message: Refine dummy-ls test to pick up on the exiting due to shutdown.
  This makes sure the exit doesn't happen due to a file
  issue but indeed due to the reception of the shutdown notification.
diff: DUMMY_LSP="$(rlocation ${TEST_WORKSPACE}/$1)"
  TMP_IN=${TEST_TMPDIR:-/tmp/}/test-lsp-in.txt
  -TMP_OUT=${TEST_TMPDIR:-/tmp/}/test-lsp-out.txt
  +JSON_OUT=${TEST_TMPDIR:-/tmp/}/test-lsp-out-json.txt
  +MSG_OUT=${TEST_TMPDIR:-/tmp/}/test-lsp-out-msg.txt
  # One message per line, converted by the awk script to header/body.
  # Simple end-to-end test
  @@ -29,11 +30,23 @@ awk '{printf("Content-Length: %d\r\n\r\n%s", length($0), $0)}' > ${TMP_IN} <<EOF
  {"jsonrpc":"2.0","method":"shutdown","params":{},"id":2}
  EOF
  -"${DUMMY_LSP}" < ${TMP_IN} > "${TMP_OUT}"
  +"${DUMMY_LSP}" < ${TMP_IN} > "${JSON_OUT}" 2> "${MSG_OUT}"
  -cat ${TMP_OUT}
  +echo "-- JSON protocol output --"
  +cat ${JSON_OUT}
  +
  +echo "-- stderr messages --"
  +cat ${MSG_OUT}
  # Check if an expected content is returned
  -grep "testing language server" "${TMP_OUT}" > /dev/null
  +grep "testing language server" "${JSON_OUT}" > /dev/null
  +if [ $? -ne 0 ]; then
  + echo "Didn't get initialize feedback message"
  + exit 1
  +fi
  -exit $?
  +grep "shutdown request" "${MSG_OUT}" > /dev/null
  +if [ $? -ne 0 ]; then
  + echo "Didn't get shutdown feedback"
  + exit 1
  +fi
  