README.md

deepequals

Deep Java object comparison (without the need to implement equals)

• compares two objects by recursively comparing their properties - either public final fields or public no-arg methods (with any name) with non-void return type.

• It (currently) ignores equals methods except for some types: primitives and corresponding reference types, String, LocalDate and similar, enums, and Object.

• it does not require the objects to compare to be of the same runtime type and thus the user must indicate the top type used for comparison:

  Foo x = ...;
  Foo y = ...;
  assertTrue(deepEquals(Foo.class, x, y));

• Generics are fully supported by leveraging Guava's TypeToken:

  assertTrue(deepEquals(
          new TypeToken<Supplier<String>>() {},
          () -> "hello",
          new Supplier<String>() {
            @Override public String get() { return "hello"; }
          }));

• it also natively supports:

  • Optional: deep compares the contained objects recursively when appropriate.
  • Map: maps must contain the same keys. Values are deep compared.
  • Set: must contain the same elements as indicated by equals and hashCode. No deep comparison takes place.
  • List, arrays, Collection, and Iterable: deep compares the elements. Choice of strict or lenient ordering.

• supports overriding the way types/properties are compared.

• by default is expects all types involved to be data-carrying objects exclusively i.e. all methods on the objects in the tree both take no args and return something. This restriction can be relaxed, though:

  class Foo {
      public void thisMethodIsNotAProperty(/* whatever */) { ... }
      public Bar thisOneIsntEither(Baz x /*, whatever */) { ... }
      public Qux thisIsAProperty() { ... }
  }
  assertTrue(withOptions()
          .typeLenient()
          .deepEquals(Foo.class, x, y));

• other goodies ... Check out the tests for more details.