### Tested { #tested }

* 100% <dfn title="The amount of code that is automatically tested">test coverage</dfn>.
* 100% <dfn title="Python type annotations, with this your editor and external tools can give you better support">type annotated</dfn> code base.

# Eine Datenbank testen { #testing-a-database }

Sie können sich über Datenbanken, SQL und SQLModel in der [SQLModel-Dokumentation](https://sqlmodel.tiangolo.com/) informieren. 🤓

Es gibt ein kurzes [Tutorial zur Verwendung von SQLModel mit FastAPI](https://sqlmodel.tiangolo.com/tutorial/fastapi/). ✨

    assertEquals(expectedHash, in.hash());
  }

  public void testChecksForNull() throws Exception {
    NullPointerTester tester = new NullPointerTester();

    tester.testAllPublicInstanceMethods(new HashingInputStream(sha512(), buffer));
    tester.testAllPublicStaticMethods(HashingInputStream.class);
    tester.testAllPublicConstructors(HashingInputStream.class);
  }

    assertEquals(expectedHash, in.hash());
  }

  public void testChecksForNull() throws Exception {
    NullPointerTester tester = new NullPointerTester();

    tester.testAllPublicInstanceMethods(new HashingInputStream(sha512(), buffer));
    tester.testAllPublicStaticMethods(HashingInputStream.class);
    tester.testAllPublicConstructors(HashingInputStream.class);
  }

    for (Method method : methods) {
      if (method.isAnnotationPresent(TestSubtype.class)) {
        method.setAccessible(true);
        SubtypeTester tester = (SubtypeTester) clone();
        tester.method = method;
        method.invoke(tester, new Object[] {null});
      }
    }
  }

  private Type getOnlyParameterType() {
    assertThat(method.getGenericParameterTypes()).hasLength(1);

I tested several ideas in the most popular Python editors: PyCharm, VS Code, Jedi based editors.

By the last [Python Developer Survey](https://www.jetbrains.com/research/python-developers-survey-2018/#development-tools), that covers about 80% of the users.

import java.util.Collection;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates collections, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public interface TestCollectionGenerator<E extends @Nullable Object>

available system. This will take a very long time.
+
Fortunately, the various systems under test have their own Gradle tasks under
`qa/os`. To find the systems tested, do a listing of the `qa/os` directory.
To find out what packaging combinations can be tested on a system, run
the `tasks` task. For example:
+
----------------------------------
./gradlew :qa:os:ubuntu-1804:tasks
----------------------------------
+

        ? Predicates.<T>isNull()
        : new IsEqualToPredicate(target).withNarrowedType();
  }

  /**
   * Returns a predicate that evaluates to {@code true} if the object being tested is an instance of
   * the given class. If the object being tested is {@code null} this predicate evaluates to {@code
   * false}.
   *
   * <p>If you want to filter an {@code Iterable} to narrow its type, consider using {@link

 */

package com.google.common.collect.testing.features;

import com.google.common.annotations.GwtCompatible;
import java.util.Set;

/**
 * Base class for enumerating the features of an interface to be tested.
 *
 * @param <T> The interface whose features are to be enumerated.
 * @author George van den Driessche
 */
@GwtCompatible
public interface Feature<T> {