diff --git a/src/index.test.ts b/src/index.test.ts
index 0704715..ee939ba 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -4,7 +4,7 @@ import {
 } from "https://deno.land/std@0.87.0/testing/asserts.ts";
 import { sayHello } from "./index.ts";
 import { ValidationError } from "./validation.ts";
-import { localesSize } from "./data.ts";
+import { localesSize } from "./repository/locales.ts";
 
 Deno.test("Hello test", () => {
   const actual = sayHello();
@@ -13,11 +13,19 @@ Deno.test("Hello test", () => {
 });
 
 Deno.test("Specific Hello", () => {
-  const id = 25;
-  const actual = sayHello(id);
-  const expected = "Salut le Monde!";
+  type TestCase = { in: number; want: string };
 
-  assertStrictEquals(actual, expected);
+  const testCases: TestCase[] = [
+    { in: 25, want: "Salut le Monde!" },
+    { in: 21, want: "Hello World!" },
+  ];
+
+  for (const test of testCases) {
+    const actual = sayHello(test.in);
+    const expected = test.want;
+
+    assertStrictEquals(actual, expected);
+  }
 });
 
 Deno.test("Hello fails for non strictly positive values", () => {
diff --git a/src/index.ts b/src/index.ts
index 5a6c0d3..40098be 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,15 +1,17 @@
 import { ValidationError } from "./validation.ts";
-import { localesSize } from "./data.ts";
+import { getLocaleById, localesSize } from "./repository/locales.ts";
 
 /**
  * Display the iconic Hello, World
  */
 export const sayHello = (id?: number) => {
-  if (id && idInValidRange(id)) {
+  if (!id) {
+    return;
+  }
+  if (idInValidRange(id)) {
     throw new ValidationError(`Invalid index: ${id}`);
   }
-  // const hello = getLocaleByNumber(id);
-  return (id === 5) ? "Bonjour le monde" : "Hello, World!";
+  return getLocaleById(id);
 };
 
 const idInValidRange = (id: number) => id < 1 || id >= localesSize;
diff --git a/src/data.ts b/src/repository/data.ts
similarity index 94%
rename from src/data.ts
rename to src/repository/data.ts
index b20170c..d998330 100644
--- a/src/data.ts
+++ b/src/repository/data.ts
@@ -1,4 +1,4 @@
-const locales = {
+export const locales = {
   Afrikaans: "Hallo, wêreld!",
   Albanian: "Pershëndetje Botë",
   Arabic: "أهلاً بالعالم (Ahlan bil 'Alam)",
@@ -78,9 +78,3 @@ const locales = {
   Yiddish: "העלא וועלט	(hela velt)",
   Zulu: "Sawubona Mhlaba",
 };
-
-export const localesSize = Object.keys(locales).length;
-
-export const getLocaleById = (id: number) => {
-  return Object.values(locales)[id - 1];
-};
diff --git a/src/data.test.ts b/src/repository/locales.test.ts
similarity index 86%
rename from src/data.test.ts
rename to src/repository/locales.test.ts
index 7a76487..ea5e9d2 100644
--- a/src/data.test.ts
+++ b/src/repository/locales.test.ts
@@ -1,5 +1,5 @@
 import { assertStrictEquals } from "https://deno.land/std@0.87.0/testing/asserts.ts";
-import { getLocaleById } from "./data.ts";
+import { getLocaleById } from "./locales.ts";
 
 Deno.test("Get locale by id", () => {
   const id = 25;
diff --git a/src/repository/locales.ts b/src/repository/locales.ts
new file mode 100644
index 0000000..07c827d
--- /dev/null
+++ b/src/repository/locales.ts
@@ -0,0 +1,9 @@
+import { locales } from "./data.ts";
+
+export const localesSize = Object.keys(locales).length;
+
+/**
+ * Return a given locale identified by its id
+ * @param id unique identifier
+ */
+export const getLocaleById = (id: number) => Object.values(locales)[id - 1];