converts SigningSender to typescript

Author: smartyandrewb

src/SigningSender.js

@@ -0,0 +1,32 @@
+import { Request, Response, Sender } from "./types.js";
+import SharedCredentials from "./SharedCredentials.js";
+import { UnprocessableEntityError } from "./Errors.js";
+
+interface Signer {
+    sign(request: Request): void;
+}
+
+export default class SigningSender {
+    private signer: Signer;
+    private sender: Sender;
+
+    constructor(innerSender: Sender, signer: Signer) {
+        this.signer = signer;
+        this.sender = innerSender;
+    }
+
+    send(request: Request): Promise<Response> {
+        const sendingPostWithSharedCredentials =
+            request.payload && this.signer instanceof SharedCredentials;
+        if (sendingPostWithSharedCredentials) {
+            const message =
+                "Shared credentials cannot be used in batches with a length greater than 1 or when using the US Extract API.";
+            throw new UnprocessableEntityError(message);
+        }
+
+        return new Promise((resolve, reject) => {
+            this.signer.sign(request);
+            this.sender.send(request).then(resolve).catch(reject);
+        });
+    }
+}