# old/mod.ts
export function greet(name: string) {}

# new/mod.ts
export function greet(name: string, greeting?: string) {}

# output.json
{
  "modifiedModules": {
    "file:///mod.ts": {
      "modified": [
        {
          "name": "greet",
          "declarations": {
            "modified": [
              {
                "kind": "function",
                "defChanges": {
                  "type": "function",
                  "paramsChange": {
                    "added": [
                      {
                        "kind": "identifier",
                        "name": "greeting",
                        "optional": true,
                        "tsType": {
                          "repr": "string",
                          "kind": "keyword",
                          "value": "string"
                        }
                      }
                    ]
                  }
                }
              }
            ]
          }
        }
      ]
    }
  }
}
