CCM-13475: Send print events #179

simonlabarere · 2026-01-13T13:22:31Z

Description

Create new Print Sender component that triggers a Letter Prepared Event to be eventually passed to the Supplier API from a Letter Analysed Event.

Contains changes from #174 to pull packages from GitHub.

Note: When merging main, @nhsdigital/nhs-notify-event-schemas-supplier-api was updated to 1.0.10, which introduces a breaking change requiring billingRef in the events. As this change is not yet supported, the dependency has been temporarily pinned to 1.0.6.

Test evidence

Print Sender logs

Event Bus logs

Input Letter Analysed event + Output Letter Prepared event

Event is published to the cross domain event bus

Type of changes

Refactoring (non-breaking change)
New feature (non-breaking change which adds functionality)
Breaking change (fix or feature that would change existing functionality)
Bug fix (non-breaking change which fixes an issue)

Checklist

I am familiar with the contributing guidelines
I have followed the code style of the project
I have added tests to cover my changes
I have updated the documentation accordingly
This PR is a result of pair or mob programming
If I have used the 'skip-trivy-package' label I have done so responsibly and in the knowledge that this is being fixed as part of a separate ticket/PR.

Sensitive Information Declaration

To ensure the utmost confidentiality and protect your and others privacy, we kindly ask you to NOT including PII (Personal Identifiable Information) / PID (Personal Identifiable Data) or any other sensitive data in this PR (Pull Request) and the codebase changes. We will remove any PR that do contain any sensitive information. We really appreciate your cooperation in this matter.

I confirm that neither PII/PID nor sensitive data are included in this PR and the codebase changes.

nhsd-angel-pastor · 2026-01-15T09:59:56Z

infrastructure/terraform/components/dl/cloudwatch_event_rule_letter_prepared.tf

+  event_pattern = jsonencode({
+    "detail" : {
+      "type" : [
+        "uk.nhs.notify.letter-rendering.letter-request.prepared.v1"


Quick question, in the confluence page https://nhsd-confluence.digital.nhs.uk/spaces/RIS/pages/1196005217/REFCOM-2025-079+%F0%9F%9F%A2+EVENT+letter-rendering.letter-request.PREPARED.v1 at the top of the page it appears as:

uk.nhs.notify.letter-rendering.letter-request.prepared.v1

where as the other 4 references are with PREPARED i.e.

uk.nhs.notify.letter-rendering.letter-request.PREPARED.v1

I presume is the way you got it, but just double checking.

Nice catch! The event validator supplied by the supplier API event package requires lower case otherwise it fails validation. That's why I went with prepared I'm not 100% sure that's correct.

nhsd-angel-pastor · 2026-01-15T10:52:51Z

infrastructure/terraform/components/dl/module_sqs_print_sender.tf

+    ]
+
+    resources = [
+      "arn:aws:sqs:${var.region}:${var.aws_account_id}:${var.project}-${var.environment}-${local.component}-print-sender-queue"


tiny one, is it worth using ${local.csi} instead of ${var.project}-${var.environment}-${local.component}? from the file terraform/components/dl/locals_tfscaffold.tf:

csi = replace(
format(
"%s-%s-%s",
var.project,
var.environment,
local.component,
),
"_",
"",
)

lambdas/print-sender-lambda/src/app/print-sender.ts

nhsd-angel-pastor · 2026-01-29T10:57:13Z

infrastructure/terraform/components/dl/modules_eventpub.tf

+
+  kms_key_arn           = module.kms.key_arn
+  log_retention_in_days = var.log_retention_in_days
+  log_level             = "INFO"


We have the variable "log_level" to define the log level for the lambdas, do we want another variable for the evenpub? or do we want to reuse it as we do in "log_retention_in_days"?

I presume for Prod more likely we use INFO level, but probably is a question for infra whether we need a new variable or we're ok to leave it as INFO.

I think we can use the "log_level" variable. I'll make the change, thanks!

nhsd-angel-pastor · 2026-01-29T11:41:32Z

lambdas/print-sender-lambda/src/app/print-sender.ts

+          status: 'PREPARED',
+          url: item.data.letterUri,
+          clientId: item.data.senderId,
+          letterVariantId: 'notify-digital-letter-standard',


From https://nhsd-jira.digital.nhs.uk/browse/CCM-13475, do we need the campaignId?

….0.6

nhsd-angel-pastor · 2026-01-30T08:55:32Z

tests/playwright/digital-letters-component-tests/print-sender.component.spec.ts

+import expectToPassEventually from 'helpers/expectations';
+import { v4 as uuidv4 } from 'uuid';
+
+test.describe('Digital Letters - Print Sender', () => {


do we want to add a test to cover the scenario of messages going to the DLQ?

I've noticed we have in terraform modules_eventpub.tf, is that the way that we expose our event to the digital letters API? If so, just wondering if the test should have an extra assert by subscribing to an SNS topic and getting the message

nhsd-angel-pastor · 2026-01-30T08:56:56Z

infrastructure/terraform/components/dl/modules_eventpub.tf

+module "eventpub" {
+  source = "https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.30/terraform-eventpub.zip"
+
+  name = "eventpub"


is this how we expose the events to the digital letters API? just wondering if the name should be a bit more descriptive.

gareth-allan · 2026-01-30T15:54:57Z

docs/package-lock.json

Does this file need changing, if we've not touched anything else in the docs directory?

gareth-allan · 2026-01-30T15:59:06Z

lambdas/print-sender-lambda/package.json

@@ -0,0 +1,25 @@
+{
+  "dependencies": {
+    "@aws-sdk/lib-dynamodb": "^3.908.0",


This dependency isn't used (we're not using DynamoDB in this lambda!).

gareth-allan · 2026-01-30T16:57:58Z

lambdas/print-sender-lambda/src/__tests__/app/print-sender.test.ts

+    it('should return failed when event validation fails', async () => {
+      mockEventPublisher.sendEvents.mockRejectedValue(
+        new Error('Validation error'),
+      );
+
+      const result = await printSender.send(mockPDFAnalysed);
+
+      expect(result).toBe('failed');
+      expect(mockLogger.error).toHaveBeenCalled();
+    });


This test is doing the same thing as should return failed when event publisher throws error. The only difference is the message of the Error.

Could you pass an invalid event into send to verify that it handles validation failures instead?

gareth-allan · 2026-01-30T17:08:06Z

lambdas/print-sender-lambda/src/__tests__/app/print-sender.test.ts

+    it('should handle different sender IDs and message references', async () => {
+      const customInput: PDFAnalysed = {
+        ...mockPDFAnalysed,
+        data: {
+          ...mockPDFAnalysed.data,
+          senderId: 'custom-sender-999',
+          messageReference: 'custom-ref-abc',
+        },
+      };
+
+      await printSender.send(customInput);
+
+      const [[events]] = mockEventPublisher.sendEvents.mock.calls;
+      const event = events[0] as LetterRequestPreparedEvent;
+
+      expect(event.data.domainId).toBe('custom-sender-999_custom-ref-abc');
+      expect(event.data.clientId).toBe('custom-sender-999');
+      expect(event.data.requestItemPlanId).toBe('custom-ref-abc');
+      expect(event.subject).toBe(
+        'client/custom-sender-999/letter-request/custom-ref-abc',
+      );
+    });


Does this verify anything that should successfully send a letter prepared event doesn't?

gareth-allan · 2026-01-30T17:15:39Z

lambdas/print-sender-lambda/src/apis/sqs-trigger-lambda.ts

+      },
+    );
+
+    const results = await Promise.allSettled(promises);


All we do with the results array is check the length of it for the log statement, and given we always return a result for every record I think we could just use sqsEvent.Records.length instead, and remove the whole mechanism of returning a result from each promise.

gareth-allan · 2026-01-30T17:25:10Z

lambdas/print-sender-lambda/src/__tests__/apis/sqs-trigger-lambda.test.ts

+  it('should process valid SQS messages successfully', async () => {
+    const validEvent = createValidEvent();
+    const sqsEvent: SQSEvent = {
+      Records: [
+        createSQSRecord(JSON.stringify({ detail: validEvent }), 'message-1'),
+      ],
+    };
+
+    mockPrintSender.send.mockResolvedValue('sent');
+
+    const result = await handler(sqsEvent);
+
+    expect(result.batchItemFailures).toEqual([]);
+    expect(mockPrintSender.send).toHaveBeenCalledWith(validEvent);
+    expect(mockLogger.info).toHaveBeenCalledWith(
+      expect.objectContaining({
+        description: 'Processed SQS Event.',
+        retrieved: 1,
+        sent: 1,
+        failed: 0,
+      }),
+    );
+  });


I think it might be nicer to have this happy path test send multiple records, as it's verifying the counts of items logged that should handle multiple messages in batch doesn't.

gareth-allan · 2026-01-30T17:26:08Z

lambdas/print-sender-lambda/src/__tests__/apis/sqs-trigger-lambda.test.ts

+  it('should handle partial batch failures', async () => {
+    const event1 = createValidEvent({ id: 'id-1' });
+    const event2 = createValidEvent({ id: 'id-2' });
+    const sqsEvent: SQSEvent = {
+      Records: [
+        createSQSRecord(JSON.stringify({ detail: event1 }), 'message-1'),
+        createSQSRecord(JSON.stringify({ detail: event2 }), 'message-2'),
+      ],
+    };
+
+    mockPrintSender.send
+      .mockResolvedValueOnce('sent')
+      .mockResolvedValueOnce('failed');
+
+    const result = await handler(sqsEvent);
+
+    expect(result.batchItemFailures).toEqual([{ itemIdentifier: 'message-2' }]);
+    expect(mockLogger.info).toHaveBeenCalledWith(
+      expect.objectContaining({
+        retrieved: 2,
+        sent: 1,
+        failed: 1,
+      }),
+    );
+  });


I think this one would be good if it included more than one failing record, to verify we're building the batchItemFailures list correctly.

gareth-allan · 2026-01-30T17:30:10Z

infrastructure/terraform/components/dl/module_sqs_print_sender.tf

+
+    resources = [
+      "arn:aws:sqs:${var.region}:${var.aws_account_id}:${local.csi}-print-sender-queue"
+    ]


We should have a condition here in the same way as we do for module_sqd_print_analyser.tf:

Suggested change

]

]

condition {

test = "ArnEquals"

variable = "aws:SourceArn"

values = [aws_cloudwatch_event_rule.pdf_analysed.arn]

}

simonlabarere requested review from a team as code owners January 13, 2026 13:22

simonlabarere and others added 3 commits January 13, 2026 13:31

CCM-13475: Send print events

b96894d

CCM-12614: add github package manager authentication

b47da0a

CCM-12614: add github package manager authentication

d9a4b1a

simonlabarere force-pushed the feature/CCM-13475_send_print_events branch from 61703dc to d9a4b1a Compare January 13, 2026 13:33

simonlabarere requested a review from a team as a code owner January 13, 2026 13:33

simonlabarere force-pushed the feature/CCM-13475_send_print_events branch 2 times, most recently from 16dabad to d9a4b1a Compare January 13, 2026 13:57

simonlabarere added 7 commits January 13, 2026 14:06

CCM-13475: Github token fix attempt

883f871

CCM-13475: Send print events

f2e18ae

CCM-13475: Send print events

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CCM-13475: Send print events

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Merge branch 'main' into feature/CCM-13475_send_print_events

a1ce01c

CCM-13475: Send print events

d3a28ec

CCM-14347: Send Print config

cbe7ee4

nhsd-angel-pastor reviewed Jan 15, 2026

View reviewed changes

lambdas/print-sender-lambda/src/app/print-sender.ts Show resolved Hide resolved

simonlabarere and others added 9 commits January 15, 2026 13:18

CCM-14347: Send Print config

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CCM-14347: Send Print config

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CCM-14347: Send Print config

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CCM-14347: Send Print config

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CCM-14347: Send Print config

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CCM-14347: Send Print config

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CCM-14347: Send Print config

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CCM-14347: Send Print config

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Merge branch 'main' into feature/CCM-13475_send_print_events

4ba840b

lapenna-bjss force-pushed the feature/CCM-13475_send_print_events branch from a35e9f1 to 4ba840b Compare January 28, 2026 08:58

CCM-13475: Remove package-lock.json file

abce4d7

lapenna-bjss added 2 commits January 28, 2026 11:44

CCM-13475: Test

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CCM-13475: add input transformation

9fdee7a

nhsd-angel-pastor reviewed Jan 29, 2026

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lapenna-bjss added 3 commits January 29, 2026 16:00

CCM-13475: pin @nhsdigital/nhs-notify-event-schemas-supplier-api to 1…

48d8a4c

….0.6

CCM-13475: add campaignId to letter prepared events

47adec6

CCM-13475: fix linter error

266f4e3

nhsd-angel-pastor reviewed Jan 30, 2026

View reviewed changes

gareth-allan self-assigned this Jan 30, 2026

gareth-allan reviewed Jan 30, 2026

View reviewed changes

-    ]
+    ]
+    condition {
+      test     = "ArnEquals"
+      variable = "aws:SourceArn"
+      values   = [aws_cloudwatch_event_rule.pdf_analysed.arn]
+    }

CCM-13475: Send print events #179

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simonlabarere commented Jan 13, 2026 • edited by lapenna-bjss Loading Uh oh! There was an error while loading. Please reload this page.

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Description

Test evidence

Print Sender logs

Event Bus logs

Type of changes

Checklist

Sensitive Information Declaration

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simonlabarere Jan 15, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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nhsd-angel-pastor Jan 29, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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simonlabarere commented Jan 13, 2026 •

edited by lapenna-bjss

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simonlabarere Jan 15, 2026 •

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nhsd-angel-pastor Jan 29, 2026 •

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