fix(VAPI-4457): scope SSML un-escape to SpeakSentence text

models/bxml/Root.ts

@@ -3,6 +3,14 @@ import { XMLBuilder, XMLWriterOptions } from 'xmlbuilder2/lib/interfaces';
 import { Verb } from './Verb';
 
 export const SSML_REGEX = /<([a-zA-Z\/\/].*?)>/g;
+const SPEAK_SENTENCE_REGEX = /(<SpeakSentence\b[^>]*(?<!\/)>)([\s\S]*?)(<\/SpeakSentence>)/g;
+
+/**
+ * Restore SSML tags inside SpeakSentence text content only.
+ * Attribute values and all other elements keep their XML escaping.
+ */
+export const unescapeSsml = (bxml: string): string =>
+    bxml.replace(SPEAK_SENTENCE_REGEX, (_m, open, text, close) => open + text.replace(SSML_REGEX, '<$1>') + close);
 
 /**
  * @export
@@ -54,6 +62,6 @@ export class Root {
      * @param options XML Serialization options
      */
     toBxml(options?: XMLWriterOptions): string {
-        return this.generateXml().end(options).replace(SSML_REGEX, '<$1>');
+        return unescapeSsml(this.generateXml().end(options));
     }
 }

models/bxml/verbs/Gather.ts

@@ -1,7 +1,7 @@
 import { NestableVerb } from '../NestableVerb';
 import { PlayAudio } from './PlayAudio';
 import { SpeakSentence } from './SpeakSentence';
-import { SSML_REGEX } from '../Root';
+import { unescapeSsml } from '../Root';
 import { XMLWriterOptions } from 'xmlbuilder2/lib/interfaces';
 
 type AudioVerbs = Array<PlayAudio | SpeakSentence>;
@@ -54,7 +54,7 @@ export class Gather extends NestableVerb {
      * @param options XML Serialization options
      */
     toBxml(options?: XMLWriterOptions): string {
-        return this.generateXml().toString(options).replace(SSML_REGEX, '<$1>');
+        return unescapeSsml(this.generateXml().toString(options));
     }
 
     /**

models/bxml/verbs/SpeakSentence.ts

@@ -1,6 +1,6 @@
 import { Verb } from '../Verb';
 import { XMLWriterOptions } from 'xmlbuilder2/lib/interfaces';
-import { SSML_REGEX } from '../Root';
+import { unescapeSsml } from '../Root';
 
 export interface SpeakSentenceAttributes {
     voice?: string;
@@ -32,6 +32,6 @@ export class SpeakSentence extends Verb {
      * @param options XML Serialization options
      */
     toBxml(options?: XMLWriterOptions): string {
-        return this.generateXml().toString(options).replace(SSML_REGEX, '<$1>');
+        return unescapeSsml(this.generateXml().toString(options));
     }
 }

tests/unit/models/bxml/Response.test.ts

@@ -1,6 +1,8 @@
 import { Response } from '../../../../models/bxml/Response';
 import { PauseRecording } from '../../../../models/bxml/verbs/PauseRecording';
 import { Root } from '../../../../models/bxml/Root';
+import { Redirect } from '../../../../models/bxml/verbs/Redirect';
+import { SpeakSentence } from '../../../../models/bxml/verbs/SpeakSentence';
 
 describe('Response', () => {
     const pauseRecording = new PauseRecording();
@@ -43,4 +45,22 @@ describe('Response', () => {
 
         expect(response.toBxml()).toBe(expected);
     });
+    describe('SSML un-escaping', () => {
+        test('should keep attribute values escaped in a Response', () => {
+            const redirect = new Redirect({ redirectUrl: 'https://example.com/?info=<https://cert.example.com/cert.pem>' });
+            const bxml = new Response(redirect).toBxml();
+
+            expect(bxml).toContain('info=&lt;https://cert.example.com/cert.pem&gt;');
+            expect(bxml).not.toContain('info=<https');
+        });
+
+        test('should un-escape SSML in SpeakSentence text but not in sibling attributes', () => {
+            const redirect = new Redirect({ redirectUrl: 'https://example.com/?info=<https://cert.example.com/cert.pem>' });
+            const speak = new SpeakSentence('hi <break time="1s"/> there');
+            const bxml = new Response([redirect, speak]).toBxml();
+
+            expect(bxml).toContain('info=&lt;https://cert.example.com/cert.pem&gt;');
+            expect(bxml).toContain('hi <break time="1s"/> there');
+        });
+    });
 });

tests/unit/models/bxml/verbs/Gather.test.ts

@@ -65,4 +65,11 @@ describe('Gather', () => {
         gather.addAudioVerbs(playAudio);
         expect(gather.toBxml()).toBe(expected);
     });
+
+    test('should un-escape SSML in a Gather SpeakSentence but not in Gather attributes', () => {
+        const gather = new Gather({ gatherUrl: 'https://example.com/?a=<b>' }, [new SpeakSentence('say <emphasis>this</emphasis>')]);
+        const expected = '<Gather gatherUrl="https://example.com/?a=&lt;b&gt;"><SpeakSentence>say <emphasis>this</emphasis></SpeakSentence></Gather>';
+
+        expect(gather.toBxml()).toBe(expected);
+    });
 });