src/test/java/com/google/devtools/build/lib/packages/StarlarkProviderTest.java

// 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.packages;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verifyNoInteractions;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.testing.EqualsTester;
import com.google.devtools.build.lib.cmdline.Label;
import net.starlark.java.eval.Dict;
import net.starlark.java.eval.EvalException;
import net.starlark.java.eval.Mutability;
import net.starlark.java.eval.Starlark;
import net.starlark.java.eval.StarlarkCallable;
import net.starlark.java.eval.StarlarkInt;
import net.starlark.java.eval.StarlarkSemantics;
import net.starlark.java.eval.StarlarkThread;
import net.starlark.java.eval.Tuple;
import net.starlark.java.syntax.Location;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests for {@link StarlarkProvider}. */
@RunWith(JUnit4.class)
public final class StarlarkProviderTest {

  @Test
  public void unexportedProvider_accessors() {
    StarlarkProvider provider = StarlarkProvider.builder(Location.BUILTIN).build();
    assertThat(provider.isExported()).isFalse();
    assertThat(provider.getName()).isEqualTo("<no name>");
    assertThat(provider.getPrintableName()).isEqualTo("<no name>");
    assertThat(provider.createRawConstructor().getName()).isEqualTo("<raw constructor>");
    assertThat(provider.getErrorMessageForUnknownField("foo"))
        .isEqualTo("'struct' value has no field or method 'foo'");
    assertThat(provider.isImmutable()).isFalse();
    assertThat(Starlark.repr(provider)).isEqualTo("<provider>");
    assertThrows(IllegalStateException.class, provider::getKey);
  }

  @Test
  public void exportedProvider_accessors() throws Exception {
    StarlarkProvider.Key key =
        new StarlarkProvider.Key(Label.parseCanonical("//foo:bar.bzl"), "prov");
    StarlarkProvider provider = StarlarkProvider.builder(Location.BUILTIN).setExported(key).build();
    assertThat(provider.isExported()).isTrue();
    assertThat(provider.getName()).isEqualTo("prov");
    assertThat(provider.getPrintableName()).isEqualTo("prov");
    assertThat(provider.createRawConstructor().getName()).isEqualTo("<raw constructor for prov>");
    assertThat(provider.getErrorMessageForUnknownField("foo"))
        .isEqualTo("'prov' value has no field or method 'foo'");
    assertThat(provider.isImmutable()).isTrue();
    assertThat(Starlark.repr(provider)).isEqualTo("<provider>");
    assertThat(provider.getKey()).isEqualTo(key);
  }

  @Test
  public void basicInstantiation() throws Exception {
    StarlarkProvider provider = StarlarkProvider.builder(Location.BUILTIN).build();
    StarlarkInfo infoFromNormalConstructor = instantiateWithA1B2C3(provider);
    assertHasExactlyValuesA1B2C3(infoFromNormalConstructor);
    assertThat(infoFromNormalConstructor.getProvider()).isEqualTo(provider);

    StarlarkInfo infoFromRawConstructor = instantiateWithA1B2C3(provider.createRawConstructor());
    assertHasExactlyValuesA1B2C3(infoFromRawConstructor);
    assertThat(infoFromRawConstructor.getProvider()).isEqualTo(provider);

    assertThat(infoFromNormalConstructor).isEqualTo(infoFromRawConstructor);
  }

  @Test
  public void instantiationWithInit() throws Exception {
    StarlarkProvider provider = StarlarkProvider.builder(Location.BUILTIN).setInit(initBC).build();
    StarlarkInfo infoFromNormalConstructor = instantiateWithA1(provider);
    assertHasExactlyValuesA1B2C3(infoFromNormalConstructor);
    assertThat(infoFromNormalConstructor.getProvider()).isEqualTo(provider);
  }

  @Test
  public void instantiationWithInitSignatureMismatch_fails() throws Exception {
    StarlarkProvider provider = StarlarkProvider.builder(Location.BUILTIN).setInit(initBC).build();
    EvalException e = assertThrows(EvalException.class, () -> instantiateWithA1B2C3(provider));
    assertThat(e).hasMessageThat().contains("expected a single `a` argument");
  }

  @Test
  public void instantiationWithInitReturnTypeMismatch_fails() throws Exception {
    StarlarkCallable initWithInvalidReturnType =
        new StarlarkCallable() {
          @Override
          public Object call(StarlarkThread thread, Tuple args, Dict<String, Object> kwargs) {
            return "invalid";
          }

          @Override
          public String getName() {
            return "initWithInvalidReturnType";
          }

          @Override
          public Location getLocation() {
            return Location.BUILTIN;
          }
        };

    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN).setInit(initWithInvalidReturnType).build();
    EvalException e = assertThrows(EvalException.class, () -> instantiateWithA1B2C3(provider));
    assertThat(e)
        .hasMessageThat()
        .contains("got string for 'return value of provider init()', want dict");
  }

  @Test
  public void instantiationWithFailingInit_fails() throws Exception {
    StarlarkCallable failingInit =
        new StarlarkCallable() {
          @Override
          public Object call(StarlarkThread thread, Tuple args, Dict<String, Object> kwargs)
              throws EvalException {
            throw Starlark.errorf("failingInit fails");
          }

          @Override
          public String getName() {
            return "failingInit";
          }

          @Override
          public Location getLocation() {
            return Location.BUILTIN;
          }
        };

    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN).setInit(failingInit).build();
    EvalException e = assertThrows(EvalException.class, () -> instantiateWithA1B2C3(provider));
    assertThat(e).hasMessageThat().contains("failingInit fails");
  }

  @Test
  public void rawConstructorBypassesInit() throws Exception {
    StarlarkCallable init = mock(StarlarkCallable.class, "init");
    StarlarkProvider provider = StarlarkProvider.builder(Location.BUILTIN).setInit(init).build();
    StarlarkInfo infoFromRawConstructor = instantiateWithA1B2C3(provider.createRawConstructor());
    assertHasExactlyValuesA1B2C3(infoFromRawConstructor);
    assertThat(infoFromRawConstructor.getProvider()).isEqualTo(provider);
    verifyNoInteractions(init);
  }

  @Test
  public void basicInstantiationWithSchemaWithSomeFieldsUnset() throws Exception {
    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN)
            .setSchema(ImmutableList.of("a", "b", "c"))
            .build();
    StarlarkInfo infoFromNormalConstructor = instantiateWithA1(provider);
    assertHasExactlyValuesA1(infoFromNormalConstructor);
    StarlarkInfo infoFromRawConstructor = instantiateWithA1(provider.createRawConstructor());
    assertHasExactlyValuesA1(infoFromRawConstructor);
  }

  @Test
  public void basicInstantiationWithSchemaWithAllFieldsSet() throws Exception {
    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN)
            .setSchema(ImmutableList.of("a", "b", "c"))
            .build();
    StarlarkInfo infoFromNormalConstructor = instantiateWithA1B2C3(provider);
    assertHasExactlyValuesA1B2C3(infoFromNormalConstructor);
    StarlarkInfo infoFromRawConstructor = instantiateWithA1B2C3(provider.createRawConstructor());
    assertHasExactlyValuesA1B2C3(infoFromRawConstructor);
  }

  @Test
  public void schemaDisallowsUnexpectedFields() throws Exception {
    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN).setSchema(ImmutableList.of("a", "b")).build();
    EvalException e = assertThrows(EvalException.class, () -> instantiateWithA1B2C3(provider));
    assertThat(e)
        .hasMessageThat()
        .contains("got unexpected field 'c' in call to instantiate provider");
  }

  @Test
  public void schemaEnforcedOnRawConstructor() throws Exception {
    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN).setSchema(ImmutableList.of("a", "b")).build();
    EvalException e =
        assertThrows(
            EvalException.class, () -> instantiateWithA1B2C3(provider.createRawConstructor()));
    assertThat(e)
        .hasMessageThat()
        .contains("got unexpected field 'c' in call to instantiate provider");
  }

  @Test
  public void schemaEnforcedOnInit() throws Exception {
    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN)
            .setSchema(ImmutableList.of("a", "b"))
            .setInit(initBC)
            .build();
    EvalException e = assertThrows(EvalException.class, () -> instantiateWithA1(provider));
    assertThat(e)
        .hasMessageThat()
        .contains("got unexpected field 'c' in call to instantiate provider");
  }

  @Test
  public void schemalessProvider_getFields() throws Exception {
    StarlarkProvider provider = StarlarkProvider.builder(Location.BUILTIN).build();
    assertThat(provider.getFields()).isNull();
  }

  @Test
  public void schemafulProvider_getFields() throws Exception {
    StarlarkProvider provider =
        StarlarkProvider.builder(Location.BUILTIN)
            .setSchema(ImmutableList.of("a", "b", "c"))
            .build();
    assertThat(provider.getFields()).containsExactly("a", "b", "c").inOrder();
  }

  @Test
  public void providerEquals() throws Exception {
    // All permutations of differing label and differing name.
    StarlarkProvider.Key keyFooA =
        new StarlarkProvider.Key(Label.parseCanonical("//foo.bzl"), "provA");
    StarlarkProvider.Key keyFooB =
        new StarlarkProvider.Key(Label.parseCanonical("//foo.bzl"), "provB");
    StarlarkProvider.Key keyBarA =
        new StarlarkProvider.Key(Label.parseCanonical("//bar.bzl"), "provA");
    StarlarkProvider.Key keyBarB =
        new StarlarkProvider.Key(Label.parseCanonical("//bar.bzl"), "provB");

    // 1 for each key, plus a duplicate for one of the keys, plus 2 that have no key.
    StarlarkProvider provFooA1 =
        StarlarkProvider.builder(Location.BUILTIN).setExported(keyFooA).build();
    StarlarkProvider provFooA2 =
        StarlarkProvider.builder(Location.BUILTIN).setExported(keyFooA).build();
    StarlarkProvider provFooB =
        StarlarkProvider.builder(Location.BUILTIN).setExported(keyFooB).build();
    StarlarkProvider provBarA =
        StarlarkProvider.builder(Location.BUILTIN).setExported(keyBarA).build();
    StarlarkProvider provBarB =
        StarlarkProvider.builder(Location.BUILTIN).setExported(keyBarB).build();
    StarlarkProvider provUnexported1 = StarlarkProvider.builder(Location.BUILTIN).build();
    StarlarkProvider provUnexported2 = StarlarkProvider.builder(Location.BUILTIN).build();

    // For exported providers, different keys -> unequal, same key -> equal. For unexported
    // providers it comes down to object identity.
    new EqualsTester()
        .addEqualityGroup(provFooA1, provFooA2)
        .addEqualityGroup(provFooB)
        .addEqualityGroup(provBarA, provBarA) // reflexive equality (exported)
        .addEqualityGroup(provBarB)
        .addEqualityGroup(provUnexported1, provUnexported1) // reflexive equality (unexported)
        .addEqualityGroup(provUnexported2)
        .testEquals();
  }

  /** Custom init equivalent to `def initBC(a): return {a:a, b:a*2, c:a*3}` */
  private static final StarlarkCallable initBC =
      new StarlarkCallable() {
        @Override
        public Object call(StarlarkThread thread, Tuple args, Dict<String, Object> kwargs)
            throws EvalException {
          if (!args.isEmpty()) {
            throw Starlark.errorf("unexpected positional arguments");
          }
          if (kwargs.size() != 1 || !kwargs.containsKey("a")) {
            throw Starlark.errorf("expected a single `a` argument");
          }
          StarlarkInt a = (StarlarkInt) kwargs.get("a");
          return Dict.builder()
              .put("a", a)
              .put("b", StarlarkInt.of(a.toIntUnchecked() * 2))
              .put("c", StarlarkInt.of(a.toIntUnchecked() * 3))
              .build(Mutability.IMMUTABLE);
        }

        @Override
        public String getName() {
          return "initBC";
        }

        @Override
        public Location getLocation() {
          return Location.BUILTIN;
        }
      };

  /** Instantiates a {@link StarlarkInfo} with fields a=1 (and nothing else). */
  private static StarlarkInfo instantiateWithA1(StarlarkCallable provider) throws Exception {
    try (Mutability mu = Mutability.create()) {
      StarlarkThread thread = new StarlarkThread(mu, StarlarkSemantics.DEFAULT);
      Object result =
          Starlark.call(
              thread,
              provider,
              /*args=*/ ImmutableList.of(),
              /*kwargs=*/ ImmutableMap.of("a", StarlarkInt.of(1)));
      assertThat(result).isInstanceOf(StarlarkInfo.class);
      return (StarlarkInfo) result;
    }
  }

  /** Instantiates a {@link StarlarkInfo} with fields a=1, b=2, c=3 (and nothing else). */
  private static StarlarkInfo instantiateWithA1B2C3(StarlarkCallable provider) throws Exception {
    try (Mutability mu = Mutability.create()) {
      StarlarkThread thread = new StarlarkThread(mu, StarlarkSemantics.DEFAULT);
      Object result =
          Starlark.call(
              thread,
              provider,
              /*args=*/ ImmutableList.of(),
              /*kwargs=*/ ImmutableMap.of(
                  "a", StarlarkInt.of(1), "b", StarlarkInt.of(2), "c", StarlarkInt.of(3)));
      assertThat(result).isInstanceOf(StarlarkInfo.class);
      return (StarlarkInfo) result;
    }
  }

  /** Asserts that a {@link StarlarkInfo} has field a=1 (and nothing else). */
  private static void assertHasExactlyValuesA1(StarlarkInfo info) throws Exception {
    assertThat(info.getFieldNames()).containsExactly("a");
    assertThat(info.getValue("a")).isEqualTo(StarlarkInt.of(1));
  }

  /** Asserts that a {@link StarlarkInfo} has fields a=1, b=2, c=3 (and nothing else). */
  private static void assertHasExactlyValuesA1B2C3(StarlarkInfo info) throws Exception {
    assertThat(info.getFieldNames()).containsExactly("a", "b", "c");
    assertThat(info.getValue("a")).isEqualTo(StarlarkInt.of(1));
    assertThat(info.getValue("b")).isEqualTo(StarlarkInt.of(2));
    assertThat(info.getValue("c")).isEqualTo(StarlarkInt.of(3));
  }
}