fix tests

Author: nhsd-david-wass

scripts/utilities/letter-test-data/src/__test__/helpers/create-letter-helpers.test.ts

@@ -4,9 +4,9 @@ import {
   createLetter,
   createLetterDto,
 } from "../../helpers/create-letter-helpers";
-import { uploadFile } from "../../helpers/s3-helpers";
+import uploadFile from "../../helpers/s3-helpers";
 
-jest.mock("../../helpers/s3_helpers");
+jest.mock("../../helpers/s3-helpers");
 
 describe("Create letter helpers", () => {
   beforeEach(() => {

scripts/utilities/letter-test-data/src/__test__/helpers/s3-helpers.test.ts

@@ -0,0 +1,87 @@
+/**
+ * Unit tests for s3-helpers.ts
+ *
+ * Mocks:
+ * - @aws-sdk/client-s3: S3Client (with send) and PutObjectCommand
+ * - node:fs.readFileSync to avoid touching the filesystem
+ */
+
+import * as s3Module from "@aws-sdk/client-s3";
+import uploadFile from "../../helpers/s3-helpers";
+
+jest.mock("@aws-sdk/client-s3", () => {
+  const sendMock = jest.fn();
+  class PutObjectCommand {
+    input: any;
+
+    constructor(input: any) {
+      this.input = input;
+    }
+  }
+  const S3Client = jest.fn().mockImplementation(() => ({ send: sendMock }));
+  return {
+    S3Client,
+    PutObjectCommand,
+    __sendMock: sendMock,
+    __esModule: true,
+  };
+});
+
+jest.mock("node:fs", () => ({
+  readFileSync: jest.fn().mockReturnValue(Buffer.from("fake-pdf-bytes")),
+}));
+
+describe("uploadFile", () => {
+  const bucket = "my-bucket";
+  const supplierId = "supplier-1";
+  const sourceFilename = "some.pdf";
+  const targetFilename = "target.pdf";
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it("calls S3Client.send with a PutObjectCommand containing correct params", async () => {
+    const sendMock = (s3Module as any).__sendMock as jest.Mock;
+    sendMock.mockResolvedValue({ ETag: '"etag-value"' });
+
+    await expect(
+      uploadFile(bucket, supplierId, sourceFilename, targetFilename),
+    ).resolves.toBeDefined();
+
+    // S3Client is a mocked constructor — grab the instance that was created
+    const S3ClientMock = (s3Module as any).S3Client as jest.Mock;
+    expect(S3ClientMock).toHaveBeenCalled();
+
+    const instance = S3ClientMock.mock.results[0].value;
+    expect(instance.send).toHaveBeenCalledTimes(1);
+
+    const calledWith = instance.send.mock.calls[0][0];
+    // The mocked PutObjectCommand stores input as `input` property
+    expect(calledWith).toHaveProperty("input");
+    expect(calledWith.input).toEqual({
+      Bucket: bucket,
+      Key: `${supplierId}/${targetFilename}`,
+      Body: Buffer.from("fake-pdf-bytes"),
+      ContentType: "application/pdf",
+    });
+  });
+
+  it("logs and rethrows when S3Client.send rejects", async () => {
+    const sendMock = (s3Module as any).__sendMock as jest.Mock;
+    const err = new Error("upload-failed");
+    sendMock.mockRejectedValueOnce(err);
+
+    const consoleSpy = jest
+      .spyOn(console, "error")
+      .mockImplementation(() => {});
+
+    await expect(
+      uploadFile(bucket, supplierId, sourceFilename, targetFilename),
+    ).rejects.toThrow("upload-failed");
+
+    expect(consoleSpy).toHaveBeenCalledWith("Error uploading file:", err);
+
+    consoleSpy.mockRestore();
+  });
+});

scripts/utilities/letter-test-data/src/helpers/create-letter-helpers.ts

@@ -3,7 +3,7 @@ import {
   LetterRepository,
   LetterStatusType,
 } from "@internal/datastore";
-import { uploadFile } from "./s3-helpers";
+import uploadFile from "./s3-helpers";
 
 export async function createLetter(params: {
   letterId: string;