path: root/core/src/main/java/com/google/common/truth/StandardSubjectBuilder.java

/*
 * Copyright (c) 2011 Google, Inc.
 *
 * 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.common.truth;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Optional;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multiset;
import com.google.common.collect.Table;
import java.math.BigDecimal;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * In a fluent assertion chain, an object with which you can do any of the following:
 *
 * <ul>
 *   <li>Set an optional message with {@link #withMessage}.
 *   <li>Specify the type of {@code Subject} to create with {@link #about(Subject.Factory)}.
 *   <li>For the types of {@code Subject} built into Truth, directly specify the value under test
 *       with {@link #that(Object)}.
 * </ul>
 *
 * <p>For more information about the methods in this class, see <a
 * href="https://truth.dev/faq#full-chain">this FAQ entry</a>.
 *
 * <h3>For people extending Truth</h3>
 *
 * <p>You won't extend this type. When you write a custom subject, see <a
 * href="https://truth.dev/extension">our doc on extensions</a>.
 */
public class StandardSubjectBuilder {
  /**
   * Returns a new instance that invokes the given {@code FailureStrategy} when a check fails. Most
   * users should not need this. If you think you do, see the documentation on {@link
   * FailureStrategy}.
   */
  public static StandardSubjectBuilder forCustomFailureStrategy(FailureStrategy failureStrategy) {
    return new StandardSubjectBuilder(FailureMetadata.forFailureStrategy(failureStrategy));
  }

  private final FailureMetadata metadataDoNotReferenceDirectly;

  StandardSubjectBuilder(FailureMetadata metadata) {
    this.metadataDoNotReferenceDirectly = checkNotNull(metadata);
  }

  public final <ComparableT extends Comparable<?>> ComparableSubject<ComparableT> that(
      @Nullable ComparableT actual) {
    return new ComparableSubject<ComparableT>(metadata(), actual) {};
  }

  public final BigDecimalSubject that(@Nullable BigDecimal actual) {
    return new BigDecimalSubject(metadata(), actual);
  }

  public final Subject that(@Nullable Object actual) {
    return new Subject(metadata(), actual);
  }

  @GwtIncompatible("ClassSubject.java")
  @J2ktIncompatible
  public final ClassSubject that(@Nullable Class<?> actual) {
    return new ClassSubject(metadata(), actual);
  }

  public final ThrowableSubject that(@Nullable Throwable actual) {
    return new ThrowableSubject(metadata(), actual, "throwable");
  }

  public final LongSubject that(@Nullable Long actual) {
    return new LongSubject(metadata(), actual);
  }

  public final DoubleSubject that(@Nullable Double actual) {
    return new DoubleSubject(metadata(), actual);
  }

  public final FloatSubject that(@Nullable Float actual) {
    return new FloatSubject(metadata(), actual);
  }

  public final IntegerSubject that(@Nullable Integer actual) {
    return new IntegerSubject(metadata(), actual);
  }

  public final BooleanSubject that(@Nullable Boolean actual) {
    return new BooleanSubject(metadata(), actual);
  }

  public final StringSubject that(@Nullable String actual) {
    return new StringSubject(metadata(), actual);
  }

  public final IterableSubject that(@Nullable Iterable<?> actual) {
    return new IterableSubject(metadata(), actual);
  }

  @SuppressWarnings("AvoidObjectArrays")
  public final <T> ObjectArraySubject<T> that(@Nullable T @Nullable [] actual) {
    return new ObjectArraySubject<>(metadata(), actual, "array");
  }

  public final PrimitiveBooleanArraySubject that(boolean @Nullable [] actual) {
    return new PrimitiveBooleanArraySubject(metadata(), actual, "array");
  }

  public final PrimitiveShortArraySubject that(short @Nullable [] actual) {
    return new PrimitiveShortArraySubject(metadata(), actual, "array");
  }

  public final PrimitiveIntArraySubject that(int @Nullable [] actual) {
    return new PrimitiveIntArraySubject(metadata(), actual, "array");
  }

  public final PrimitiveLongArraySubject that(long @Nullable [] actual) {
    return new PrimitiveLongArraySubject(metadata(), actual, "array");
  }

  public final PrimitiveCharArraySubject that(char @Nullable [] actual) {
    return new PrimitiveCharArraySubject(metadata(), actual, "array");
  }

  public final PrimitiveByteArraySubject that(byte @Nullable [] actual) {
    return new PrimitiveByteArraySubject(metadata(), actual, "array");
  }

  public final PrimitiveFloatArraySubject that(float @Nullable [] actual) {
    return new PrimitiveFloatArraySubject(metadata(), actual, "array");
  }

  public final PrimitiveDoubleArraySubject that(double @Nullable [] actual) {
    return new PrimitiveDoubleArraySubject(metadata(), actual, "array");
  }

  public final GuavaOptionalSubject that(@Nullable Optional<?> actual) {
    return new GuavaOptionalSubject(metadata(), actual, "optional");
  }

  public final MapSubject that(@Nullable Map<?, ?> actual) {
    return new MapSubject(metadata(), actual);
  }

  public final MultimapSubject that(@Nullable Multimap<?, ?> actual) {
    return new MultimapSubject(metadata(), actual, "multimap");
  }

  public final MultisetSubject that(@Nullable Multiset<?> actual) {
    return new MultisetSubject(metadata(), actual);
  }

  public final TableSubject that(@Nullable Table<?, ?, ?> actual) {
    return new TableSubject(metadata(), actual);
  }

  /**
   * Returns a new instance that will output the given message before the main failure message. If
   * this method is called multiple times, the messages will appear in the order that they were
   * specified.
   */
  public final StandardSubjectBuilder withMessage(@Nullable String messageToPrepend) {
    return withMessage("%s", messageToPrepend);
  }

  /**
   * Returns a new instance that will output the given message before the main failure message. If
   * this method is called multiple times, the messages will appear in the order that they were
   * specified.
   *
   * <p><b>Note:</b> the arguments will be substituted into the format template using {@link
   * com.google.common.base.Strings#lenientFormat Strings.lenientFormat}. Note this only supports
   * the {@code %s} specifier.
   *
   * @throws IllegalArgumentException if the number of placeholders in the format string does not
   *     equal the number of given arguments
   */
  public final StandardSubjectBuilder withMessage(String format, @Nullable Object... args) {
    return new StandardSubjectBuilder(metadata().withMessage(format, args));
  }

  /**
   * Given a factory for some {@code Subject} class, returns a builder whose {@code that(actual)}
   * method creates instances of that class. Created subjects use the previously set failure
   * strategy and any previously set failure message.
   */
  public final <S extends Subject, A> SimpleSubjectBuilder<S, A> about(
      Subject.Factory<S, A> factory) {
    return new SimpleSubjectBuilder<>(metadata(), factory);
  }

  public final <CustomSubjectBuilderT extends CustomSubjectBuilder> CustomSubjectBuilderT about(
      CustomSubjectBuilder.Factory<CustomSubjectBuilderT> factory) {
    return factory.createSubjectBuilder(metadata());
  }

  /**
   * Reports a failure.
   *
   * <p>To set a message, first call {@link #withMessage} (or, more commonly, use the shortcut
   * {@link Truth#assertWithMessage}).
   */
  public final void fail() {
    metadata().fail(ImmutableList.<Fact>of());
  }

  private FailureMetadata metadata() {
    checkStatePreconditions();
    return metadataDoNotReferenceDirectly;
  }

  /**
   * Extension point invoked before every assertion. This allows {@link Expect} to check that it's
   * been set up properly as a {@code TestRule}.
   */
  void checkStatePreconditions() {}
}