output messed up when cdns buffering the response data

[lictex]

some cdn providers could buffer the response data, which might potentially affect sse response parsing.

looks like there s already some code handling this...

https://github.com/google/adk-web/blob/aebc8591ac27bf08d1b9ccf641ad9c8a5a05826d/src/app/core/services/agent.service.ts#L78-L96

but that actually behaves weird. if more than one line is received, obviously only the last line could be incomplete. when the last line throws a SyntaxError, all previous lines have already been successfully looped over and processed. in this case lastData wont be cleared, so when the next data arrives, those lines will be processed again and again.

---

relying on trailing linebreaks is better than errors imo.

diff --git a/src/app/core/services/agent.service.ts b/src/app/core/services/agent.service.ts
index 0d0791a..1fc1418 100644
--- a/src/app/core/services/agent.service.ts
+++ b/src/app/core/services/agent.service.ts
@@ -76,22 +76,15 @@ export class AgentService {
                     return observer.complete();
                   }
                   const chunk = decoder.decode(value, {stream: true});
-                  lastData += chunk;
-                  try {
-                    const lines = lastData.split(/\r?\n/).filter(
-                        (line) => line.startsWith('data:'));
-                    lines.forEach((line) => {
+                  lastData += chunk.replace(/\r/, '');
+                  const lines = lastData.split("\n");
+                  if (lines.length > 1) {
+                    lines.slice(0, -1).filter(line => line.startsWith('data:')).forEach(line => {
                       const data = line.replace(/^data:\s*/, '');
                       JSON.parse(data);
                       self.zone.run(() => observer.next(data));
-                    });
-                    lastData = '';
-                  } catch (e) {
-                    // the data is not a valid json, it could be an incomplete
-                    // chunk. we ignore it and wait for the next chunk.
-                    if (e instanceof SyntaxError) {
-                      read();
-                    }
+                    })
+                    lastData = lines.at(-1)!;
                   }
                   read();  // Read the next chunk
                 })