Move constraint value lookup to a new utility function.

Change-Id: I13645199a21991b1458264f9d9ac2db2736066b2
PiperOrigin-RevId: 204963740
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/ConstraintValueLookupUtilTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/ConstraintValueLookupUtilTest.java
new file mode 100644
index 0000000..fe9f0ff
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/ConstraintValueLookupUtilTest.java
@@ -0,0 +1,204 @@
+// Copyright 2018 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.skyframe;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.devtools.build.skyframe.EvaluationResultSubjectFactory.assertThatEvaluationResult;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.analysis.BlazeDirectories;
+import com.google.devtools.build.lib.analysis.platform.ConstraintValueInfo;
+import com.google.devtools.build.lib.analysis.util.AnalysisMock;
+import com.google.devtools.build.lib.rules.platform.ToolchainTestCase;
+import com.google.devtools.build.lib.skyframe.ConstraintValueLookupUtil.InvalidConstraintValueException;
+import com.google.devtools.build.lib.skyframe.util.SkyframeExecutorTestUtils;
+import com.google.devtools.build.skyframe.EvaluationResult;
+import com.google.devtools.build.skyframe.SkyFunction;
+import com.google.devtools.build.skyframe.SkyFunctionException;
+import com.google.devtools.build.skyframe.SkyFunctionName;
+import com.google.devtools.build.skyframe.SkyKey;
+import com.google.devtools.build.skyframe.SkyValue;
+import java.util.List;
+import javax.annotation.Nullable;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link ConstraintValueLookupUtil}. */
+@RunWith(JUnit4.class)
+public class ConstraintValueLookupUtilTest extends ToolchainTestCase {
+
+  /**
+   * An {@link AnalysisMock} that injects {@link GetConstraintValueInfoFunction} into the Skyframe
+   * executor.
+   */
+  private static final class AnalysisMockWithGetPlatformInfoFunction extends AnalysisMock.Delegate {
+    AnalysisMockWithGetPlatformInfoFunction() {
+      super(AnalysisMock.get());
+    }
+
+    @Override
+    public ImmutableMap<SkyFunctionName, SkyFunction> getSkyFunctions(
+        BlazeDirectories directories) {
+      return ImmutableMap.<SkyFunctionName, SkyFunction>builder()
+          .putAll(super.getSkyFunctions(directories))
+          .put(GET_CONSTRAINT_VALUE_INFO_FUNCTION, new GetConstraintValueInfoFunction())
+          .build();
+    }
+  }
+
+  @Override
+  protected AnalysisMock getAnalysisMock() {
+    return new AnalysisMockWithGetPlatformInfoFunction();
+  }
+
+  @Test
+  public void testConstraintValueLookup() throws Exception {
+    ConfiguredTargetKey linuxKey =
+        ConfiguredTargetKey.of(makeLabel("//constraints:linux"), targetConfigKey, false);
+    ConfiguredTargetKey macKey =
+        ConfiguredTargetKey.of(makeLabel("//constraints:mac"), targetConfigKey, false);
+    GetConstraintValueInfoKey key =
+        GetConstraintValueInfoKey.create(ImmutableList.of(linuxKey, macKey));
+
+    EvaluationResult<GetConstraintValueInfoValue> result = getConstraintValueInfo(key);
+
+    assertThatEvaluationResult(result).hasNoError();
+    assertThatEvaluationResult(result).hasEntryThat(key).isNotNull();
+
+    List<ConstraintValueInfo> constraintValues = result.get(key).constraintValues();
+    assertThat(constraintValues).contains(linuxConstraint);
+    assertThat(constraintValues).contains(macConstraint);
+    assertThat(constraintValues).hasSize(2);
+  }
+
+  @Test
+  public void testConstraintValueLookup_targetNotConstraintValue() throws Exception {
+    scratch.file("invalid/BUILD", "filegroup(name = 'not_a_constraint')");
+
+    ConfiguredTargetKey targetKey =
+        ConfiguredTargetKey.of(makeLabel("//invalid:not_a_constraint"), targetConfigKey, false);
+    GetConstraintValueInfoKey key = GetConstraintValueInfoKey.create(ImmutableList.of(targetKey));
+
+    EvaluationResult<GetConstraintValueInfoValue> result = getConstraintValueInfo(key);
+
+    assertThatEvaluationResult(result).hasError();
+    assertThatEvaluationResult(result)
+        .hasErrorEntryForKeyThat(key)
+        .hasExceptionThat()
+        .isInstanceOf(InvalidConstraintValueException.class);
+    assertThatEvaluationResult(result)
+        .hasErrorEntryForKeyThat(key)
+        .hasExceptionThat()
+        .hasMessageThat()
+        .contains("//invalid:not_a_constraint");
+  }
+
+  @Test
+  public void testConstraintValueLookup_targetDoesNotExist() throws Exception {
+    ConfiguredTargetKey targetKey =
+        ConfiguredTargetKey.of(makeLabel("//fake:missing"), targetConfigKey, false);
+    GetConstraintValueInfoKey key = GetConstraintValueInfoKey.create(ImmutableList.of(targetKey));
+
+    EvaluationResult<GetConstraintValueInfoValue> result = getConstraintValueInfo(key);
+
+    assertThatEvaluationResult(result).hasError();
+    assertThatEvaluationResult(result)
+        .hasErrorEntryForKeyThat(key)
+        .hasExceptionThat()
+        .isInstanceOf(InvalidConstraintValueException.class);
+    assertThatEvaluationResult(result)
+        .hasErrorEntryForKeyThat(key)
+        .hasExceptionThat()
+        .hasMessageThat()
+        .contains("no such package 'fake': BUILD file not found on package path");
+  }
+
+  // Calls ConstraintValueLookupUtil.getConstraintValueInfo.
+  private static final SkyFunctionName GET_CONSTRAINT_VALUE_INFO_FUNCTION =
+      SkyFunctionName.createHermetic("GET_CONSTRAINT_VALUE_INFO_FUNCTION");
+
+  @AutoValue
+  abstract static class GetConstraintValueInfoKey implements SkyKey {
+    @Override
+    public SkyFunctionName functionName() {
+      return GET_CONSTRAINT_VALUE_INFO_FUNCTION;
+    }
+
+    abstract Iterable<ConfiguredTargetKey> constraintValueKeys();
+
+    public static GetConstraintValueInfoKey create(
+        Iterable<ConfiguredTargetKey> constraintValueKeys) {
+      return new AutoValue_ConstraintValueLookupUtilTest_GetConstraintValueInfoKey(
+          constraintValueKeys);
+    }
+  }
+
+  EvaluationResult<GetConstraintValueInfoValue> getConstraintValueInfo(
+      GetConstraintValueInfoKey key) throws InterruptedException {
+    try {
+      // Must re-enable analysis for Skyframe functions that create configured targets.
+      skyframeExecutor.getSkyframeBuildView().enableAnalysis(true);
+      return SkyframeExecutorTestUtils.evaluate(
+          skyframeExecutor, key, /*keepGoing=*/ false, reporter);
+    } finally {
+      skyframeExecutor.getSkyframeBuildView().enableAnalysis(false);
+    }
+  }
+
+  @AutoValue
+  abstract static class GetConstraintValueInfoValue implements SkyValue {
+    abstract List<ConstraintValueInfo> constraintValues();
+
+    static GetConstraintValueInfoValue create(List<ConstraintValueInfo> constraintValues) {
+      return new AutoValue_ConstraintValueLookupUtilTest_GetConstraintValueInfoValue(
+          constraintValues);
+    }
+  }
+
+  private static final class GetConstraintValueInfoFunction implements SkyFunction {
+
+    @Nullable
+    @Override
+    public SkyValue compute(SkyKey skyKey, Environment env)
+        throws SkyFunctionException, InterruptedException {
+      GetConstraintValueInfoKey key = (GetConstraintValueInfoKey) skyKey;
+      try {
+        List<ConstraintValueInfo> constraintValues =
+            ConstraintValueLookupUtil.getConstraintValueInfo(key.constraintValueKeys(), env);
+        if (env.valuesMissing()) {
+          return null;
+        }
+        return GetConstraintValueInfoValue.create(constraintValues);
+      } catch (InvalidConstraintValueException e) {
+        throw new GetConstraintValueInfoFunctionException(e);
+      }
+    }
+
+    @Nullable
+    @Override
+    public String extractTag(SkyKey skyKey) {
+      return null;
+    }
+  }
+
+  private static class GetConstraintValueInfoFunctionException extends SkyFunctionException {
+    public GetConstraintValueInfoFunctionException(InvalidConstraintValueException e) {
+      super(e, Transience.PERSISTENT);
+    }
+  }
+}