fix: bedrock exception could be found at end of a stream (#2654)

lua/avante/providers/bedrock.lua

@@ -79,6 +79,16 @@ function M:build_bedrock_payload(prompt_opts, request_body)
   return model_handler.build_bedrock_payload(self, prompt_opts, request_body)
 end
 
+local function parse_exception(data)
+  local exceptions_found = {}
+  local bedrock_match = data:gmatch("exception(%b{})")
+  for bedrock_data_match in bedrock_match do
+    local jsn = vim.json.decode(bedrock_data_match)
+    table.insert(exceptions_found, "- " .. jsn.message)
+  end
+  return exceptions_found
+end
+
 function M:parse_stream_data(ctx, data, opts)
   -- @NOTE: Decode and process Bedrock response
   -- Each response contains a Base64-encoded `bytes` field, which is decoded into JSON.
@@ -90,15 +100,23 @@ function M:parse_stream_data(ctx, data, opts)
     local json = vim.json.decode(data_stream)
     self:parse_response(ctx, data_stream, json.type, opts)
   end
+  local exceptions = parse_exception(data)
+  if #exceptions > 0 then
+    Utils.debug("Bedrock exceptions: ", vim.fn.json_encode(exceptions))
+    if opts.on_chunk then
+      opts.on_chunk("\n**Exception caught**\n\n")
+      opts.on_chunk(table.concat(exceptions, "\n"))
+    end
+    vim.schedule(function() opts.on_stop({ reason = "error" }) end)
+  end
 end
 
 function M:parse_response_without_stream(data, event_state, opts)
   if opts.on_chunk == nil then return end
-  local bedrock_match = data:gmatch("exception(%b{})")
-  opts.on_chunk("\n**Exception caught**\n\n")
-  for bedrock_data_match in bedrock_match do
-    local jsn = vim.json.decode(bedrock_data_match)
-    opts.on_chunk("- " .. jsn.message .. "\n")
+  local exceptions = parse_exception(data)
+  if #exceptions > 0 then
+    opts.on_chunk("\n**Exception caught**\n\n")
+    opts.on_chunk(table.concat(exceptions, "\n"))
   end
   vim.schedule(function() opts.on_stop({ reason = "complete" }) end)
 end

lua/avante/utils/test.lua

@@ -0,0 +1,15 @@
+-- This is a helper for unit tests.
+local M = {}
+
+function M.read_file(fn)
+  fn = vim.uv.cwd() .. "/" .. fn
+  local file = io.open(fn, "r")
+  if file then
+    local data = file:read("*all")
+    file:close()
+    return data
+  end
+  return fn
+end
+
+return M