test: Sync tests with duckplyr (#596)

* test: Sync tests with duckplyr

* Skip

Author: krlmlr

tests/testthat/test-rel_api.R

@@ -8857,6 +8857,8 @@ test_that("relational mutate(c = 10, d = log10(c)) order-preserving", {
 })
 
 test_that("relational mutate(c = NA_character_, d = grepl('.', c)) order-preserving", {
+  skip_if_not(TEST_RE2)
+
   # Autogenerated
   drv <- duckdb()
   con <- dbConnect(drv)
@@ -9716,7 +9718,7 @@ test_that("relational mutate(d = if_else(a > 1, \"ok\", NA)) order-preserving",
   invisible(
     dbExecute(
       con,
-      'CREATE MACRO "if_else"(test, yes, no) AS (CASE WHEN test THEN yes ELSE no END)'
+      'CREATE MACRO "if_else"(test, yes, no) AS (CASE WHEN test IS NULL THEN NULL ELSE CASE WHEN test THEN yes ELSE no END END)'
     )
   )
   df1 <- data.frame(a = seq(1, 6, by = 1), b = rep(2, 6L), g = c(1L, 2L, 2L, 3L, 3L, 3L))
@@ -12868,6 +12870,8 @@ test_that("relational mutate(c = 10, d = log10(c)) order-enforcing", {
 })
 
 test_that("relational mutate(c = NA_character_, d = grepl('.', c)) order-enforcing", {
+  skip_if_not(TEST_RE2)
+
   # Autogenerated
   drv <- duckdb()
   con <- dbConnect(drv)
@@ -13733,7 +13737,7 @@ test_that("relational mutate(d = if_else(a > 1, \"ok\", NA)) order-enforcing", {
   invisible(
     dbExecute(
       con,
-      'CREATE MACRO "if_else"(test, yes, no) AS (CASE WHEN test THEN yes ELSE no END)'
+      'CREATE MACRO "if_else"(test, yes, no) AS (CASE WHEN test IS NULL THEN NULL ELSE CASE WHEN test THEN yes ELSE no END END)'
     )
   )
   df1 <- data.frame(a = seq(1, 6, by = 1), b = rep(2, 6L), g = c(1L, 2L, 2L, 3L, 3L, 3L))