feat(core): add validations for export name in CfnOutput

packages/aws-cdk-lib/cloudformation-include/test/valid-templates.test.ts

@@ -727,7 +727,7 @@ describe('CDK Include', () => {
  const output = cfnTemplate.getOutput('Output1');
  output.value = 'a mutated value';
  output.description = undefined;
- output.exportName = 'an export';
+ output.exportName = 'an-export';
  output.condition = new core.CfnCondition(stack, 'MyCondition', {
  expression: core.Fn.conditionIf('AlwaysFalseCond', core.Aws.NO_VALUE, true),
  });
@@ -755,7 +755,7 @@ describe('CDK Include', () => {
  "Output1": {
  "Value": "a mutated value",
  "Export": {
- "Name": "an export",
+ "Name": "an-export",
  },
  "Condition": "MyCondition",
  },

packages/aws-cdk-lib/core/lib/cfn-output.ts

@@ -178,10 +178,19 @@ export class CfnOutput extends CfnElement {
  }
 
  private validateOutput(): string[] {
- if (this._exportName && !Token.isUnresolved(this._exportName) && this._exportName.length > 255) {
- return [`Export name cannot exceed 255 characters (got ${this._exportName.length} characters)`];
+ const errors: string[] = [];
+ if (this._exportName !== undefined && !Token.isUnresolved(this._exportName)) {
+ if (this._exportName.length === 0) {
+ errors.push('Export name cannot be empty');
+ }
+ if (this._exportName.length > 255) {
+ errors.push(`Export name cannot exceed 255 characters (got ${this._exportName.length} characters)`);
+ }
+ if (!/^[A-Za-z0-9-:]*$/.test(this._exportName)) {
+ errors.push(`Export name must only include alphanumeric characters, colons, or hyphens (got '${this._exportName}')`);
+ }
  }
- return [];
+ return errors;
  }
 }
 

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

@@ -140,7 +140,44 @@ describe('output', () => {
  const errors = output.node.validate();
 
  expect(errors).toEqual([
- expect.stringContaining('Export name cannot exceed 255 characters'),
+ expect.stringContaining('Export name cannot exceed 255 characters (got 260 characters)'),
+ ]);
+ });
+
+ test('Verify zero length of export name', () => {
+ const output = new CfnOutput(stack, 'SomeOutput', { value: 'x', exportName: '' });
+ const errors = output.node.validate();
+
+ expect(errors).toEqual([
+ expect.stringContaining('Export name cannot be empty'),
+ ]);
+ });
+
+ test('throw if export name has invalid strings (space)', () => {
+ const output = new CfnOutput(stack, 'SomeOutput', { value: 'x', exportName: 'SOME INVALID EXPORT NAME' });
+ const errors = output.node.validate();
+
+ expect(errors).toEqual([
+ expect.stringContaining('Export name must only include alphanumeric characters, colons, or hyphens (got \'SOME INVALID EXPORT NAME\''),
+ ]);
+ });
+
+ test('throw if export name has invalid strings (underscore)', () => {
+ const output = new CfnOutput(stack, 'SomeOutput', { value: 'x', exportName: 'SOME_INVALID_EXPORT_NAME' });
+ const errors = output.node.validate();
+
+ expect(errors).toEqual([
+ expect.stringContaining('Export name must only include alphanumeric characters, colons, or hyphens (got \'SOME_INVALID_EXPORT_NAME\''),
+ ]);
+ });
+
+ test('throw if export name exceeds maximum length and has invalid strings', () => {
+ const output = new CfnOutput(stack, 'SomeOutput', { value: 'x', exportName: ' '.repeat(260) });
+ const errors = output.node.validate();
+
+ expect(errors).toEqual([
+ expect.stringContaining('Export name cannot exceed 255 characters (got 260 characters)'),
+ expect.stringContaining(`Export name must only include alphanumeric characters, colons, or hyphens (got '${' '.repeat(260)}'`),
  ]);
  });
 });