FIXUP: rework error handling

test/common/bidi.py

@@ -173,9 +173,15 @@ async def ws_reader(self, ws: aiohttp.client.ClientWebSocketResponse) -> None:
                     log_proto.debug("ws_reader: resolving pending command %i", data["id"])
                     if data["type"] == "success":
                         self.pending_commands[data["id"]].set_result(data["result"])
+                    elif data["type"] == "exception":
+                        self.pending_commands[data["id"]].set_exception(
+                            WebdriverError(data["exceptionDetails"]["text"]))
+                    elif data["type"] == "error":
+                        self.pending_commands[data["id"]].set_exception(
+                            WebdriverError(f"{data['error']}: {data.get('message', '')}"))
                     else:
                         self.pending_commands[data["id"]].set_exception(
-                            WebdriverError(f"{data['type']}: {data['message']}"))
+                            WebdriverError(f"unknown response type: {data!r}"))
                     del self.pending_commands[data["id"]]
                     continue
 

test/common/testlib.py

@@ -301,10 +301,10 @@ def kill(self) -> None:
     def bidi(self, method: str, **params: Any) -> JsonObject:
         """Send a Webdriver BiDi command and return the JSON response"""
 
-        res = asyncio.run_coroutine_threadsafe(self.driver.bidi(method, **params), self.loop).result()
-        if res.get("type") == "exception":
-            raise Error(res["exceptionDetails"]["text"])
-        return res
+        try:
+            return asyncio.run_coroutine_threadsafe(self.driver.bidi(method, **params), self.loop).result()
+        except bidi.WebdriverError as e:
+            raise Error(str(e)) from None
 
     def cdp_command(self, method: str, **params: Any) -> JsonObject:
         """Send a Chrome DevTools Protocol command and return the JSON response"""
@@ -753,11 +753,6 @@ def wait_js_cond(self, cond: str, error_description: str = "null") -> None:
                           awaitPromise=True, target={"context": self.driver.context})
                 return
             except Error as e:
-                # rewrite exception to have more context, also for compatibility with existing naughties
-                if "condition did not become true" in e.msg:
-                    raise Error(f"timeout\nwait_js_cond({cond}): {e.msg}") from None
-                raise
-            except bidi.WebdriverError as e:
                 # can happen when waiting across page reloads
                 if (
                     # during page loading
@@ -770,8 +765,12 @@ def wait_js_cond(self, cond: str, error_description: str = "null") -> None:
                    ):
                     sys.stderr.write("wait_js_cond: Ignoring/retrying %r" % e)
                     time.sleep(1)
-                else:
-                    raise
+                    continue
+
+                # rewrite exception to have more context, also for compatibility with existing naughties
+                if "condition did not become true" in e.msg:
+                    raise Error(f"timeout\nwait_js_cond({cond}): {e.msg}") from None
+                raise
 
     def wait_js_func(self, func: str, *args: object) -> None:
         self.wait_js_cond("%s(%s)" % (func, ','.join(map(jsquote, args))))
@@ -1163,22 +1162,26 @@ def snapshot(self, title: str, label: str | None = None) -> None:
         """
         if self.valid:
             filename = unique_filename(f"{label or self.label}-{title}", "png")
-            ret = self.bidi("browsingContext.captureScreenshot", quiet=True, context=self.driver.top_context, origin="document")
-            if "data" in ret:
+            try:
+                ret = self.bidi("browsingContext.captureScreenshot", quiet=True,
+                                context=self.driver.top_context, origin="document")
                 with open(filename, 'wb') as f:
                     f.write(base64.standard_b64decode(ret["data"]))
                 attach(filename, move=True)
                 print("Wrote screenshot to " + filename)
-            else:
-                print("Screenshot not available")
+            except Error as e:
+                print("Screenshot not available:", e)
 
             filename = unique_filename(f"{label or self.label}-{title}", "html")
-            html = self.bidi("script.evaluate", expression="document.documentElement.outerHTML",
-                             quiet=True, awaitPromise=False, target={"context": self.driver.context})
-            with open(filename, 'wb') as f:
-                f.write(html["result"]["value"].encode())
-            attach(filename, move=True)
-            print("Wrote HTML dump to " + filename)
+            try:
+                html = self.bidi("script.evaluate", expression="document.documentElement.outerHTML",
+                                 quiet=True, awaitPromise=False, target={"context": self.driver.context})
+                with open(filename, 'wb') as f:
+                    f.write(html["result"]["value"].encode())
+                attach(filename, move=True)
+                print("Wrote HTML dump to " + filename)
+            except Error as e:
+                print("HTML dump not available:", e)
 
     def _set_window_size(self, width: int, height: int) -> None:
         self.bidi("browsingContext.setViewport", context=self.driver.top_context,
@@ -2179,7 +2182,7 @@ def snapshot(self, title: str, label: str | None = None) -> None:
         if self.browser is not None:
             try:
                 self.browser.snapshot(title, label)
-            except RuntimeError:
+            except Error:
                 # this usually runs in exception handlers; raising an exception here skips cleanup handlers, so don't
                 sys.stderr.write("Unexpected exception in snapshot():\n")
                 sys.stderr.write(traceback.format_exc())