feat(core): Add ability to set stack description (#4457) (#4477)

* Add description parameter to StackProps

* Test new description StackProp

packages/@aws-cdk/core/lib/stack.ts

@@ -17,6 +17,13 @@ const STACK_SYMBOL = Symbol.for('@aws-cdk/core.Stack');
 const VALID_STACK_NAME_REGEX = /^[A-Za-z][A-Za-z0-9-]*$/;
 
 export interface StackProps {
+  /**
+   * A description of the stack.
+   *
+   * @default - No description.
+   */
+  readonly description?: string;
+
   /**
    * The AWS environment (account/region) where this stack will be deployed.
    *
@@ -211,6 +218,15 @@ export class Stack extends Construct implements ITaggable {
     this.region = region;
     this.environment = environment;
 
+    if (props.description !== undefined) {
+      // Max length 1024 bytes
+      // Typically 2 bytes per character, may be more for more exotic characters
+      if (props.description.length > 512) {
+        throw new Error(`Stack description must be <= 1024 bytes. Received description: '${props.description}'`);
+      }
+      this.templateOptions.description = props.description;
+    }
+
     this._stackName = props.stackName !== undefined ? props.stackName : this.calculateStackName();
     this.tags = new TagManager(TagType.KEY_VALUE, 'aws:cdk:stack', props.tags);
 

packages/@aws-cdk/core/test/test.stack.ts

@@ -116,6 +116,30 @@ export = {
     test.done();
   },
 
+  'Stacks can have a description given to them'(test: Test) {
+    const stack = new Stack(new App(), 'MyStack', { description: 'My stack, hands off!'});
+    const output = toCloudFormation(stack);
+    test.equal(output.Description, 'My stack, hands off!');
+    test.done();
+  },
+
+  'Stack descriptions have a limited length'(test: Test) {
+    const desc = `Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor
+     incididunt ut labore et dolore magna aliqua. Consequat interdum varius sit amet mattis vulputate
+     enim nulla aliquet. At imperdiet dui accumsan sit amet nulla facilisi morbi. Eget lorem dolor sed
+     viverra ipsum. Diam volutpat commodo sed egestas egestas. Sit amet porttitor eget dolor morbi non.
+     Lorem dolor sed viverra ipsum. Id porta nibh venenatis cras sed felis. Augue interdum velit euismod
+     in pellentesque. Suscipit adipiscing bibendum est ultricies integer quis. Condimentum id venenatis a
+     condimentum vitae sapien pellentesque habitant morbi. Congue mauris rhoncus aenean vel elit scelerisque
+     mauris pellentesque pulvinar.
+     Faucibus purus in massa tempor nec. Risus viverra adipiscing at in. Integer feugiat scelerisque varius
+     morbi. Malesuada nunc vel risus commodo viverra maecenas accumsan lacus. Vulputate sapien nec sagittis
+     aliquam malesuada bibendum arcu vitae. Augue neque gravida in fermentum et sollicitudin ac orci phasellus.
+     Ultrices tincidunt arcu non sodales neque sodales.`;
+    test.throws(() => new Stack(new App(), 'MyStack', { description: desc}));
+    test.done();
+  },
+
   'Include should support non-hash top-level template elements like "Description"'(test: Test) {
     const stack = new Stack();