feat: add s3-bucket and s3-prefix inputs for large template upload (#196)

* feat: add s3-bucket and s3-prefix inputs for large template upload (#180)

When s3-bucket is provided, the action uploads the local template file
to S3 and uses TemplateURL instead of TemplateBody, avoiding the
51,200 byte inline template limit.

Closes #180

* chore: rebuild dist

Author: kddejong

__tests__/main.test.ts

@@ -13,6 +13,7 @@ import {
   ExecuteChangeSetCommand,
   DescribeStacksCommand
 } from '@aws-sdk/client-cloudformation'
+import { S3Client, PutObjectCommand } from '@aws-sdk/client-s3'
 import { mockClient } from 'aws-sdk-client-mock'
 import { FileHandle } from 'fs/promises'
 import 'aws-sdk-client-mock-jest'
@@ -60,6 +61,7 @@ const mockStackId =
   'arn:aws:cloudformation:us-east-1:123456789012:stack/myteststack/466df9e0-0dff-08e3-8e2f-5088487c4896'
 
 const mockCfnClient = mockClient(CloudFormationClient)
+const mockS3Client = mockClient(S3Client)
 
 // Helper function to create complete inputs
 const createInputs = (overrides: Partial<Inputs> = {}): Inputs => ({
@@ -81,6 +83,8 @@ const createInputs = (overrides: Partial<Inputs> = {}): Inputs => ({
   'change-set-name': '',
   'include-nested-stacks-change-set': '0',
   'deployment-mode': '',
+  's3-bucket': '',
+  's3-prefix': '',
   'execute-change-set-id': '',
   ...overrides
 })
@@ -135,17 +139,15 @@ describe('Deploy CloudFormation Stack', () => {
         }
       )
 
+    mockS3Client.reset().on(PutObjectCommand).resolves({})
+
     mockCfnClient
       .reset()
       .on(CreateChangeSetCommand)
       .resolves({
         StackId: mockStackId
       })
       .on(CreateChangeSetCommand)
-      .resolves({
-        StackId: mockStackId
-      })
-      .on(CreateChangeSetCommand)
       .resolves({})
       .on(DescribeChangeSetCommand)
       .resolves({
@@ -1554,4 +1556,73 @@ describe('Deploy CloudFormation Stack', () => {
     expect(core.setOutput).toHaveBeenCalledWith('has-changes', 'false')
     expect(core.setOutput).toHaveBeenCalledWith('changes-count', '0')
   })
+
+  test('uploads template to S3 when s3-bucket is provided', async () => {
+    const inputs = createInputs({
+      's3-bucket': 'my-deploy-bucket'
+    })
+
+    jest.spyOn(core, 'getInput').mockImplementation((name: string) => {
+      return inputs[name]
+    })
+
+    await run()
+
+    expect(core.setFailed).toHaveBeenCalledTimes(0)
+    expect(mockS3Client).toHaveReceivedCommandTimes(PutObjectCommand, 1)
+    expect(mockS3Client).toHaveReceivedCommandWith(PutObjectCommand, {
+      Bucket: 'my-deploy-bucket',
+      Key: 'template.yaml',
+      Body: mockTemplate
+    })
+    expect(mockCfnClient).toHaveReceivedCommandWith(CreateChangeSetCommand, {
+      StackName: 'MockStack',
+      TemplateURL: 'https://my-deploy-bucket.s3.amazonaws.com/template.yaml',
+      TemplateBody: undefined
+    })
+  })
+
+  test('uploads template to S3 with prefix when s3-prefix is provided', async () => {
+    const inputs = createInputs({
+      's3-bucket': 'my-deploy-bucket',
+      's3-prefix': 'cfn-templates'
+    })
+
+    jest.spyOn(core, 'getInput').mockImplementation((name: string) => {
+      return inputs[name]
+    })
+
+    await run()
+
+    expect(core.setFailed).toHaveBeenCalledTimes(0)
+    expect(mockS3Client).toHaveReceivedCommandTimes(PutObjectCommand, 1)
+    expect(mockS3Client).toHaveReceivedCommandWith(PutObjectCommand, {
+      Bucket: 'my-deploy-bucket',
+      Key: 'cfn-templates/template.yaml',
+      Body: mockTemplate
+    })
+    expect(mockCfnClient).toHaveReceivedCommandWith(CreateChangeSetCommand, {
+      StackName: 'MockStack',
+      TemplateURL:
+        'https://my-deploy-bucket.s3.amazonaws.com/cfn-templates/template.yaml',
+      TemplateBody: undefined
+    })
+  })
+
+  test('does not upload to S3 when template is a URL', async () => {
+    const inputs = createInputs({
+      template:
+        'https://s3.amazonaws.com/templates/myTemplate.template?versionId=123ab1cdeKdOW5IH4GAcYbEngcpTJTDW',
+      's3-bucket': 'my-deploy-bucket'
+    })
+
+    jest.spyOn(core, 'getInput').mockImplementation((name: string) => {
+      return inputs[name]
+    })
+
+    await run()
+
+    expect(core.setFailed).toHaveBeenCalledTimes(0)
+    expect(mockS3Client).toHaveReceivedCommandTimes(PutObjectCommand, 0)
+  })
 })

action.yml

@@ -66,6 +66,12 @@ inputs:
   execute-change-set-id:
     description: "Execute an existing change set by ID or name instead of creating a new one. When provided, only 'name' (stack name) is required."
     required: false
+  s3-bucket:
+    description: "The name of the S3 bucket where the template will be uploaded before creating the change set. When provided, the template file is uploaded to S3 and TemplateURL is used instead of TemplateBody, avoiding the 51,200 byte inline limit."
+    required: false
+  s3-prefix:
+    description: "A prefix to use for the S3 object key when uploading the template. The final key will be '<s3-prefix>/<template-filename>'. Defaults to no prefix."
+    required: false
   deployment-mode:
     description: "The deployment mode for the change set. Use 'REVERT_DRIFT' to create a change set that reverts drift. Defaults to standard deployment."
     required: false

dist/579.index.js

@@ -58,9 +58,13 @@ class EventStreamSerde {
                     body: event.body,
                 };
             }
-            const unionMember = Object.keys(event).find((key) => {
-                return key !== "__type";
-            }) ?? "";
+            let unionMember = "";
+            for (const key in event) {
+                if (key !== "__type") {
+                    unionMember = key;
+                    break;
+                }
+            }
             const { additionalHeaders, body, eventType, explicitPayloadContentType } = this.writeEventBody(unionMember, unionSchema, event);
             const headers = {
                 ":event-type": { type: "string", value: eventType },
@@ -81,9 +85,13 @@ class EventStreamSerde {
         const memberSchemas = unionSchema.getMemberSchemas();
         const initialResponseMarker = Symbol("initialResponseMarker");
         const asyncIterable = marshaller.deserialize(response.body, async (event) => {
-            const unionMember = Object.keys(event).find((key) => {
-                return key !== "__type";
-            }) ?? "";
+            let unionMember = "";
+            for (const key in event) {
+                if (key !== "__type") {
+                    unionMember = key;
+                    break;
+                }
+            }
             const body = event[unionMember].body;
             if (unionMember === "initial-response") {
                 const dataObject = await this.deserializer.read(responseSchema, body);
@@ -159,8 +167,8 @@ class EventStreamSerde {
             if (!responseSchema) {
                 throw new Error("@smithy::core/protocols - initial-response event encountered in event stream but no response schema given.");
             }
-            for (const [key, value] of Object.entries(firstEvent.value)) {
-                initialResponseContainer[key] = value;
+            for (const key in firstEvent.value) {
+                initialResponseContainer[key] = firstEvent.value[key];
             }
         }
         return {