From c5aed9c1d51b4504a9614a96fdb1651a1a58fa2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kirill=20M=C3=BCller?= <kirill@cynkra.com>
Date: Sat, 16 Dec 2023 13:32:21 +0100
Subject: [PATCH] feat: Require support for `dbFetch(n = NA)`

---
 R/spec-result-fetch.R    | 17 +++++++++++++++--
 man/spec_result_fetch.Rd |  3 +++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/R/spec-result-fetch.R b/R/spec-result-fetch.R
index 8699f7bbe..3cbcc1bbf 100644
--- a/R/spec-result-fetch.R
+++ b/R/spec-result-fetch.R
@@ -39,6 +39,19 @@ spec_result_fetch <- list(
     expect_identical(class(rows), "data.frame")
   },
 
+  fetch_na_rows = function(ctx, con) {
+    if (as.package_version(ctx$tweaks$dbitest_version) < "1.7.4") {
+      skip(paste0("tweak: dbitest_version: ", ctx$tweaks$dbitest_version))
+    }
+
+    #' Passing `n = NA` is supported and returns an arbitrary number of rows (at least one)
+    #' as specified by the driver, but at most the remaining rows in the result set.
+    query <- trivial_query()
+    res <- local_result(dbSendQuery(con, query))
+    rows <- check_df(dbFetch(res, n = NA))
+    expect_equal(rows, data.frame(a = 1.5))
+  },
+
   #'
   fetch_closed = function(con) {
     #' @section Failure modes:
@@ -60,19 +73,19 @@ spec_result_fetch <- list(
     expect_error(dbFetch(res, 1.5))
     expect_error(dbFetch(res, integer()))
     expect_error(dbFetch(res, 1:3))
-    expect_error(dbFetch(res, NA_integer_))
   },
 
   fetch_n_good_after_bad = function(con) {
     #' but a subsequent call to `dbFetch()` with proper `n` argument succeeds.
     query <- trivial_query()
     res <- local_result(dbSendQuery(con, query))
-    expect_error(dbFetch(res, NA_integer_))
+    expect_error(dbFetch(res, -2))
     rows <- check_df(dbFetch(res))
     expect_equal(rows, data.frame(a = 1.5))
   },
 
   fetch_no_return_value = function(con, table_name) {
+    #'
     #' Calling `dbFetch()` on a result set from a data manipulation query
     #' created by [dbSendStatement()]
     #' can be fetched and return an empty data frame, with a warning.
diff --git a/man/spec_result_fetch.Rd b/man/spec_result_fetch.Rd
index 8459f90f5..96ffd66a3 100644
--- a/man/spec_result_fetch.Rd
+++ b/man/spec_result_fetch.Rd
@@ -11,6 +11,8 @@ columns as fields in the result set,
 even if the result is a single value
 or has one
 or zero rows.
+Passing \code{n = NA} is supported and returns an arbitrary number of rows (at least one)
+as specified by the driver, but at most the remaining rows in the result set.
 }
 \description{
 spec_result_fetch
@@ -21,6 +23,7 @@ An attempt to fetch from a closed result set raises an error.
 If the \code{n} argument is not an atomic whole number
 greater or equal to -1 or Inf, an error is raised,
 but a subsequent call to \code{dbFetch()} with proper \code{n} argument succeeds.
+
 Calling \code{dbFetch()} on a result set from a data manipulation query
 created by \code{\link[=dbSendStatement]{dbSendStatement()}}
 can be fetched and return an empty data frame, with a warning.