Adds support for locale hash

README.md

@@ -47,6 +47,18 @@ new WireMockServer(wireMockConfig().extensions(RandomExtension.class));
 
 This will generate random first names in the `en-US` locale for every request.
 
+You can optionally add:
+* the `seed` parameter to always generate the same value for the same seed
+* the `locale` parameter to generate values in a specific locale
+
+{% raw %}
+```handle
+
+{% raw %}
+```handlebars
+{{ random 'Name.first_name' seed=1234 locale='es' }}
+```
+%}
 
 ### Technical notes
 This library brings `net.datafaker:datafaker` as transitive dependency, which may result in conflicts at building time. 

src/main/java/org/wiremock/RandomHelper.java

@@ -2,30 +2,59 @@
 
 import com.github.jknack.handlebars.Options;
 import com.github.tomakehurst.wiremock.extension.responsetemplating.helpers.HandlebarsHelper;
+import java.util.Random;
 import net.datafaker.Faker;
+import org.apache.commons.lang3.LocaleUtils;
 
 /*
  * Author: Shreya Agarwal
  */
 public class RandomHelper extends HandlebarsHelper<Object> {
 
+  private static final String SEED_HASH = "seed";
+  private static final String LOCALE_HASH = "locale";
+
+  private final Random random;
   private final Faker faker;
 
   public RandomHelper() {
-    faker = new Faker();
+    this(new Random());
+  }
+
+  RandomHelper(Random random) {
+    this.random = random;
+    this.faker = new Faker(random);
   }
 
   @Override
   public Object apply(Object context, Options options) {
+
+    // Use a seeded/localized/default Faker if `locale` or `seed` hash exist
+    final Faker myFaker = this.getFaker(options.hash(SEED_HASH), options.hash(LOCALE_HASH));
+
     try {
       // Used the `expression` method instead of `resolve` as the
       // resolve method is not able to resolve nested references in the yml files. For example, in
       // the resource file for en-US, `address.full_address` wasn't resolving because of the
       // `#{street_address}` nested reference, but `address.postcode_by_state.AL` would work fine.
       // `expression` is able to handle all cases.
-      return faker.expression("#{" + context + "}");
+      return myFaker.expression("#{" + context + "}");
     } catch (RuntimeException e) {
       return handleError("Unable to evaluate the expression " + context, e);
     }
   }
+
+  private Faker getFaker(Object seed, String locale) {
+    final Faker myFaker;
+    if (seed != null && locale != null) {
+      myFaker = new Faker(LocaleUtils.toLocale(locale), new Random(seed.hashCode()));
+    } else if (seed != null) {
+      myFaker = new Faker(new Random(seed.hashCode()));
+    } else if (locale != null) {
+      myFaker = new Faker(LocaleUtils.toLocale(locale), this.random);
+    } else {
+      myFaker = this.faker;
+    }
+    return myFaker;
+  }
 }

src/test/java/org/wiremock/RandomHelperTest.java

@@ -5,9 +5,8 @@
 
 import com.github.tomakehurst.wiremock.extension.responsetemplating.helpers.HandlebarsHelperTestBase;
 import java.io.IOException;
-import java.lang.reflect.Field;
+import java.util.HashMap;
 import java.util.Random;
-import net.datafaker.Faker;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -18,7 +17,7 @@ public class RandomHelperTest extends HandlebarsHelperTestBase {
 
   @BeforeEach
   public void init() {
-    helper = new RandomHelper();
+    helper = new RandomHelper(new Random(123456789L));
   }
 
   @Test
@@ -31,13 +30,37 @@ public void rendersAMeaningfulErrorWhenExpressionIsInvalid() throws IOException
   }
 
   @ParameterizedTest
-  @CsvSource(value = {"123456789, Name.firstName, Herb", "123456789, Name.lastName, Hauck"})
-  public void returnsRandomValue(int seed, String expression, String expected) throws Exception {
-    Field newFaker = helper.getClass().getDeclaredField("faker");
-    newFaker.setAccessible(true);
-    newFaker.set(helper, new Faker(new Random(seed)));
-
+  @CsvSource(
+      value = {
+        "Name.firstName, Herb",
+        "Name.lastName, Hauck",
+      })
+  public void returnsRandomValue(String expression, String expected) throws Exception {
     String actual = renderHelperValue(helper, expression);
     assertThat(actual, is(expected));
   }
+
+  @ParameterizedTest
+  @CsvSource(
+      value = {
+        ", , Herb",
+        ", es, José María",
+        ", fr_QC, Clément",
+        "1, , Donny",
+        "hello, , Nickie",
+        "test, de, Franz"
+      })
+  public void rendersSeededLocalizedRandomValue(Object seed, Object locale, String expected) {
+    final var map = new HashMap<String, Object>();
+    if (seed != null) {
+      map.put("seed", seed);
+    }
+    if (locale != null) {
+      map.put("locale", locale);
+    }
+
+    final var actual = helper.apply("Name.firstName", createOptions(map));
+
+    assertThat(actual, is(expected));
+  }
 }