src/test/java/com/google/devtools/build/lib/sandbox/SandboxModuleTest.java

// Copyright 2026 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.devtools.build.lib.sandbox;

import static com.google.common.truth.Truth.assertThat;

import com.google.devtools.build.lib.testutil.Scratch;
import com.google.devtools.build.lib.vfs.DigestHashFunction;
import com.google.devtools.build.lib.vfs.FileSystem;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.build.lib.vfs.inmemoryfs.InMemoryFileSystem;
import java.io.IOException;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests for {@link SandboxModule}. */
@RunWith(JUnit4.class)
public final class SandboxModuleTest {

  private Scratch scratch;
  private Path sandboxBase;

  @Before
  public void setUp() throws Exception {
    scratch = new Scratch();
    sandboxBase = scratch.dir("/sandbox_base");
  }

  @Test
  public void checkSandboxBaseTopOnlyContainsPersistentDirs_persistentDirsSuccess()
      throws Exception {
    scratch.dir("/sandbox_base/_moved_trash_dir");
    scratch.dir("/sandbox_base/sandbox_stash");
    scratch.file("/sandbox_base/.DS_Store");

    SandboxModule.checkSandboxBaseTopOnlyContainsPersistentDirs(sandboxBase);
  }

  @Test
  public void
      checkSandboxBaseTopOnlyContainsPersistentDirs_withUnexpectedDirs_logsWarningWithoutCrashing()
          throws Exception {
    scratch.dir("/sandbox_base/_moved_trash_dir");
    scratch.dir("/sandbox_base/sandbox_stash");
    scratch.dir("/sandbox_base/linux-sandbox");

    // Must not throw IllegalStateException (issue #27892)
    SandboxModule.checkSandboxBaseTopOnlyContainsPersistentDirs(sandboxBase);
  }

  @Test
  public void checkSandboxBaseTopOnlyContainsPersistentDirs_withInaccessibleHelpers_cleansUp()
      throws Exception {
    Path helperDir = sandboxBase.getChild(SandboxHelpers.INACCESSIBLE_HELPER_DIR);
    helperDir.createDirectoryAndParents();
    helperDir.getChild("nested_file").createDirectoryAndParents();

    Path helperFile = sandboxBase.getChild(SandboxHelpers.INACCESSIBLE_HELPER_FILE);
    scratch.file(helperFile.getPathString(), "dummy content");

    SandboxModule.checkSandboxBaseTopOnlyContainsPersistentDirs(sandboxBase);

    assertThat(helperDir.exists()).isFalse();
    assertThat(helperFile.exists()).isFalse();
  }

  @Test
  public void cleanSandboxBaseTopOnlyContainsPersistentDirs_cleansUnexpectedDirsAndFiles()
      throws Exception {
    scratch.dir("/sandbox_base/_moved_trash_dir");
    scratch.dir("/sandbox_base/sandbox_stash");
    scratch.dir("/sandbox_base/linux-sandbox");
    scratch.file("/sandbox_base/stale_file.txt", "stale content");

    SandboxModule.cleanSandboxBaseTopOnlyContainsPersistentDirs(
        sandboxBase, new SynchronousTreeDeleter());

    assertThat(sandboxBase.getChild("_moved_trash_dir").exists()).isTrue();
    assertThat(sandboxBase.getChild("sandbox_stash").exists()).isTrue();
    assertThat(sandboxBase.getChild("linux-sandbox").exists()).isFalse();
    assertThat(sandboxBase.getChild("stale_file.txt").exists()).isFalse();

    SandboxModule.checkSandboxBaseTopOnlyContainsPersistentDirs(sandboxBase);
  }

  @Test
  public void cleanSandboxBaseOnFirstBuild_renameFails_fallsBackToSynchronousDeletion()
      throws Exception {
    FileSystem failingRenameFs =
        new InMemoryFileSystem(DigestHashFunction.SHA256) {
          @Override
          public void renameTo(PathFragment sourcePath, PathFragment targetPath)
              throws IOException {
            throw new IOException("Simulated overlayfs EXDEV on rename");
          }
        };
    Scratch failingScratch = new Scratch(failingRenameFs);
    Path failingSandboxBase = failingScratch.dir("/sandbox_base");
    Path trashBase = failingScratch.dir("/sandbox_base/_moved_trash_dir");
    failingScratch.file("/sandbox_base/_moved_trash_dir/stale_trash.txt", "stale");
    failingScratch.file("/sandbox_base/stale_sandbox.txt", "stale");

    SandboxModule sandboxModule = new SandboxModule();
    sandboxModule.treeDeleter = new AsynchronousTreeDeleter(trashBase);

    sandboxModule.cleanSandboxBaseOnFirstBuild(failingSandboxBase, trashBase, /* idleThreads= */ 4);

    assertThat(failingSandboxBase.exists()).isFalse();
    assertThat(sandboxModule.treeDeleter).isInstanceOf(AsynchronousTreeDeleter.class);
    sandboxModule.blazeShutdown();
  }
}