fix(assert): CfnParameter MatchStyle diff support (#3408)

* `NO_REPLACES` now verifies that no parameters are updated
* `SUPERSET` now verifies that no parameters are added

Fixes #3399

Author: nmussy

packages/@aws-cdk/assert/lib/assertions/match-template.ts

@@ -62,12 +62,22 @@ class StackMatchesTemplateAssertion extends Assertion<StackInspector> {
         if (change.changeImpact === cfnDiff.ResourceImpact.MAY_REPLACE) { return false; }
         if (change.changeImpact === cfnDiff.ResourceImpact.WILL_REPLACE) { return false; }
       }
+
+      for (const key of Object.keys(diff.parameters.changes)) {
+        const change = diff.parameters.changes[key]!;
+        if (change.isUpdate) { return false; }
+      }
       return true;
     case MatchStyle.SUPERSET:
       for (const key of Object.keys(diff.resources.changes)) {
         const change = diff.resources.changes[key]!;
         if (change.changeImpact !== cfnDiff.ResourceImpact.WILL_CREATE) { return false; }
       }
+
+      for (const key of Object.keys(diff.parameters.changes)) {
+        const change = diff.parameters.changes[key]!;
+        if (change.isAddition) { return false; }
+      }
       return true;
     }
     throw new Error(`Unsupported match style: ${this.matchStyle}`);

packages/@aws-cdk/assert/test/test.assertions.ts

@@ -82,6 +82,31 @@ passingExample('sugar for matching stack to a template', () => {
     }
   });
 });
+passingExample('expect <synthStack> to match (no replaces) <template> with parameters', () => {
+  const parameterType = 'Test::Parameter';
+  const synthStack = synthesizedStack(stack => {
+    new TestParameter(stack, 'TestParameter', { type: parameterType });
+  });
+  const expected = {};
+  expect(synthStack).to(matchTemplate(expected, MatchStyle.NO_REPLACES));
+});
+passingExample('expect <synthStack> to be a superset of <template> with parameters', () => {
+  const parameterType = 'Test::Parameter';
+  const synthStack = synthesizedStack(stack => {
+    // Added
+    new TestResource(stack, 'NewResource', { type: 'AWS::S3::Bucket' });
+    // Expected
+    new TestParameter(stack, 'TestParameterA', {type: parameterType});
+    new TestParameter(stack, 'TestParameterB', {type: parameterType, default: { Foo: 'Bar' } });
+  });
+  const expected = {
+    Parameters: {
+      TestParameterA: { Type: 'Test::Parameter' },
+      TestParameterB: { Type: 'Test::Parameter', Default: { Foo: 'Bar' } }
+    }
+  };
+  expect(synthStack).to(matchTemplate(expected, MatchStyle.SUPERSET));
+});
 
 failingExample('expect <synthStack> at <some path> *not* to have <some type>', () => {
   const resourceType = 'Test::Resource';
@@ -146,6 +171,36 @@ failingExample('expect <synthStack> to be a superset of <template>', () => {
   };
   expect(synthStack).to(matchTemplate(expected, MatchStyle.SUPERSET));
 });
+failingExample('expect <synthStack> to match (no replaces) <template> with parameters', () => {
+  const parameterType = 'Test::Parameter';
+  const synthStack = synthesizedStack(stack => {
+    new TestParameter(stack, 'TestParameter', { type: parameterType });
+  });
+  const expected = {
+    Parameters: {
+      TestParameter: { Type: 'AWS::S3::Bucket' }
+    }
+  };
+  expect(synthStack).to(matchTemplate(expected, MatchStyle.NO_REPLACES));
+});
+failingExample('expect <synthStack> to be a superset of <template> with parameters', () => {
+  const parameterType = 'Test::Parameter';
+  const synthStack = synthesizedStack(stack => {
+    // Added
+    new TestParameter(stack, 'NewParameter', { type: 'AWS::S3::Bucket' });
+    // Expected
+    new TestParameter(stack, 'TestParameterA', { type: parameterType });
+    // Expected, but has different properties - will break
+    new TestParameter(stack, 'TestParameterB', { type: parameterType, default: { Foo: 'Bar' } });
+  });
+  const expected = {
+    Parameters: {
+      TestParameterA: { Type: 'Test::Parameter' },
+      TestParameterB: { Type: 'Test::Parameter', Default: { Foo: 'Baz' } }
+    }
+  };
+  expect(synthStack).to(matchTemplate(expected, MatchStyle.SUPERSET));
+});
 
 // countResources
 
@@ -222,3 +277,13 @@ class TestResource extends cdk.CfnResource {
     super(scope, id, props);
   }
 }
+
+interface TestParameterProps extends cdk.CfnParameterProps {
+  type: string;
+}
+
+class TestParameter extends cdk.CfnParameter {
+  constructor(scope: cdk.Construct, id: string, props: TestParameterProps) {
+    super(scope, id, props);
+  }
+}

packages/@aws-cdk/aws-autoscaling/test/test.scheduled-action.ts

@@ -96,6 +96,12 @@ export = {
           },
         }
       },
+      Parameters: {
+        SsmParameterValueawsserviceamiamazonlinuxlatestamznamihvmx8664gp2C96584B6F00A464EAD1953AFF4B05118Parameter: {
+          Type: "AWS::SSM::Parameter::Value<String>",
+          Default: "/aws/service/ami-amazon-linux-latest/amzn-ami-hvm-x86_64-gp2"
+        }
+      }
     }, MatchStyle.SUPERSET);
 
     test.done();