Include non-directories in `DirectoryListingHelper::leafDirectoryEntr…

…ies` result.

`DirectoryListingHelper::leafDirectoryEntries` has a bug that it will only
include empty directories in the result. Fix the helper to include
non-directory entries and add unit tests covering that.

PiperOrigin-RevId: 376977471

src/main/java/com/google/devtools/build/lib/testing/common/DirectoryListingHelper.java

@@ -24,6 +24,11 @@ public final class DirectoryListingHelper {
 
   private DirectoryListingHelper() {}
 
+  /** Shorthand for {@link Dirent} of {@link Dirent.Type#FILE} type with a given name. */
+  public static Dirent file(String name) {
+    return new Dirent(name, Dirent.Type.FILE);
+  }
+
   /** Shorthand for {@link Dirent} of {@link Dirent.Type#DIRECTORY} type with a given name. */
   public static Dirent directory(String name) {
     return new Dirent(name, Dirent.Type.DIRECTORY);
@@ -52,16 +57,19 @@ private static void leafDirectoryEntriesInternal(
       Path path, String prefix, ImmutableList.Builder<Dirent> entries) throws IOException {
     boolean isEmpty = true;
     for (Dirent dirent : path.readdir(Symlinks.NOFOLLOW)) {
+      isEmpty = false;
+      String entryName = prefix.isEmpty() ? dirent.getName() : prefix + "/" + dirent.getName();
+
       if (dirent.getType() == Dirent.Type.DIRECTORY) {
-        leafDirectoryEntriesInternal(
-            path.getChild(dirent.getName()),
-            prefix.isEmpty() ? dirent.getName() : prefix + "/" + dirent.getName(),
-            entries);
+        leafDirectoryEntriesInternal(path.getChild(dirent.getName()), entryName, entries);
+        continue;
       }
-      isEmpty = false;
+
+      entries.add(new Dirent(entryName, dirent.getType()));
     }
 
-    if (isEmpty) {
+    // Skip adding the root if it's empty.
+    if (isEmpty && !prefix.isEmpty()) {
       entries.add(new Dirent(prefix, Dirent.Type.DIRECTORY));
     }
   }

src/test/java/com/google/devtools/build/lib/testing/common/BUILD

@@ -1,19 +1,31 @@
 load("@rules_java//java:defs.bzl", "java_test")
 
 package(
-    default_testonly = 1,
+    default_testonly = True,
     default_visibility = ["//src:__subpackages__"],
 )
 
 licenses(["notice"])
 
 filegroup(
     name = "srcs",
-    testonly = 0,
+    testonly = False,
     srcs = glob(["**"]),
     visibility = ["//src:__subpackages__"],
 )
 
+java_test(
+    name = "DirectoryListingHelperTest",
+    srcs = ["DirectoryListingHelperTest.java"],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib/testing/common:directory_listing_helper",
+        "//src/main/java/com/google/devtools/build/lib/vfs",
+        "//src/test/java/com/google/devtools/build/lib/testutil",
+        "//third_party:junit4",
+        "//third_party:truth",
+    ],
+)
+
 java_test(
     name = "FakeOptionsTest",
     srcs = ["FakeOptionsTest.java"],

src/test/java/com/google/devtools/build/lib/testing/common/DirectoryListingHelperTest.java

@@ -0,0 +1,89 @@
+// Copyright 2021 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.testing.common;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.devtools.build.lib.testing.common.DirectoryListingHelper.directory;
+import static com.google.devtools.build.lib.testing.common.DirectoryListingHelper.file;
+import static com.google.devtools.build.lib.testing.common.DirectoryListingHelper.leafDirectoryEntries;
+import static org.junit.Assert.assertThrows;
+
+import com.google.devtools.build.lib.testutil.Scratch;
+import com.google.devtools.build.lib.vfs.Path;
+import java.io.FileNotFoundException;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link com.google.devtools.build.lib.testing.common.DirectoryListingHelper}. */
+@RunWith(JUnit4.class)
+public final class DirectoryListingHelperTest {
+
+  private final Scratch scratch = new Scratch();
+  private final Path root = scratch.getFileSystem().getPath("/");
+
+  @Test
+  public void leafDirectoryEntries_emptyDirectory_returnsEmptyList() throws Exception {
+    assertThat(leafDirectoryEntries(root)).isEmpty();
+  }
+
+  @Test
+  public void leafDirectoryEntries_returnsFile() throws Exception {
+    scratch.file("/file");
+    assertThat(leafDirectoryEntries(root)).containsExactly(file("file"));
+  }
+
+  @Test
+  public void leafDirectoryEntries_fileInSubfolders_returnsFileOnly() throws Exception {
+    scratch.file("/dir1/dir2/file");
+    assertThat(leafDirectoryEntries(root)).containsExactly(file("dir1/dir2/file"));
+  }
+
+  @Test
+  public void leafDirectoryEntries_returnsEmptyDirectory() throws Exception {
+    scratch.dir("/dir");
+    assertThat(leafDirectoryEntries(root)).containsExactly(directory("dir"));
+  }
+
+  @Test
+  public void leafDirectoryEntries_mixedEmptyDirectoriesAndFiles_returnsAllEntries()
+      throws Exception {
+    scratch.dir("/dir/empty1");
+    scratch.dir("/dir/subdir/empty2");
+    scratch.file("/dir2/file3");
+    scratch.file("/dir2/file4");
+
+    assertThat(leafDirectoryEntries(root))
+        .containsExactly(
+            directory("dir/empty1"),
+            directory("dir/subdir/empty2"),
+            file("dir2/file3"),
+            file("dir2/file4"));
+  }
+
+  @Test
+  public void leafDirectoryEntries_returnsEntriesUnderProvidedPathOnly() throws Exception {
+    scratch.file("/dir/file1");
+    scratch.file("/dir2/file2");
+    Path dir = scratch.dir("/dir");
+
+    assertThat(leafDirectoryEntries(dir)).containsExactly(file("file1"));
+  }
+
+  @Test
+  public void leafDirectoryEntries_missingDirectory_fails() {
+    Path nonexistent = scratch.getFileSystem().getPath("/nonexistent");
+    assertThrows(FileNotFoundException.class, () -> leafDirectoryEntries(nonexistent));
+  }
+}