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Overhead-less DbC library
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A package to provide entry-point classes for the `Fluent` style.

The goal of the "fluent" style of the `pcond` library is to make it possible:

- To be able to rely on IDE's help for recalling what you can do now.
- To write tests in a readable and consistent manner.
- To show a readable report failure when a test fails.
- Not to need to a custom support class for your own class.

That is, if you have a following example code:

[source, java]
.Example Test Code
----
public class FluentStyleExample {
  @Test
  public void givenKnownLastName_whenFindMembersByFullName_thenLastNastIsNotNullAndContainedInFullName() {
    // Find a user entry from a member database
    MemberDatabase database = new MemberDatabase();
    String lastName = database.lookUp("0001")
        .orElseThrow(NoSuchElementException::new)
        .lastName();
    List fullName = database.findMembersByLastName(lastName).get(0).toFullName();
    // Check if
    // - The last name of the entry is not null and not an empty string.
    // - The last name is "DOE".
    assertWhen(
        value(lastName)
            .then()
            .verifyWith(allOf(
                isNotNull(),
                not(isEmptyString()))),
        value(fullName).asListOfClass(String.class)
            .then()
            .contains("DOE"));
  }
}
----

May result in the following output:

[%nowrap]
.Output Example
----
 "Doe"               ->WHEN:treatAsIs      ->"Doe"                | "Doe"               ->WHEN:treatAsIs      ->"Doe"
                       THEN:&&             ->true                 |                       THEN:&&             ->true
                           isNotNull       ->true                 |                            isNotNull      ->true
                           !               ->true                 |                            !              ->true
                             isEmpty       ->false                |                              isEmpty      ->false
 ["John","Doe","PhD"]->WHEN:treatAsList    ->["John","Doe","PhD"] | ["John","Doe","PhD"]->WHEN:treatAsList    ->["John","Doe","PhD"]
X                      THEN:contains["DOE"]->true                 |                       THEN:contains["DOE"]->false
----

== Special Types of `pcond`

In the `pcond` library divides an evaluation of an assertion into two stages.
"Transform" and "check".
Not like other assertion libraries, it has separated group of classes for each of them.
"Transformers"

In order to reduce the necessity of creating custom classes, it takes an approach, where

They are `String`, `Number`(`Integer`), `Boolean`, `List`, `Stream`, and (general) `Object`.
For each of them, special `Transformer` s and `Checker` s come with the `pcond` library to provide type specific methods, such as `containsString` for `String`.