From 2c8283782cca6e29b8c80109ed5ed62ef9e0a6c2 Mon Sep 17 00:00:00 2001
From: go-to-k <24818752+go-to-k@users.noreply.github.com>
Date: Thu, 4 Jan 2024 21:14:30 +0900
Subject: [PATCH 1/5] feat(core): add validation for export name in CfnOutput

---
 packages/aws-cdk-lib/core/lib/cfn-output.ts | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/packages/aws-cdk-lib/core/lib/cfn-output.ts b/packages/aws-cdk-lib/core/lib/cfn-output.ts
index 8f1bf310ddead..ccf8b69f7a031 100644
--- a/packages/aws-cdk-lib/core/lib/cfn-output.ts
+++ b/packages/aws-cdk-lib/core/lib/cfn-output.ts
@@ -178,8 +178,16 @@ 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)`];
+    if (this._exportName !== undefined && !Token.isUnresolved(this._exportName)) {
+      if (this._exportName.length === 0) {
+        return ['Export name cannot be empty'];
+      }
+      if (this._exportName.length > 255) {
+        return [`Export name cannot exceed 255 characters (got ${this._exportName.length} characters)`];
+      }
+      if (!/^[A-Za-z0-9-:]*$/.test(this._exportName)) {
+        return [`Export name must only include alphanumeric characters, colons, or hyphens (got '${this._exportName}')`];
+      }
     }
     return [];
   }

From 5f2912d40396c457376c305e041949852db5f071 Mon Sep 17 00:00:00 2001
From: go-to-k <24818752+go-to-k@users.noreply.github.com>
Date: Thu, 4 Jan 2024 21:27:14 +0900
Subject: [PATCH 2/5] add unit tests

---
 packages/aws-cdk-lib/core/test/output.test.ts | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/packages/aws-cdk-lib/core/test/output.test.ts b/packages/aws-cdk-lib/core/test/output.test.ts
index 335173bd944d4..22b9ce94a1494 100644
--- a/packages/aws-cdk-lib/core/test/output.test.ts
+++ b/packages/aws-cdk-lib/core/test/output.test.ts
@@ -143,4 +143,31 @@ describe('output', () => {
       expect.stringContaining('Export name cannot exceed 255 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 string (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 string (under_bar)', () => {
+    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\''),
+    ]);
+  });
 });

From bc1ddc8d857b2892f7069edd04828b34121c0812 Mon Sep 17 00:00:00 2001
From: go-to-k <24818752+go-to-k@users.noreply.github.com>
Date: Thu, 4 Jan 2024 21:54:45 +0900
Subject: [PATCH 3/5] modify valid-templates.test.ts in
 aws-cdk-lib/cloudformation-include

---
 .../cloudformation-include/test/valid-templates.test.ts       | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/aws-cdk-lib/cloudformation-include/test/valid-templates.test.ts b/packages/aws-cdk-lib/cloudformation-include/test/valid-templates.test.ts
index 3ed846172ac11..b6ff1bea6f681 100644
--- a/packages/aws-cdk-lib/cloudformation-include/test/valid-templates.test.ts
+++ b/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",
         },

From 62b2f74779ced8efc2ac9da43383cd7db2b487ae Mon Sep 17 00:00:00 2001
From: go-to-k <24818752+go-to-k@users.noreply.github.com>
Date: Fri, 5 Jan 2024 12:03:53 +0900
Subject: [PATCH 4/5] change logic

---
 packages/aws-cdk-lib/core/lib/cfn-output.ts   |  9 +++++----
 packages/aws-cdk-lib/core/test/output.test.ts | 16 +++++++++++++---
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/packages/aws-cdk-lib/core/lib/cfn-output.ts b/packages/aws-cdk-lib/core/lib/cfn-output.ts
index ccf8b69f7a031..b0bb1cb38ef63 100644
--- a/packages/aws-cdk-lib/core/lib/cfn-output.ts
+++ b/packages/aws-cdk-lib/core/lib/cfn-output.ts
@@ -178,18 +178,19 @@ export class CfnOutput extends CfnElement {
   }
 
   private validateOutput(): string[] {
+    const errors: string[] = [];
     if (this._exportName !== undefined && !Token.isUnresolved(this._exportName)) {
       if (this._exportName.length === 0) {
-        return ['Export name cannot be empty'];
+        errors.push('Export name cannot be empty');
       }
       if (this._exportName.length > 255) {
-        return [`Export name cannot exceed 255 characters (got ${this._exportName.length} characters)`];
+        errors.push(`Export name cannot exceed 255 characters (got ${this._exportName.length} characters)`);
       }
       if (!/^[A-Za-z0-9-:]*$/.test(this._exportName)) {
-        return [`Export name must only include alphanumeric characters, colons, or hyphens (got '${this._exportName}')`];
+        errors.push(`Export name must only include alphanumeric characters, colons, or hyphens (got '${this._exportName}')`);
       }
     }
-    return [];
+    return errors;
   }
 }
 
diff --git a/packages/aws-cdk-lib/core/test/output.test.ts b/packages/aws-cdk-lib/core/test/output.test.ts
index 22b9ce94a1494..94a4eec333beb 100644
--- a/packages/aws-cdk-lib/core/test/output.test.ts
+++ b/packages/aws-cdk-lib/core/test/output.test.ts
@@ -140,7 +140,7 @@ 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)'),
     ]);
   });
 
@@ -153,7 +153,7 @@ describe('output', () => {
     ]);
   });
 
-  test('throw if export name has invalid string (space)', () => {
+  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();
 
@@ -162,7 +162,7 @@ describe('output', () => {
     ]);
   });
 
-  test('throw if export name has invalid string (under_bar)', () => {
+  test('throw if export name has invalid strings (under_bar)', () => {
     const output = new CfnOutput(stack, 'SomeOutput', { value: 'x', exportName: 'SOME_INVALID_EXPORT_NAME' });
     const errors = output.node.validate();
 
@@ -170,4 +170,14 @@ describe('output', () => {
       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)}'`),
+    ]);
+  });
 });

From 29144aef1e7df16d414f04b9e07984be2bb49581 Mon Sep 17 00:00:00 2001
From: "k.goto" <24818752+go-to-k@users.noreply.github.com>
Date: Sat, 6 Jan 2024 01:28:45 +0900
Subject: [PATCH 5/5] Update packages/aws-cdk-lib/core/test/output.test.ts

---
 packages/aws-cdk-lib/core/test/output.test.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/aws-cdk-lib/core/test/output.test.ts b/packages/aws-cdk-lib/core/test/output.test.ts
index 94a4eec333beb..57507edcd9fb6 100644
--- a/packages/aws-cdk-lib/core/test/output.test.ts
+++ b/packages/aws-cdk-lib/core/test/output.test.ts
@@ -162,7 +162,7 @@ describe('output', () => {
     ]);
   });
 
-  test('throw if export name has invalid strings (under_bar)', () => {
+  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();