diff --git a/src/test/java/com/google/devtools/build/lib/BUILD b/src/test/java/com/google/devtools/build/lib/BUILD
index 4fba77d494764b..0c1d90cd8ac7b2 100644
--- a/src/test/java/com/google/devtools/build/lib/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/BUILD
@@ -1261,6 +1261,7 @@ java_test(
         "//src/main/java/com/google/devtools/build/lib:bazel-modules",
         "//src/main/java/com/google/devtools/build/lib:bazel-rules",
         "//src/main/java/com/google/devtools/build/lib:build-base",
+        "//src/main/java/com/google/devtools/build/lib:build-request-options",
         "//src/main/java/com/google/devtools/build/lib:loading-phase-threads-option",
         "//src/main/java/com/google/devtools/build/lib:packages",
         "//src/main/java/com/google/devtools/build/lib:runtime",
diff --git a/src/test/java/com/google/devtools/build/lib/runtime/commands/TargetPatternFileSupportTest.java b/src/test/java/com/google/devtools/build/lib/runtime/commands/TargetPatternFileSupportTest.java
new file mode 100644
index 00000000000000..e97afffdddad71
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/runtime/commands/TargetPatternFileSupportTest.java
@@ -0,0 +1,103 @@
+// Copyright 2020 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.runtime.commands;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;
+import static org.mockito.Mockito.when;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.analysis.ServerDirectories;
+import com.google.devtools.build.lib.buildtool.BuildRequestOptions;
+import com.google.devtools.build.lib.runtime.BlazeRuntime;
+import com.google.devtools.build.lib.runtime.BlazeServerStartupOptions;
+import com.google.devtools.build.lib.runtime.CommandEnvironment;
+import com.google.devtools.build.lib.runtime.commands.TargetPatternFileSupport.TargetPatternFileSupportException;
+import com.google.devtools.build.lib.testutil.Scratch;
+import com.google.devtools.build.lib.testutil.TestConstants;
+import com.google.devtools.common.options.OptionsParser;
+import com.google.devtools.common.options.OptionsParsingException;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.Mockito;
+
+/** Tests {@link TargetPatternFileSupport}. */
+@RunWith(JUnit4.class)
+public class TargetPatternFileSupportTest {
+
+  private CommandEnvironment env;
+  private Scratch scratch;
+  private OptionsParser options;
+
+  @Before
+  public void setUp() throws Exception {
+    options =
+        OptionsParser.builder().optionsClasses(BuildRequestOptions.class).build();
+    scratch = new Scratch();
+    BlazeRuntime runtime =
+        new BlazeRuntime.Builder()
+            .setFileSystem(scratch.getFileSystem())
+            .setProductName(TestConstants.PRODUCT_NAME)
+            .setServerDirectories(
+                new ServerDirectories(
+                    scratch.resolve("/install"),
+                    scratch.resolve("/base"),
+                    scratch.resolve("/userRoot")))
+            .setStartupOptionsProvider(
+                OptionsParser.builder().optionsClasses(BlazeServerStartupOptions.class).build())
+            .build();
+    env = Mockito.mock(CommandEnvironment.class);
+    when(env.getWorkingDirectory()).thenReturn(scratch.resolve("wd"));
+    when(env.getRuntime()).thenReturn(runtime);
+  }
+
+  @Test
+  public void testTargetPatternFile() throws Exception {
+    scratch.file("/wd/patterns.txt", "//some/...\n//patterns");
+    options.parse("--target_pattern_file=patterns.txt");
+
+    assertThat(TargetPatternFileSupport.handleTargetPatternFile(env, options))
+        .isEqualTo(ImmutableList.of("//some/...", "//patterns"));
+  }
+
+  @Test
+  public void testNoTargetPatternFile() throws TargetPatternFileSupportException {
+    ImmutableList<String> patterns = ImmutableList.of("//some/...", "//patterns");
+    options.setResidue(patterns);
+
+    assertThat(TargetPatternFileSupport.handleTargetPatternFile(env, options))
+        .isEqualTo(patterns);
+  }
+
+  @Test
+  public void testSpecifyPatternAndFileThrows() throws OptionsParsingException {
+    options.parse("--target_pattern_file=patterns.txt");
+    options.setResidue(ImmutableList.of("//some:pattern"));
+
+    assertThrows(
+        TargetPatternFileSupport.TargetPatternFileSupportException.class,
+        () -> TargetPatternFileSupport.handleTargetPatternFile(env, options));
+  }
+
+  @Test
+  public void testSpecifyNonExistingFileThrows() throws OptionsParsingException {
+    options.parse("--target_pattern_file=patterns.txt");
+
+    assertThrows(
+        TargetPatternFileSupport.TargetPatternFileSupportException.class,
+        () -> TargetPatternFileSupport.handleTargetPatternFile(env, options));
+  }
+}