From 5249624a59375a2876b0f777f5db112d18cb3cc8 Mon Sep 17 00:00:00 2001
From: will wade <willwade@gmail.com>
Date: Tue, 18 Aug 2026 09:27:04 +0000
Subject: [PATCH] =?UTF-8?q?fix(azure):=20emit=20<bookmark>=20instead=20of?=
 =?UTF-8?q?=20W3C=20<mark>=20=E2=80=94=20Azure=20silently=20synthesises=20?=
 =?UTF-8?q?no=20audio=20for=20<mark>?=
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Azure's Speech service does not support the SSML <mark> element: an
utterance containing one completes normally but synthesises zero
audio, with no error from the service (verified live against the
Azure-family Edge endpoint). Azure's documented equivalent is
<bookmark mark="…"/>, delivered as a Bookmark synthesis event.

The MicrosoftAzure formatter now maps [mark: "x"] to
<bookmark mark="x"/>. Other platforms are unchanged.
---
 src/formatters/ssml/microsoft_azure.rs | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/formatters/ssml/microsoft_azure.rs b/src/formatters/ssml/microsoft_azure.rs
index 0d60f16..219e88a 100644
--- a/src/formatters/ssml/microsoft_azure.rs
+++ b/src/formatters/ssml/microsoft_azure.rs
@@ -215,6 +215,15 @@ impl MicrosoftAzureSsmlFormatter {
         match node.node_type {
             NodeType::PlainText => Ok(node.text.clone()),
             NodeType::TextModifier => self.format_azure_text_modifier(node),
+            // Azure's Speech service does not support the W3C SSML <mark>
+            // element: an utterance containing one synthesises zero audio,
+            // with no error from the service. Its documented equivalent is
+            // <bookmark mark="…"/> (fired as a Bookmark event instead of a
+            // named position).
+            NodeType::Mark => Ok(format!(
+                "<bookmark mark=\"{}\"/>",
+                self.base.escape_xml(&node.text)
+            )),
             _ => self.base.format_node_internal(node),
         }
     }
@@ -447,6 +456,23 @@ mod tests {
         assert!(result.is_ok());
     }
 
+    #[test]
+    fn test_microsoft_azure_mark_emits_bookmark() {
+        // Azure has no W3C <mark> (it silently synthesises zero audio);
+        // the documented equivalent is <bookmark mark="…"/>.
+        let input = "A [mark: \"b1\"] in the text.";
+        let result =
+            SpeechMarkdownParser::to_ssml(input, crate::formatters::base::Platform::MicrosoftAzure);
+        assert!(result.is_ok());
+
+        let ssml = result.unwrap();
+        assert!(ssml.contains("<bookmark mark=\"b1\"/>"), "got: {ssml}");
+        assert!(
+            !ssml.contains("<mark"),
+            "W3C mark must not be emitted: {ssml}"
+        );
+    }
+
     #[test]
     fn test_microsoft_azure_with_section() {
         let input = "#[angry] I am angry!";