Migrating from FEST Assert 1.4 - alexruiz/fest-assert-2.x GitHub Wiki

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FEST-Assert 2.0 is not compatible with FEST-Assert 1.4, most breaking changes are minor ones thus the migration should not be difficult.

Breaking changes

Major changes

  • the package change, API is now in org.fest.assertions.api
  • onProperty feature is now extractProperty followed by from

Minor changes

  • IteratorAssert has been replaced by IterableAssert
  • satisfies() method has been replaced by is() or has() - pick the more readable
  • Delta.delta() in 1.4 becomes offset() in 2.0 (Offset class)
  • fail() method has been removed - prefer failBecauseExceptionWasNotThrown(exception class).
  • make your own assertion inheriting from AbstractAssert (more details below)
  • description() in 1.4 becomes descriptionText() in 2.0
  • excludes() in 1.4 becomes doesNotContain() in 2.0

Migration detailed steps

Migrating your own assertions

It is simple, instead of inheriting from GenericAssert you must inherit from AbstractAssert.

The parameters order in constructor is inverted, for example :

in 1.4 :

public DateTimeAssert(DateTime actual) {
    super(DateTimeAssert.class, actual);
}

in 2.0 :

public DateTimeAssert(DateTime actual) {
    super(actual, DateTimeAssert.class);
}

failure(String message) method has been replaced by fail(String message) :

throw failure(concat("expecting ", objectName, " value not to be null"));

become

Fail.fail(String.format("expecting %s value not to be null", objectName));

description() in 1.4 becomes descriptionText() in 2.0

fail() method removed

We think that when using fail in a test, one should always set a meaningful failure message, thus the removing of no arg fail() method.

Since fail() was mainly used when expecting an exception, you can replace it by failBecauseExceptionWasNotThrown(Exception class).

Executing :

failBecauseExceptionWasNotThrown(FileNotFoundException.class)

will throw an AssertionError with message "Expected FileNotFoundException to be thrown"

All fail methods are available from Assertions or Fail class.

Migrating onProperty usage toextractProperty followed by from(Class)

In Fest 1.x, you would write :

assertThat(fellowshipOfTheRing).onProperty("name").contains("Gandalf", "Frodo", "Legolas");

In Fest 2.0, it becomes :

// static import of assertThat and extractProperty
import static org.fest.assertions.api.Assertions.*;

assertThat(extractProperty("name").from(fellowshipOfTheRing)).contains("Gandalf", "Frodo", "Legolas");

// more type safe version by specifying the extracted elements type (String)
assertThat(extractProperty("name" , String.class).from(fellowshipOfTheRing)).contains("Gandalf", "Frodo", "Legolas");

We think it was more fluent and easier to read.

Easy replace with regexps

Search with regexp:

assertThat\((.*?)\).onProperty\((.*?)\)

... and replace by :

assertThat(extractProperty(\2).from(\1))

Example :

assertThat(fellowshipOfTheRing).onProperty("name").contains("Gandalf", "Frodo", "Legolas"); // Fest 1.4

... will be changed to :

assertThat(extractProperty("name").from(fellowshipOfTheRing)).contains("Gandalf", "Frodo", "Legolas"); // Fest 2.0