[Java] Allow parameter types access to test context

[mpkorstanje]

Summary

By annotating methods parameter and data table types can be defined as part of the Glue. This enables them to access the test context and makes them eligible for dependency injection. Additionally the type registry is now created for each feature. This means the language of the feature will be used to convert numbers.

Details

Parameter and DataTable Type

Introduces the @ParameterType and @DataTableType annotations. This allows parameter and datatable types to be mapped to objects which can only be created by services inside the test context.

For example in this scenario

Given the awesome catalog
When a user places the awestruck eels in his basket
Then you will be shocked at what happened next

We are now able to look up the "awestruck eels" in the "awesome" catalog.

private final Catalog catalog;

@ParameterType(".*")
public Product product(String name) {
  return catalog.findProductByName(name);
}

Default Transformer

It is now also possible to register default transformers using annotations. Default transformers allow you to specific a transformer that will be used when there is no transform defined. This can
be combined with an object mapper like Jackson to quickly transform well known string representations to Java objects.

• @DefaultParameterTransformer
• @DefaultDataTableEntryTransformer
• @DefaultDataTableCellTransformer

package com.example.app;

import com.fasterxml.jackson.databind.ObjectMapper;
import io.cucumber.java.DefaultDataTableCellTransformer;
import io.cucumber.java.DefaultDataTableEntryTransformer;
import io.cucumber.java.DefaultParameterTransformer;

import java.lang.reflect.Type;

public class DataTableSteps {

   private final ObjectMapper objectMapper = new ObjectMapper();

   @DefaultParameterTransformer
   @DefaultDataTableEntryTransformer
   @DefaultDataTableCellTransformer
   public Object defaultTransformer(Object fromValue, Type toValueType) {
       return objectMapper.convertValue(fromValue, objectMapper.constructType(toValueType));
   }
}

Localization

Some languages uses comma's rather then points to separate decimals. Previously to parse these properly you'd have to use TypeRegistryConfigurer.locale to set this globally. When not explicitly provided Cucumber will now take the language from the feature file. This makes the following work without additional configuration:

# language: fr
Fonctionnalité: Concombres fractionnaires

  Scénario: dans la ventre
    Étant donné j'ai 5,5 concombres fractionnaires

@Étantdonné("j'ai {bigdecimal} concombres fractionnaires")
public void jAiConcombresFractionnaires(BigDecimal arg0) {
    assertThat(arg0, is(new BigDecimal("5.5")));
}

Motivation & Context

Fixes #851.
Fixes #1458.

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklist:

• I've added tests for my code.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.