feat: add contract testing with OpenAPI spec for Todos API

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: kevinccbsg

contracts/todos-3.0.json

@@ -0,0 +1,111 @@
+{
+  "openapi": "3.0.0",
+  "info": {
+    "title": "Todos API",
+    "version": "1.0.0"
+  },
+  "paths": {
+    "/todos": {
+      "get": {
+        "operationId": "getTodos",
+        "responses": {
+          "200": {
+            "description": "List of todos",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/components/schemas/Todo"
+                  }
+                }
+              }
+            }
+          }
+        }
+      },
+      "post": {
+        "operationId": "createTodo",
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/NewTodo"
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Created todo",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/Todo"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/todos/{id}": {
+      "delete": {
+        "operationId": "deleteTodo",
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "string"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Todo deleted"
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "Todo": {
+        "type": "object",
+        "required": ["id", "title", "description", "date"],
+        "properties": {
+          "id": {
+            "type": "string"
+          },
+          "title": {
+            "type": "string"
+          },
+          "description": {
+            "type": "string"
+          },
+          "date": {
+            "type": "string"
+          }
+        }
+      },
+      "NewTodo": {
+        "type": "object",
+        "required": ["title", "description", "date"],
+        "properties": {
+          "title": {
+            "type": "string"
+          },
+          "description": {
+            "type": "string"
+          },
+          "date": {
+            "type": "string"
+          }
+        }
+      }
+    }
+  }
+}

twd.config.json

@@ -0,0 +1,12 @@
+{
+  "url": "http://localhost:5173",
+  "contractReportPath": ".twd/contract-report.md",
+  "contracts": [
+    {
+      "source": "./contracts/todos-3.0.json",
+      "baseUrl": "/api",
+      "mode": "error",
+      "strict": true
+    }
+  ]
+}