Ensure op_can_download() returns FALSE for hand rolled sql (#552)

Fixes #540

NEWS.md

@@ -1,5 +1,8 @@
 # bigrquery (development version)
 
+* `con |> tbl(sql("..."))` now works robustly once more (#540). (No more
+  "URL using bad/illegal format or missing URL" error).
+
 * Align Google APIs URLs to Google Cloud Discovery docs. This enables support for Private and Restricted Google APIs configurations.
   (@husseyd, #541)
   - `R/bq-request.R`

R/dplyr.R

@@ -153,6 +153,7 @@ op_can_download.lazy_base_query <- function(x) dbplyr::is.ident(x$x)
 
 query_is_head_only <- function(x) {
   if (!inherits(x$x, "lazy_base_remote_query")) return(FALSE)
+  if (inherits(x$x$x, "sql")) return(FALSE)
 
   vars_base <- dbplyr::op_vars(x$x)
   if (!is_select_trivial(x$select, vars_base)) return(FALSE)

tests/testthat/test-dplyr.R

@@ -99,6 +99,10 @@ test_that("collect can identify directly download tables", {
 
   x <- dplyr::collect(bq1)
   expect_s3_class(x, "tbl")
+
+  bq5 <- dplyr::tbl(con, dplyr::sql("SELECT * FROM mtcars"))
+  expect_false(op_can_download(bq5))
+  expect_false(op_can_download(head(bq5)))
 })
 
 test_that("casting uses bigquery types", {