handle base64-encoded request bodies (#10)

Sources/Vercel/InvokeEvent.swift

@@ -13,6 +13,7 @@ public struct InvokeEvent: Codable, Sendable {
         public let headers: HTTPHeaders
         public let path: String
         public let body: String?
+        public let encoding: String?
     }
 
     public let body: String

Sources/Vercel/Request.swift

@@ -10,16 +10,30 @@ public struct Request: Sendable {
     public let headers: HTTPHeaders
     public let path: String
     public let searchParams: [String: String]
-    public let body: String?
+    public let rawBody: Data?
 
     /// Private instance var to prevent decodable from failing
     public internal(set) var pathParams: Parameters = .init()
 
+    public var body: String? {
+        if let rawBody = rawBody {
+            return String(bytes: rawBody, encoding: .utf8)
+        }
+
+        return nil
+    }
+
     internal init(_ payload: InvokeEvent.Payload) {
         self.method = payload.method
         self.headers = payload.headers
         self.path = payload.path
-        self.body = payload.body
+
+        if let encoding = payload.encoding, let body = payload.body, encoding == "base64" {
+            rawBody = Data(base64Encoded: body)
+        } else {
+            rawBody = payload.body?.data(using: .utf8)
+        }
+
         self.searchParams = URLComponents(string: payload.path)?
             .queryItems?
             .reduce(into: [:]) { $0[$1.name] = $1.value } ?? [:]

Tests/VercelTests/RequestTests.swift

@@ -46,4 +46,35 @@ final class RequestTests: XCTestCase {
         XCTAssertEqual(req.method, .GET)
         XCTAssertEqual(req.searchParams["token"], "12345")
     }
+
+    func testPlainBody() throws {
+        let json = """
+        {
+          "method": "PUT",
+          "path": "/",
+          "headers": {},
+          "body": "hello"
+        }
+        """
+        let payload = try JSONDecoder().decode(InvokeEvent.Payload.self, from: json.data(using: .utf8)!)
+        let req = Request(payload)
+        XCTAssertEqual(req.body, "hello")
+    }
+
+    func testBase64Body() throws {
+        let json = """
+        {
+          "method": "PUT",
+          "path": "/",
+          "headers": {},
+          "body": "/////w==",
+          "encoding": "base64"
+        }
+        """
+        let payload = try JSONDecoder().decode(InvokeEvent.Payload.self, from: json.data(using: .utf8)!)
+        let req = Request(payload)
+        let expectData: [UInt8] = [0xff, 0xff, 0xff, 0xff]
+        XCTAssertEqual(req.rawBody, Data(expectData))
+        XCTAssertNil(req.body)
+    }
 }