do not allow grouping by crucial variables

R/aggregate_alignment_loanbook_exposure.R

@@ -240,5 +240,29 @@ validate_input_data_aggregate_alignment_loanbook_exposure <- function(data,
     )
   )
 
+  if (!is.null(.by)) {
+    if (
+      any(
+        .by %in% c(
+          group_vars,
+          "name_abcd",
+          "activity_unit",
+          "scenario_source",
+          "alignment_metric",
+          "id_loan",
+          "loan_size_outstanding",
+          "loan_size_outstanding_currency",
+          "name_abcd",
+          "sector"
+        )
+      )
+    ) {
+      stop(
+        "It is not possible to group by the critical columns of the `data` and
+        `matched` inputs. Please check your .by argument!"
+      )
+    }
+  }
+
   invisible()
 }

tests/testthat/test-aggregate_alignment_loanbook_exposure.R

@@ -131,7 +131,7 @@ test_matched_dot_by <- tibble::tribble(
 )
 # styler: on
 
-test_that("net aggregate results with grouped with bad .by returns ", {
+test_that("net aggregate results with bad .by returns error", {
   expect_error(
     {
       test_data_company_net %>%
@@ -145,6 +145,21 @@ test_that("net aggregate results with grouped with bad .by returns ", {
   )
 })
 
+test_that("net aggregate results with .by arg as crucial variable returns error", {
+  expect_error(
+    {
+      test_data_company_net %>%
+        aggregate_alignment_loanbook_exposure(
+          matched = test_matched_dot_by,
+          level = test_level_net,
+          .by = "loan_size_outstanding"
+        )
+    },
+    regexp = "It is not possible to group by the critical columns of the `data` and
+        `matched` inputs."
+  )
+})
+
 test_that("net aggregate results with .by specified returns results for each group", {
   n_groups <- length(unique(test_matched_dot_by$foo))