fix(assert): support multiline strings with stringLike() (aws#17692)

Updates the `RegExp` constructor to support multiline. Resolves aws#17691

----

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

packages/@aws-cdk/assert-internal/README.md

@@ -103,7 +103,7 @@ The following matchers exist:
   back to exact value matching.
 - `arrayWith(E, [F, ...])` - value must be an array containing the given elements (or matchers) in any order.
 - `stringLike(S)` - value must be a string matching `S`. `S` may contain `*` as wildcard to match any number
-  of characters.
+  of characters. Multiline strings are supported.
 - `anything()` - matches any value.
 - `notMatching(M)` - any value that does NOT match the given matcher (or exact value) given.
 - `encodedJson(M)` - value must be a string which, when decoded as JSON, matches the given matcher or

packages/@aws-cdk/assert-internal/lib/assertions/have-resource-matchers.ts

@@ -239,11 +239,11 @@ function isCallable(x: any): x is ((...args: any[]) => any) {
 }
 
 /**
- * Do a glob-like pattern match (which only supports *s)
+ * Do a glob-like pattern match (which only supports *s). Supports multiline strings.
  */
 export function stringLike(pattern: string): PropertyMatcher {
   // Replace * with .* in the string, escape the rest and brace with ^...$
-  const regex = new RegExp(`^${pattern.split('*').map(escapeRegex).join('.*')}$`);
+  const regex = new RegExp(`^${pattern.split('*').map(escapeRegex).join('.*')}$`, 'm');
 
   return annotateMatcher({ $stringContaining: pattern }, (value: any, failure: InspectionFailure) => {
     if (typeof value !== 'string') {

packages/@aws-cdk/assert-internal/test/have-resource.test.ts

@@ -1,4 +1,14 @@
-import { ABSENT, arrayWith, exactValue, expect as cdkExpect, haveResource, haveResourceLike, Capture, anything } from '../lib/index';
+import {
+  ABSENT,
+  arrayWith,
+  exactValue,
+  expect as cdkExpect,
+  haveResource,
+  haveResourceLike,
+  Capture,
+  anything,
+  stringLike,
+} from '../lib/index';
 import { mkResource, mkStack } from './cloud-artifact';
 
 test('support resource with no properties', () => {
@@ -156,6 +166,30 @@ describe('property absence', () => {
     }).toThrowError(/Array did not contain expected element/);
   });
 
+  test('can use matcher to test stringLike on single-line strings', () => {
+    const synthStack = mkResource({
+      Content: 'something required something',
+    });
+
+    expect(() => {
+      cdkExpect(synthStack).to(haveResource('Some::Resource', {
+        Content: stringLike('*required*'),
+      }));
+    }).not.toThrowError();
+  });
+
+  test('can use matcher to test stringLike on multi-line strings', () => {
+    const synthStack = mkResource({
+      Content: 'something\nrequired\nsomething',
+    });
+
+    expect(() => {
+      cdkExpect(synthStack).to(haveResource('Some::Resource', {
+        Content: stringLike('*required*'),
+      }));
+    }).not.toThrowError();
+  });
+
   test('arrayContaining must match all elements in any order', () => {
     const synthStack = mkResource({
       List: ['a', 'b'],