audit calls to expect_error() for backend-*.R files (#1553)

* audit `expect_error()` for `backend-.R`
* audit `expect_error()` for `backend-access.R`
* audit `expect_error()` for `backend-mssql.R`
* audit `expect_error()` for `backend-oracle.R`
* audit `expect_error()` for `backend-postgres.R`
* audit `expect_error()` for `backend-redshift.R`
* audit `expect_error()` for `backend-spark-sql.R`

also, subclass widely-used error.

R/translate-sql-helpers.R

@@ -273,7 +273,10 @@ sql_not_supported <- function(f) {
   check_string(f)
 
   function(...) {
-    cli_abort("{.fun {f}} is not available in this SQL variant.")
+    cli_abort(
+      "{.fun {f}} is not available in this SQL variant.",
+      class = "dbplyr_error_unsupported_fn"
+    )
   }
 }
 

tests/testthat/_snaps/backend-.md

@@ -1,3 +1,11 @@
+# basic arithmetic is correct
+
+    Code
+      test_translate_sql(100L %/% 3L)
+    Condition
+      Error in `100L %/% 3L`:
+      ! `%/%()` is not available in this SQL variant.
+
 # can translate subsetting
 
     Code

tests/testthat/_snaps/backend-access.md

@@ -1,3 +1,12 @@
+# custom scalar translated correctly
+
+    Code
+      test_translate_sql(paste(x, collapse = "-"))
+    Condition
+      Error in `check_collapse()`:
+      ! `collapse` not supported in DB translation of `paste()`.
+      i Please use `str_flatten()` instead.
+
 # queries translate correctly
 
     Code

tests/testthat/_snaps/backend-mssql.md

@@ -32,6 +32,47 @@
       ! `abbr = TRUE` isn't supported in SQL Server translation.
       i It must be FALSE instead.
 
+---
+
+    Code
+      test_translate_sql(quarter(x, fiscal_start = 5))
+    Condition
+      Error in `quarter()`:
+      ! `fiscal_start = 5` isn't supported in SQL Server translation.
+      i It must be 1 instead.
+
+# custom clock functions translated correctly
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "year"))
+    Condition
+      Error in `date_count_between()`:
+      ! `precision` must be "day" on SQL backends.
+
+---
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "day", n = 5))
+    Condition
+      Error in `date_count_between()`:
+      ! `n` must be "1" on SQL backends.
+
+# difftime is translated correctly
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, units = "auto"))
+    Condition
+      Error in `difftime()`:
+      ! The only supported value for `units` on SQL backends is "days"
+
+---
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, tz = "UTC", units = "days"))
+    Condition
+      Error in `difftime()`:
+      ! The `tz` argument is not supported for SQL backends.
+
 # convert between bit and boolean as needed
 
     Code

tests/testthat/_snaps/backend-oracle.md

@@ -137,3 +137,19 @@
         SELECT 1, '{1,2,3}' FROM DUAL
       ) `values_table`
 
+# difftime is translated correctly
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, units = "auto"))
+    Condition
+      Error in `difftime()`:
+      ! The only supported value for `units` on SQL backends is "days"
+
+---
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, tz = "UTC", units = "days"))
+    Condition
+      Error in `difftime()`:
+      ! The `tz` argument is not supported for SQL backends.
+

tests/testthat/_snaps/backend-postgres.md

@@ -1,18 +1,68 @@
+# pasting translated correctly
+
+    Code
+      test_translate_sql(paste0(x, collapse = ""), window = FALSE)
+    Condition
+      Error in `check_collapse()`:
+      ! `collapse` not supported in DB translation of `paste()`.
+      i Please use `str_flatten()` instead.
+
+# custom lubridate functions translated correctly
+
+    Code
+      test_translate_sql(quarter(x, fiscal_start = 2))
+    Condition
+      Error in `quarter()`:
+      ! `fiscal_start = 2` isn't supported in PostgreSQL translation.
+      i It must be 1 instead.
+
+# custom clock functions translated correctly
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "year"))
+    Condition
+      Error in `date_count_between()`:
+      ! `precision` must be "day" on SQL backends.
+
+---
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "day", n = 5))
+    Condition
+      Error in `date_count_between()`:
+      ! `n` must be "1" on SQL backends.
+
+# difftime is translated correctly
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, units = "auto"))
+    Condition
+      Error in `difftime()`:
+      ! The only supported value for `units` on SQL backends is "days"
+
+---
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, tz = "UTC", units = "days"))
+    Condition
+      Error in `difftime()`:
+      ! The `tz` argument is not supported for SQL backends.
+
 # custom window functions translated correctly
 
     Code
-      (expect_error(test_translate_sql(quantile(x, 0.3, na.rm = TRUE), window = TRUE))
-      )
-    Output
-      <error/rlang_error>
+      test_translate_sql(quantile(x, 0.3, na.rm = TRUE), window = TRUE)
+    Condition
       Error in `quantile()`:
       ! Translation of `quantile()` in `mutate()` is not supported for PostgreSQL.
       i Use a combination of `summarise()` and `left_join()` instead:
         `df %>% left_join(summarise(<col> = quantile(x, 0.3, na.rm = TRUE)))`.
+
+---
+
     Code
-      (expect_error(test_translate_sql(median(x, na.rm = TRUE), window = TRUE)))
-    Output
-      <error/rlang_error>
+      test_translate_sql(median(x, na.rm = TRUE), window = TRUE)
+    Condition
       Error in `median()`:
       ! Translation of `median()` in `mutate()` is not supported for PostgreSQL.
       i Use a combination of `summarise()` and `left_join()` instead:

tests/testthat/_snaps/backend-redshift.md

@@ -35,3 +35,35 @@
         SELECT 1, '{1,2,3}'
       ) AS `values_table`
 
+# custom clock functions translated correctly
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "year"))
+    Condition
+      Error in `date_count_between()`:
+      ! `precision` must be "day" on SQL backends.
+
+---
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "day", n = 5))
+    Condition
+      Error in `date_count_between()`:
+      ! `n` must be "1" on SQL backends.
+
+# difftime is translated correctly
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, units = "auto"))
+    Condition
+      Error in `difftime()`:
+      ! The only supported value for `units` on SQL backends is "days"
+
+---
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, tz = "UTC", units = "days"))
+    Condition
+      Error in `difftime()`:
+      ! The `tz` argument is not supported for SQL backends.
+

tests/testthat/_snaps/backend-spark-sql.md

@@ -0,0 +1,32 @@
+# custom clock functions translated correctly
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "year"))
+    Condition
+      Error in `date_count_between()`:
+      ! `precision` must be "day" on SQL backends.
+
+---
+
+    Code
+      test_translate_sql(date_count_between(date_column_1, date_column_2, "day", n = 5))
+    Condition
+      Error in `date_count_between()`:
+      ! `n` must be "1" on SQL backends.
+
+# difftime is translated correctly
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, units = "auto"))
+    Condition
+      Error in `difftime()`:
+      ! The only supported value for `units` on SQL backends is "days"
+
+---
+
+    Code
+      test_translate_sql(difftime(start_date, end_date, tz = "UTC", units = "days"))
+    Condition
+      Error in `difftime()`:
+      ! The `tz` argument is not supported for SQL backends.
+

tests/testthat/_snaps/backend-sqlite.md

@@ -1,20 +1,3 @@
-# custom aggregates translated
-
-    Code
-      (expect_error(test_translate_sql(quantile(x, 0.5, na.rm = TRUE), window = FALSE))
-      )
-    Output
-      <error/rlang_error>
-      Error in `quantile()`:
-      ! `quantile()` is not available in this SQL variant.
-    Code
-      (expect_error(test_translate_sql(quantile(x, 0.5, na.rm = TRUE), window = TRUE))
-      )
-    Output
-      <error/rlang_error>
-      Error in `quantile()`:
-      ! `quantile()` is not available in this SQL variant.
-
 # custom SQL translation
 
     Code

tests/testthat/_snaps/translate-sql-helpers.md

@@ -1,3 +1,11 @@
+# warns informatively with unsupported function
+
+    Code
+      sql_not_supported("cor")()
+    Condition
+      Error:
+      ! `cor()` is not available in this SQL variant.
+
 # duplicates throw an error
 
     Code

tests/testthat/test-backend-.R

@@ -15,7 +15,7 @@ test_that("basic arithmetic is correct", {
   expect_equal(test_translate_sql(5 ^ 2), sql("POWER(5.0, 2.0)"))
   expect_equal(test_translate_sql(100L %% 3L), sql("100 % 3"))
 
-  expect_error(test_translate_sql(100L %/% 3L), "not available")
+  expect_snapshot(error = TRUE, test_translate_sql(100L %/% 3L))
 })
 
 test_that("small numbers aren't converted to 0", {

tests/testthat/test-backend-access.R

@@ -34,7 +34,7 @@ test_that("custom scalar translated correctly", {
   # paste()
   expect_equal(test_translate_sql(paste(x, y, sep = "+")), sql("`x` & '+' & `y`"))
   expect_equal(test_translate_sql(paste0(x, y)), sql("`x` & `y`"))
-  expect_error(test_translate_sql(paste(x, collapse = "-")),"`collapse` not supported")
+  expect_snapshot(error = TRUE, test_translate_sql(paste(x, collapse = "-")))
   # Logic
   expect_equal(test_translate_sql(ifelse(x, "true", "false")), sql("IIF(`x`, 'true', 'false')"))
 })
@@ -45,9 +45,18 @@ test_that("custom aggregators translated correctly", {
   expect_equal(test_translate_sql(sd(x, na.rm = TRUE), window = FALSE),  sql("STDEV(`x`)"))
   expect_equal(test_translate_sql(var(x, na.rm = TRUE), window = FALSE), sql("VAR(`x`)"))
 
-  expect_error(test_translate_sql(cor(x), window = FALSE), "not available")
-  expect_error(test_translate_sql(cov(x), window = FALSE), "not available")
-  expect_error(test_translate_sql(n_distinct(x), window = FALSE), "not available")
+  expect_error(
+    test_translate_sql(cor(x), window = FALSE),
+    class = "dbplyr_error_unsupported_fn"
+  )
+  expect_error(
+    test_translate_sql(cov(x), window = FALSE),
+    class = "dbplyr_error_unsupported_fn"
+  )
+  expect_error(
+    test_translate_sql(n_distinct(x), window = FALSE),
+    class = "dbplyr_error_unsupported_fn"
+  )
 })
 
 test_that("custom escaping works as expected", {