fix(core): Add stage prefix to stack name shortening process (#24443)

There is an issue in the stack name generation process where the prefix generated from assembly's stage name is not taken into account when shortening a stack name to meet the requirement of being equal or less than 128 characters longs.

This can lead to generating an invalid stack name greater than 128 characters: since the stack name is shortened to 128 characters, when the prefix is added, the limit is exceeded.

Current solution:
- Add the prefix into the first ID if any prefix is present.

Alternative solution:
- Add the prefix at the start of the ID list. Doing this would require to add more conditionals and consider more corner cases to keep the names consistent with the old algorithm.
 

Fixes #23628

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: QustodioPablo

packages/aws-cdk-lib/core/lib/private/unique-resource-name.ts

@@ -25,6 +25,13 @@ interface MakeUniqueResourceNameOptions {
    * @default - none
    */
   readonly allowedSpecialCharacters?: string;
+
+  /**
+   * Prefix to be added into the stack name
+   *
+   * @default - none
+   */
+  readonly prefix?: string;
 }
 
 /**
@@ -49,6 +56,7 @@ const HASH_LEN = 8;
 export function makeUniqueResourceName(components: string[], options: MakeUniqueResourceNameOptions) {
   const maxLength = options.maxLength ?? 256;
   const separator = options.separator ?? '';
+  const prefix = options.prefix ?? '';
   components = components.filter(x => x !== HIDDEN_ID);
 
   if (components.length === 0) {
@@ -59,7 +67,7 @@ export function makeUniqueResourceName(components: string[], options: MakeUnique
   // in order to support transparent migration of cloudformation templates to the CDK without the
   // need to rename all resources.
   if (components.length === 1) {
-    const topLevelResource = removeNonAllowedSpecialCharacters(components[0], separator, options.allowedSpecialCharacters);
+    const topLevelResource = prefix + removeNonAllowedSpecialCharacters(components[0], separator, options.allowedSpecialCharacters);
 
     if (topLevelResource.length <= maxLength) {
       return topLevelResource;
@@ -68,6 +76,9 @@ export function makeUniqueResourceName(components: string[], options: MakeUnique
 
   // Calculate the hash from the full path, included unresolved tokens so the hash value is always unique
   const hash = pathHash(components);
+  if (prefix) {
+    components.unshift(prefix);
+  }
   const human = removeDupes(components)
     .filter(pathElement => pathElement !== HIDDEN_FROM_HUMAN_ID)
     .map(pathElement => removeNonAllowedSpecialCharacters(pathElement, separator, options.allowedSpecialCharacters))

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

@@ -1424,7 +1424,7 @@ export class Stack extends Construct implements ITaggable {
   private generateStackName() {
     const assembly = Stage.of(this);
     const prefix = (assembly && assembly.stageName) ? `${assembly.stageName}-` : '';
-    return `${prefix}${this.generateStackId(assembly)}`;
+    return `${this.generateStackId(assembly, prefix)}`;
   }
 
   /**
@@ -1439,7 +1439,7 @@ export class Stack extends Construct implements ITaggable {
   /**
    * Generate an ID with respect to the given container construct.
    */
-  private generateStackId(container: IConstruct | undefined) {
+  private generateStackId(container: IConstruct | undefined, prefix: string='') {
     const rootPath = rootPathTo(this, container);
     const ids = rootPath.map(c => Node.of(c).id);
 
@@ -1449,7 +1449,7 @@ export class Stack extends Construct implements ITaggable {
       throw new Error('unexpected: stack id must always be defined');
     }
 
-    return makeStackName(ids);
+    return makeStackName(ids, prefix);
   }
 
   private resolveExportedValue(exportedValue: any): ResolvedExport {
@@ -1635,9 +1635,14 @@ export function rootPathTo(construct: IConstruct, ancestor?: IConstruct): IConst
  * has only one component. Otherwise we fall back to the regular "makeUniqueId"
  * behavior.
  */
-function makeStackName(components: string[]) {
-  if (components.length === 1) { return components[0]; }
-  return makeUniqueResourceName(components, { maxLength: 128 });
+function makeStackName(components: string[], prefix: string='') {
+  if (components.length === 1) {
+    const stack_name = prefix + components[0];
+    if (stack_name.length <= 128) {
+      return stack_name;
+    }
+  }
+  return makeUniqueResourceName(components, { maxLength: 128, prefix: prefix });
 }
 
 function getCreateExportsScope(stack: Stack) {

packages/aws-cdk-lib/core/test/stage.test.ts

@@ -103,6 +103,17 @@ describe('stage', () => {
     expect(stack.stackName).toEqual('MyStage-MyStack');
   });
 
+  test('generated stack names will not exceed 128 characters', () => {
+    // WHEN
+    const app = new App();
+    const stage = new Stage(app, 'ThisStageNameIsVeryLongButWillOnlyBeTooLongWhenCombinedWithTheStackName');
+    const stack = new BogusStack(stage, 'ThisStackNameIsVeryLongButItWillOnlyBeTooLongWhenCombinedWithTheLongPrefix');
+
+    // THEN
+    expect(stack.stackName.length).toEqual(128);
+    expect(stack.stackName).toEqual('ThisStageNameIsVeryLongButWillOnlyBeTooLongWhenCombinedWithTsVeryLongButItWillOnlyBeTooLongWhenCombinedWithTheLongPrefix4CA9F65B');
+  });
+
   test('Can not have dependencies to stacks outside the nested asm', () => {
     // GIVEN
     const app = new App();