
+describe('buildx', () => {
+  it('is available', async () => {
+    expect(await buildx.isAvailable()).toBe(true);
+  }, 100000);
+
+  it('acquires v0.2.2 version of buildx', async () => {
+    const buildxBin = await buildx.install('v0.2.2', tmpDir);
+    console.log(buildxBin);
+    expect(fs.existsSync(buildxBin)).toBe(true);
+  }, 100000);
+
+  it('acquires latest version of buildx', async () => {
+    const buildxBin = await buildx.install('latest', tmpDir);
+    console.log(buildxBin);
+    expect(fs.existsSync(buildxBin)).toBe(true);
+  }, 100000);
+});