feat: TDD migration of owners/pets/visits from Angular to React 18

.gitignore

@@ -7,6 +7,7 @@
 
 # dependencies
 /node_modules
+react-frontend/node_modules
 
 # IDEs and editors
 /.idea

docs/API_CONTRACT.md

@@ -0,0 +1,366 @@
+# API Contract — Owners, Pets, Visits
+
+Base URL: `http://localhost:9966/petclinic/api/`
+
+---
+
+## Owners
+
+### List / Search Owners
+
+```
+GET /owners
+GET /owners?lastName={lastName}
+```
+
+**Response:** `200 OK`
+```json
+[
+  {
+    "id": 1,
+    "firstName": "George",
+    "lastName": "Franklin",
+    "address": "110 W. Liberty St.",
+    "city": "Madison",
+    "telephone": "6085551023",
+    "pets": [
+      {
+        "id": 1,
+        "name": "Leo",
+        "birthDate": "2010-09-07",
+        "type": { "id": 1, "name": "cat" },
+        "ownerId": 1,
+        "owner": null,
+        "visits": []
+      }
+    ]
+  }
+]
+```
+
+### Get Owner by ID
+
+```
+GET /owners/:ownerId
+```
+
+**Response:** `200 OK`
+```json
+{
+  "id": 1,
+  "firstName": "George",
+  "lastName": "Franklin",
+  "address": "110 W. Liberty St.",
+  "city": "Madison",
+  "telephone": "6085551023",
+  "pets": []
+}
+```
+
+**Error:** `404 Not Found`
+
+### Create Owner
+
+```
+POST /owners
+Content-Type: application/json
+```
+
+**Request Body:**
+```json
+{
+  "firstName": "George",
+  "lastName": "Franklin",
+  "address": "110 W. Liberty St.",
+  "city": "Madison",
+  "telephone": "6085551023"
+}
+```
+
+**Response:** `201 Created`
+```json
+{
+  "id": 1,
+  "firstName": "George",
+  "lastName": "Franklin",
+  "address": "110 W. Liberty St.",
+  "city": "Madison",
+  "telephone": "6085551023",
+  "pets": []
+}
+```
+
+### Update Owner
+
+```
+PUT /owners/:ownerId
+Content-Type: application/json
+```
+
+**Request Body:**
+```json
+{
+  "id": 1,
+  "firstName": "George",
+  "lastName": "Franklin",
+  "address": "110 W. Liberty St.",
+  "city": "Madison",
+  "telephone": "6085551023"
+}
+```
+
+**Response:** `204 No Content`
+
+### Delete Owner
+
+```
+DELETE /owners/:ownerId
+```
+
+**Response:** `204 No Content`
+
+---
+
+## Pets
+
+### List All Pets
+
+```
+GET /pets
+```
+
+**Response:** `200 OK`
+```json
+[
+  {
+    "id": 1,
+    "name": "Leo",
+    "birthDate": "2010-09-07",
+    "type": { "id": 1, "name": "cat" },
+    "ownerId": 1,
+    "owner": { "id": 1, "firstName": "George", "lastName": "Franklin", "address": "...", "city": "...", "telephone": "...", "pets": [] },
+    "visits": []
+  }
+]
+```
+
+### Get Pet by ID
+
+```
+GET /pets/:petId
+```
+
+**Response:** `200 OK`
+```json
+{
+  "id": 1,
+  "name": "Leo",
+  "birthDate": "2010-09-07",
+  "type": { "id": 1, "name": "cat" },
+  "ownerId": 1,
+  "owner": { "id": 1, "firstName": "George", "lastName": "Franklin", "address": "...", "city": "...", "telephone": "...", "pets": [] },
+  "visits": []
+}
+```
+
+**Error:** `404 Not Found`
+
+### Add Pet to Owner
+
+```
+POST /owners/:ownerId/pets
+Content-Type: application/json
+```
+
+**Request Body:**
+```json
+{
+  "name": "Leo",
+  "birthDate": "2010-09-07",
+  "type": { "id": 1, "name": "cat" }
+}
+```
+
+**Response:** `201 Created`
+```json
+{
+  "id": 1,
+  "name": "Leo",
+  "birthDate": "2010-09-07",
+  "type": { "id": 1, "name": "cat" },
+  "ownerId": 1,
+  "owner": null,
+  "visits": []
+}
+```
+
+### Update Pet
+
+```
+PUT /pets/:petId
+Content-Type: application/json
+```
+
+**Request Body:**
+```json
+{
+  "id": 1,
+  "name": "Leo",
+  "birthDate": "2010-09-07",
+  "type": { "id": 1, "name": "cat" },
+  "ownerId": 1
+}
+```
+
+**Response:** `204 No Content`
+
+### Delete Pet
+
+```
+DELETE /pets/:petId
+```
+
+**Response:** `204 No Content`
+
+---
+
+## Visits
+
+### List All Visits
+
+```
+GET /visits
+```
+
+**Response:** `200 OK`
+```json
+[
+  {
+    "id": 1,
+    "date": "2023-01-01",
+    "description": "Annual checkup",
+    "pet": { "id": 1, "name": "Leo", "birthDate": "2010-09-07", "type": { "id": 1, "name": "cat" }, "ownerId": 1, "owner": null, "visits": [] },
+    "petId": 1
+  }
+]
+```
+
+### Get Visit by ID
+
+```
+GET /visits/:visitId
+```
+
+**Response:** `200 OK`
+```json
+{
+  "id": 1,
+  "date": "2023-01-01",
+  "description": "Annual checkup",
+  "pet": { "id": 1, "name": "Leo", "birthDate": "...", "type": {...}, "ownerId": 1, "owner": null, "visits": [] },
+  "petId": 1
+}
+```
+
+**Error:** `404 Not Found`
+
+### Add Visit to Pet
+
+```
+POST /owners/:ownerId/pets/:petId/visits
+Content-Type: application/json
+```
+
+**Request Body:**
+```json
+{
+  "date": "2023-01-01",
+  "description": "Annual checkup"
+}
+```
+
+**Response:** `201 Created`
+```json
+{
+  "id": 1,
+  "date": "2023-01-01",
+  "description": "Annual checkup",
+  "pet": null,
+  "petId": 1
+}
+```
+
+### Update Visit
+
+```
+PUT /visits/:visitId
+Content-Type: application/json
+```
+
+**Request Body:**
+```json
+{
+  "id": 1,
+  "date": "2023-01-01",
+  "description": "Updated checkup notes"
+}
+```
+
+**Response:** `204 No Content`
+
+### Delete Visit
+
+```
+DELETE /visits/:visitId
+```
+
+**Response:** `204 No Content`
+
+---
+
+## Common Types
+
+### Owner
+| Field       | Type     | Description            |
+|-------------|----------|------------------------|
+| id          | number   | Unique identifier      |
+| firstName   | string   | Owner's first name     |
+| lastName    | string   | Owner's last name      |
+| address     | string   | Street address         |
+| city        | string   | City                   |
+| telephone   | string   | Phone number           |
+| pets        | Pet[]    | Associated pets        |
+
+### Pet
+| Field      | Type     | Description             |
+|------------|----------|-------------------------|
+| id         | number   | Unique identifier       |
+| name       | string   | Pet name                |
+| birthDate  | string   | ISO date (YYYY-MM-DD)   |
+| type       | PetType  | Species/breed category  |
+| ownerId    | number   | FK to owner             |
+| owner      | Owner    | Owner object (nullable) |
+| visits     | Visit[]  | Associated visits       |
+
+### PetType
+| Field | Type   | Description        |
+|-------|--------|--------------------|
+| id    | number | Unique identifier  |
+| name  | string | Type name (e.g., "cat") |
+
+### Visit
+| Field       | Type   | Description             |
+|-------------|--------|-------------------------|
+| id          | number | Unique identifier       |
+| date        | string | ISO date (YYYY-MM-DD)   |
+| description | string | Visit notes             |
+| pet         | Pet    | Associated pet (nullable)|
+| petId       | number | FK to pet (optional)    |
+
+---
+
+## Error Handling
+
+- `404 Not Found` — resource does not exist
+- `400 Bad Request` — validation failure (missing required fields)
+- Network errors — connection refused / timeout

react-frontend/index.html

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>PetClinic React</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>