blob: 5408e728a65542ca4b7cd366f52c362ef3820f00 [file] [log] [blame]
// Copyright 2019 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.supplier;
import static com.google.common.truth.Truth.assertThat;
import com.google.common.testing.GcFinalization;
import java.lang.ref.WeakReference;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
/** Tests for {@link MemoizingInterruptibleSupplier}. */
@RunWith(JUnit4.class)
public final class MemoizingInterruptibleSupplierTest {
private int callCount = 0;
private String returnVal = "";
private CallCounter callCounter = new CallCounter();
private final class CallCounter {
public String call() {
++callCount;
return returnVal;
}
}
@Test
public void getReturnsCorrectResult() throws Exception {
MemoizingInterruptibleSupplier<String> supplier =
MemoizingInterruptibleSupplier.of(callCounter::call);
returnVal = "abc";
String result = supplier.get();
assertThat(result).isEqualTo("abc");
}
@Test
public void subsequentCallToGetReturnsCorrectResult() throws Exception {
MemoizingInterruptibleSupplier<String> supplier =
MemoizingInterruptibleSupplier.of(callCounter::call);
returnVal = "abc";
supplier.get();
String result = supplier.get();
assertThat(result).isEqualTo("abc");
}
@Test
public void onlyCallsDelegateOnce() throws Exception {
MemoizingInterruptibleSupplier<String> supplier =
MemoizingInterruptibleSupplier.of(callCounter::call);
supplier.get();
supplier.get();
assertThat(callCount).isEqualTo(1);
}
@Test
public void freesReferenceToDelegeteAfterGet() throws Exception {
MemoizingInterruptibleSupplier<String> supplier =
MemoizingInterruptibleSupplier.of(callCounter::call);
WeakReference<Object> ref = new WeakReference<>(callCounter);
callCounter = null;
supplier.get();
GcFinalization.awaitClear(ref);
}
@Test
public void notInitializedBeforeCallingGet() {
MemoizingInterruptibleSupplier<String> supplier =
MemoizingInterruptibleSupplier.of(callCounter::call);
boolean initialized = supplier.isInitialized();
assertThat(initialized).isFalse();
}
@Test
public void isInitializedAfterCallingGet() throws Exception {
MemoizingInterruptibleSupplier<String> supplier =
MemoizingInterruptibleSupplier.of(callCounter::call);
supplier.get();
boolean initialized = supplier.isInitialized();
assertThat(initialized).isTrue();
}
@Test
public void isStillInitializedAfterSubsequentCallToGet() throws Exception {
MemoizingInterruptibleSupplier<String> supplier =
MemoizingInterruptibleSupplier.of(callCounter::call);
supplier.get();
supplier.get();
boolean initialized = supplier.isInitialized();
assertThat(initialized).isTrue();
}
@Test
public void of_returnsSameInstanceIfAlreadyMemoizing() {
InterruptibleSupplier<String> supplier = MemoizingInterruptibleSupplier.of(callCounter::call);
assertThat(MemoizingInterruptibleSupplier.of(supplier)).isSameInstanceAs(supplier);
}
}