Add a file based package name provider

When the list of package names is too large, the test command might be too long for some system to handle. This CL adds a file based package name provider so that the test can accept files that contains long package name lists.

Test: atest :presubmit
Bug: 178392533
Change-Id: I0946e8de1c9226edb2560fd3190941b9a8edc8ed
Merged-In: I0946e8de1c9226edb2560fd3190941b9a8edc8ed
(cherry picked from commit 0aa77a2f149a74adb9961864a4cf20dfe1814dba)

4 files changed, 178 insertions, 0 deletions

diff --git a/harness/src/main/java/com/android/csuite/core/FileBasedPackageNameProvider.java b/harness/src/main/java/com/android/csuite/core/FileBasedPackageNameProvider.java
new file mode 100644
index 0000000..6f6af06
--- /dev/null
+++ b/harness/src/main/java/com/android/csuite/core/FileBasedPackageNameProvider.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * 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.android.csuite.core;
+
+import com.android.tradefed.config.Option;
+
+import com.google.common.annotations.VisibleForTesting;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/** A package name provider that accepts files that contains package names. */
+public final class FileBasedPackageNameProvider implements PackageNameProvider {
+    @VisibleForTesting static final String PACKAGES_FILE = "packages-file";
+    @VisibleForTesting static final String COMMENT_LINE_PREFIX = "#";
+
+    @Option(
+            name = PACKAGES_FILE,
+            description =
+                    "File paths that contain package names separated by newline characters."
+                        + " Comment lines are supported only if the lines start with double slash."
+                        + " Trailing comments are not supported. Empty lines are ignored.")
+    private final Set<File> mPackagesFiles = new HashSet<>();
+
+    @Override
+    public Set<String> get() throws IOException {
+        Set<String> packages = new HashSet<>();
+        for (File packagesFile : mPackagesFiles) {
+            packages.addAll(
+                    Files.readAllLines(packagesFile.toPath()).parallelStream()
+                            .map(String::trim)
+                            .filter(this::isPackageName)
+                            .collect(Collectors.toSet()));
+        }
+        return packages;
+    }
+
+    private boolean isPackageName(String text) {
+        // Check the text is not an empty string and not a comment line.
+        return !text.isEmpty() && !text.startsWith(COMMENT_LINE_PREFIX);
+    }
+}
diff --git a/harness/src/main/resources/config/csuite-base.xml b/harness/src/main/resources/config/csuite-base.xml
index 33788ab..03e418b 100644
--- a/harness/src/main/resources/config/csuite-base.xml
+++ b/harness/src/main/resources/config/csuite-base.xml
@@ -35,4 +35,5 @@
   <target_preparer class="com.android.csuite.config.ModuleGenerator" />
 
   <object type="PACKAGE_NAME_PROVIDER" class="com.android.csuite.core.CommandLinePackageNameProvider" />
+  <object type="PACKAGE_NAME_PROVIDER" class="com.android.csuite.core.FileBasedPackageNameProvider" />
 </configuration>
diff --git a/harness/src/test/java/com/android/csuite/CSuiteUnitTests.java b/harness/src/test/java/com/android/csuite/CSuiteUnitTests.java
index c97736d..8ba878d 100644
--- a/harness/src/test/java/com/android/csuite/CSuiteUnitTests.java
+++ b/harness/src/test/java/com/android/csuite/CSuiteUnitTests.java
@@ -28,6 +28,7 @@ import org.junit.runners.Suite.SuiteClasses;
     com.android.csuite.config.AppRemoteFileResolverTest.class,
     com.android.csuite.config.ModuleGeneratorTest.class,
     com.android.csuite.core.CommandLinePackageNameProviderTest.class,
+    com.android.csuite.core.FileBasedPackageNameProviderTest.class,
     com.android.csuite.testing.CorrespondencesTest.class,
     com.android.csuite.testing.MoreAssertsTest.class,
 })
diff --git a/harness/src/test/java/com/android/csuite/core/FileBasedPackageNameProviderTest.java b/harness/src/test/java/com/android/csuite/core/FileBasedPackageNameProviderTest.java
new file mode 100644
index 0000000..ee429b2
--- /dev/null
+++ b/harness/src/test/java/com/android/csuite/core/FileBasedPackageNameProviderTest.java
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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.android.csuite.core;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.android.tradefed.config.ConfigurationException;
+import com.android.tradefed.config.OptionSetter;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Set;
+
+@RunWith(JUnit4.class)
+public final class FileBasedPackageNameProviderTest {
+    private static final String TEST_PACKAGE_NAME1 = "test.package.name1";
+    private static final String TEST_PACKAGE_NAME2 = "test.package.name2";
+    private static final String PACKAGE_PLACEHOLDER = "{package}";
+    private static final Exception NO_EXCEPTION = null;
+
+    @Rule public final TemporaryFolder tempFolder = new TemporaryFolder();
+
+    @Test
+    public void get_fileNotSpecified_returnsEmptySet() throws Exception {
+        FileBasedPackageNameProvider provider = createProvider();
+
+        Set<String> packageNames = provider.get();
+
+        assertThat(packageNames).isEmpty();
+    }
+
+    @Test
+    public void get_multipleFileSpecified_returnsAllEntries() throws Exception {
+        String packageName1 = "a";
+        String packageName2 = "b";
+        String packageName3 = "c";
+        String packageName4 = "d";
+        FileBasedPackageNameProvider provider =
+                createProvider(
+                        createPackagesFile(packageName1 + "\n" + packageName2),
+                        createPackagesFile(packageName3 + "\n" + packageName4));
+
+        Set<String> packageNames = provider.get();
+
+        assertThat(packageNames)
+                .containsExactly(packageName1, packageName2, packageName3, packageName4);
+    }
+
+    @Test
+    public void get_fileContainsEmptyLines_ignoresEmptyLines() throws Exception {
+        String packageName1 = "a";
+        String packageName2 = "b";
+        FileBasedPackageNameProvider provider =
+                createProvider(createPackagesFile(packageName1 + "\n \n\n" + packageName2));
+
+        Set<String> packageNames = provider.get();
+
+        assertThat(packageNames).containsExactly(packageName1, packageName2);
+    }
+
+    @Test
+    public void get_fileContainsCommentLines_ignoresCommentLines() throws Exception {
+        String packageName1 = "a";
+        String packageName2 = "b";
+        FileBasedPackageNameProvider provider =
+                createProvider(
+                        createPackagesFile(
+                                packageName1
+                                        + "\n"
+                                        + FileBasedPackageNameProvider.COMMENT_LINE_PREFIX
+                                        + " Some comments\n"
+                                        + packageName2));
+
+        Set<String> packageNames = provider.get();
+
+        assertThat(packageNames).containsExactly(packageName1, packageName2);
+    }
+
+    private FileBasedPackageNameProvider createProvider(Path... packagesFiles)
+            throws IOException, ConfigurationException {
+        FileBasedPackageNameProvider provider = new FileBasedPackageNameProvider();
+        OptionSetter optionSetter = new OptionSetter(provider);
+        for (Path packagesFile : packagesFiles) {
+            optionSetter.setOptionValue(
+                    FileBasedPackageNameProvider.PACKAGES_FILE, packagesFile.toString());
+        }
+        return provider;
+    }
+
+    private Path createPackagesFile(String content) throws IOException {
+        Path tempFile = Files.createTempFile(tempFolder.getRoot().toPath(), "packages", ".txt");
+        Files.write(tempFile, content.getBytes());
+        return tempFile;
+    }
+}