| // Copyright 2017 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.syntax; |
| |
| import static com.google.common.truth.Truth.assertThat; |
| import static org.junit.Assert.assertThrows; |
| |
| import com.google.devtools.build.lib.syntax.Mutability.Freezable; |
| import org.junit.Test; |
| import org.junit.runner.RunWith; |
| import org.junit.runners.JUnit4; |
| |
| /** Tests for {@link Mutability}. */ |
| @RunWith(JUnit4.class) |
| public final class MutabilityTest { |
| |
| /** A trivial Freezable that can do nothing but freeze. */ |
| private static class DummyFreezable implements Mutability.Freezable { |
| private final Mutability mutability; |
| |
| public DummyFreezable(Mutability mutability) { |
| this.mutability = mutability; |
| } |
| |
| @Override |
| public Mutability mutability() { |
| return mutability; |
| } |
| } |
| |
| private static void assertCheckMutableFailsBecauseFrozen(DummyFreezable x) { |
| EvalException ex = assertThrows(EvalException.class, () -> Starlark.checkMutable(x)); |
| assertThat(ex).hasMessageThat().contains("trying to mutate a frozen DummyFreezable value"); |
| } |
| |
| @Test |
| public void freeze() throws Exception { |
| Mutability mutability = Mutability.create("test"); |
| DummyFreezable dummy = new DummyFreezable(mutability); |
| |
| Starlark.checkMutable(dummy); |
| mutability.freeze(); |
| assertCheckMutableFailsBecauseFrozen(dummy); |
| } |
| |
| @Test |
| public void tryWithResources() throws Exception { |
| DummyFreezable dummy; |
| try (Mutability mutability = Mutability.create("test")) { |
| dummy = new DummyFreezable(mutability); |
| Starlark.checkMutable(dummy); |
| } |
| assertCheckMutableFailsBecauseFrozen(dummy); |
| } |
| |
| @Test |
| public void initiallyMutable() throws Exception { |
| Mutability mutability = Mutability.create("test"); |
| DummyFreezable dummy = new DummyFreezable(mutability); |
| |
| Starlark.checkMutable(dummy); |
| } |
| |
| @Test |
| public void temporarilyImmutableDuringIteration() throws Exception { |
| Mutability mutability = Mutability.create("test"); |
| DummyFreezable x = new DummyFreezable(mutability); |
| x.updateIteratorCount(+1); |
| EvalException ex = assertThrows(EvalException.class, () -> Starlark.checkMutable(x)); |
| assertThat(ex) |
| .hasMessageThat() |
| .contains("DummyFreezable value is temporarily immutable due to active for-loop iteration"); |
| |
| x.updateIteratorCount(+1); |
| x.updateIteratorCount(-1); // net +1 => still immutable |
| ex = assertThrows(EvalException.class, () -> Starlark.checkMutable(x)); |
| assertThat(ex) |
| .hasMessageThat() |
| .contains("DummyFreezable value is temporarily immutable due to active for-loop iteration"); |
| |
| x.updateIteratorCount(-1); // net 0 => mutable |
| Starlark.checkMutable(x); // ok |
| |
| assertThrows(IllegalStateException.class, () -> x.updateIteratorCount(-1)); // underflow |
| } |
| |
| @Test |
| public void addIteratorAndThenFreeze() throws Exception { |
| Mutability mutability = Mutability.create("test"); |
| DummyFreezable dummy = new DummyFreezable(mutability); |
| dummy.updateIteratorCount(+1); |
| mutability.freeze(); |
| // Should fail with frozen error, not temporarily immutable error. |
| assertCheckMutableFailsBecauseFrozen(dummy); |
| } |
| |
| @Test |
| public void checkUnsafeShallowFreezePrecondition_FailsWhenAlreadyFrozen() throws Exception { |
| Mutability mutability = Mutability.create("test").freeze(); |
| assertThrows( |
| IllegalArgumentException.class, |
| () -> Freezable.checkUnsafeShallowFreezePrecondition(new DummyFreezable(mutability))); |
| } |
| |
| @Test |
| public void checkUnsafeShallowFreezePrecondition_FailsWhenDisallowed() throws Exception { |
| Mutability mutability = Mutability.create("test"); |
| assertThrows( |
| IllegalArgumentException.class, |
| () -> Freezable.checkUnsafeShallowFreezePrecondition(new DummyFreezable(mutability))); |
| } |
| |
| @Test |
| public void checkUnsafeShallowFreezePrecondition_SucceedsWhenAllowed() throws Exception { |
| Mutability mutability = Mutability.createAllowingShallowFreeze("test"); |
| Freezable.checkUnsafeShallowFreezePrecondition(new DummyFreezable(mutability)); |
| } |
| } |