Bad column selections fail gracefully at interrogation

NEWS.md

@@ -15,6 +15,10 @@
 
   These dynamic values may be useful for validations that get expanded into multiple steps.
 
+## Minor improvements and bug fixes
+
+* When no columns are returned from a `{tidyselect}` expression in `columns`, the agent's report now displays the originally supplied *expression* instead of simply blank (e.g., in `create_agent(small_table) %>% col_vals_null(matches("z"))`).
+
 # pointblank 0.11.4
 
 * Fixes issue with gt `0.9.0` compatibility.

R/col_exists.R

@@ -227,7 +227,7 @@ NULL
 #' @export
 col_exists <- function(
     x,
-    columns,
+    columns = NULL,
     actions = NULL,
     step_id = NULL,
     label = NULL,
@@ -242,13 +242,6 @@ col_exists <- function(
   columns <- rlang::enquo(columns)
   # Get `columns` as a label
   columns_expr <- as_columns_expr(columns)
-  # Require columns to be specified
-  if (rlang::quo_is_missing(columns)) {
-    stop('argument "columns" is missing, with no default')
-  }
-  if (rlang::quo_is_null(columns)) {
-    columns <- rlang::quo(tidyselect::everything())
-  }
 
   # Resolve the columns based on the expression
   ## Only for `col_exists()`: error gracefully if column not found
@@ -257,15 +250,14 @@ col_exists <- function(
                            allow_empty = FALSE),
     error = function(cnd) cnd$i %||% cnd
   )
+  ## Missing column selection
   if (rlang::is_error(columns)) {
     cnd <- columns
-    # tidyselect 0-column selection should contextualize attempted column
-    if (is.null(cnd$parent)) {
-      columns <- columns_expr
-    } else {
-      # Evaluation errors should be chained and rethrown
-      rlang::abort("Evaluation error in `columns`", parent = cnd$parent)
+    if (inherits(cnd, "resolve_eval_err")) {
+      # Evaluation errors should be rethrown
+      rlang::cnd_signal(cnd)
     }
+    columns <- NA_character_
   }
 
   if (is_a_table_object(x)) {

R/get_agent_report.R

@@ -751,16 +751,40 @@ get_agent_report <- function(
           }
         }
 
-        if (
-          is.null(column_i) |
-          (is.list(column_i) && is.na(unlist(column_i)))
-        ) {
-
-          NA_character_
-
-        } else if (is.na(column_i)) {
-
-          NA_character_
+        # If column missing
+        if (is.null(column_i) || identical(unlist(column_i), NA_character_)) {
+
+          columns_expr <- validation_set$columns_expr[[x]]
+          not_interrogated <- is.na(validation_set$eval_error[[x]])
+          eval_error <- isTRUE(validation_set$eval_error[[x]])
+
+          # If column selection attempted AND:
+          # - in validation planning, OR
+          # - the evaluation errors, OR
+          # - is a col_exists() step
+          show_column_expr <- columns_expr != "NULL" &&
+            (not_interrogated || eval_error || assertion_str == "col_exists")
+          # Then display the original column selection expression for debugging
+          if (show_column_expr) {
+            as.character(
+              htmltools::tags$p(
+                title = columns_expr,
+                style = htmltools::css(
+                  `margin-top` = "0",
+                  `margin-bottom` = "0",
+                  `font-family` = "monospace",
+                  `white-space` = "nowrap",
+                  `text-overflow` = "ellipsis",
+                  overflow = "hidden",
+                  color = if (eval_error) "firebrick",
+                  `font-face` = "maroon"
+                ),
+                columns_expr
+              )
+            )
+          } else {
+            NA_character_
+          }
 
         } else {
 

R/interrogate.R

@@ -251,15 +251,6 @@ interrogate <- function(
       agent$validation_set[[i, "eval_active"]] <- FALSE
     }
 
-    # Set the validation step as `active = FALSE` if there is a
-    # no column available as a result of a select expression
-    if (!is.null(agent$validation_set$column[[i]]) &&
-        is.na(agent$validation_set$column[[i]]) &&
-        agent$validation_set$assertion_type[[i]] %in%
-        column_expansion_fns_vec()) {
-      agent$validation_set[[i, "eval_active"]] <- FALSE
-    }
-
     # Skip the validation step if `active = FALSE`
     if (!agent$validation_set[[i, "eval_active"]]) {
 
@@ -1070,7 +1061,7 @@ interrogate_comparison <- function(
   # Obtain the target column as a label
   column <- 
     get_column_as_sym_at_idx(agent = agent, idx = idx) %>%
-    rlang::as_label()
+    as.character()
 
   # Determine whether NAs should be allowed
   na_pass <- get_column_na_pass_at_idx(agent = agent, idx = idx)
@@ -2226,13 +2217,21 @@ interrogate_col_exists <- function(
   # Obtain the target column as a symbol
   column <- get_column_as_sym_at_idx(agent = agent, idx = idx)
 
+  # Get `column_expr` to signal error if user didn't supply `columns`
+  column_input_missing <- agent$validation_set$columns_expr[idx] == "NULL"
+
   # Create function for validating the `col_exists()` step function
   tbl_col_exists <- function(
     table,
     column,
-    column_names
+    column_names,
+    column_input_missing
   ) {
 
+    if (column_input_missing) {
+      stop("`columns` argument must be supplied.", call. = FALSE)
+    }
+
     # Ensure that the input `table` is actually a table object
     tbl_validity_check(table = table)
 
@@ -2244,7 +2243,8 @@ interrogate_col_exists <- function(
     tbl_col_exists(
       table = table,
       column = {{ column }},
-      column_names = column_names
+      column_names = column_names,
+      column_input_missing = column_input_missing
     )
   )
 }
@@ -2313,31 +2313,22 @@ interrogate_distinct <- function(
     table
 ) {
 
-  # Determine if grouping columns are provided in the test
-  # for distinct rows and parse the column names
-  if (!is.na(agent$validation_set$column[idx] %>% unlist())) {
-
+  column_names <- 
+    get_column_as_sym_at_idx(agent = agent, idx = idx) %>%
+    as.character()
+
+  if (grepl("(,|&)", column_names)) {
     column_names <- 
-      get_column_as_sym_at_idx(agent = agent, idx = idx) %>%
-      as.character()
-
-    if (grepl("(,|&)", column_names)) {
-      column_names <- 
-        strsplit(split = "(, |,|&)", column_names) %>%
-        unlist()
-    }
-
-    if (length(column_names) == 1 && column_names == "NA") {
-      if (uses_tidyselect(expr_text = agent$validation_set$columns_expr[idx])) {
-        column_names <- character(0)
-      }
-    }
-
-  } else if (is.na(agent$validation_set$column[idx] %>% unlist())) {
-    column_names <- get_all_cols(agent = agent)
+      strsplit(split = "(, |,|&)", column_names) %>%
+      unlist()
   }
 
-  col_syms <- rlang::syms(column_names)
+  if (identical(column_names, NA_character_)) {
+    # If column is missing, let it get caught by `column_validity_has_columns`
+    col_syms <- NULL
+  } else {
+    col_syms <- rlang::syms(column_names)
+  }
 
   # Create function for validating the `rows_distinct()` step function
   tbl_rows_distinct <- function(
@@ -2413,31 +2404,22 @@ interrogate_complete <- function(
     table
 ) {
 
-  # Determine if grouping columns are provided in the test
-  # for distinct rows and parse the column names
-  if (!is.na(agent$validation_set$column[idx] %>% unlist())) {
-
+  column_names <- 
+    get_column_as_sym_at_idx(agent = agent, idx = idx) %>%
+    as.character()
+
+  if (grepl("(,|&)", column_names)) {
     column_names <- 
-      get_column_as_sym_at_idx(agent = agent, idx = idx) %>%
-      as.character()
-
-    if (grepl("(,|&)", column_names)) {
-      column_names <- 
-        strsplit(split = "(, |,|&)", column_names) %>%
-        unlist()
-    }
-
-    if (length(column_names) == 1 && column_names == "NA") {
-      if (uses_tidyselect(expr_text = agent$validation_set$columns_expr[idx])) {
-        column_names <- character(0)
-      }
-    }
-
-  } else if (is.na(agent$validation_set$column[idx] %>% unlist())) {
-    column_names <- get_all_cols(agent = agent)
+      strsplit(split = "(, |,|&)", column_names) %>%
+      unlist()
   }
 
-  col_syms <- rlang::syms(column_names)
+  if (identical(column_names, NA_character_)) {
+    # If column is missing, let it get caught by `column_validity_has_columns`
+    col_syms <- NULL
+  } else {
+    col_syms <- rlang::syms(column_names)
+  }
 
   # Create function for validating the `rows_complete()` step function
   tbl_rows_complete <- function(
@@ -2823,15 +2805,9 @@ column_validity_checks_column_value <- function(
     value
 ) {
 
-  table_colnames <- colnames(table)
+  column_validity_checks_column(table, column)
 
-  if (!(as.character(column) %in% table_colnames)) {
-
-    stop(
-      "The value for `column` doesn't correspond to a column name.",
-      call. = FALSE
-    )
-  }
+  table_colnames <- colnames(table)
 
   if (inherits(value, "name")) {
 
@@ -2851,7 +2827,7 @@ column_validity_checks_column_value <- function(
 # Validity check for presence of columns
 column_validity_has_columns <- function(columns) {
 
-  if (length(columns) < 1) {
+  if (length(columns) < 1 || identical(columns, NA_character_)) {
     stop(
       "The column selection statement that was used yielded no columns.",
       call. = FALSE
@@ -2865,6 +2841,8 @@ column_validity_checks_column <- function(
     column
 ) {
 
+  column_validity_has_columns(as.character(column))
+
   table_colnames <- colnames(table)
 
   if (!(as.character(column) %in% table_colnames)) {
@@ -2884,15 +2862,9 @@ column_validity_checks_ib_nb <- function(
     right
 ) {
 
-  table_colnames <- colnames(table)
+  column_validity_checks_column(table, column)
 
-  if (!(as.character(column) %in% table_colnames)) {
-
-    stop(
-      "The value for `column` doesn't correspond to a column name.",
-      call. = FALSE
-    )
-  }
+  table_colnames <- colnames(table)
 
   if (inherits(left, "name")) {
 

R/rows_complete.R

@@ -296,7 +296,7 @@ rows_complete <- function(
   # Capture the `columns` expression
   columns <- rlang::enquo(columns)
   # `rows_*()` functions treat `NULL` as `everything()`
-  if (rlang::quo_is_null(columns)) {
+  if (rlang::quo_is_null(columns) || rlang::quo_is_missing(columns)) {
     columns <- rlang::quo(tidyselect::everything())
   }
   # Get `columns` as a label
@@ -333,12 +333,8 @@ rows_complete <- function(
 
   agent <- x
 
-  if (length(columns) > 0) {
+  if (length(columns) > 1) {
     columns <- paste(columns, collapse = ", ")
-  } else if (length(columns) == 1) {
-    columns <- columns
-  } else {
-    columns <- NULL
   }
 
   if (is.null(brief)) {

R/rows_distinct.R

@@ -297,7 +297,7 @@ rows_distinct <- function(
   # Capture the `columns` expression
   columns <- rlang::enquo(columns)
   # `rows_*()` functions treat `NULL` as `everything()`
-  if (rlang::quo_is_null(columns)) {
+  if (rlang::quo_is_null(columns) || rlang::quo_is_missing(columns)) {
     columns <- rlang::quo(tidyselect::everything())
   }
   # Get `columns` as a label
@@ -334,12 +334,8 @@ rows_distinct <- function(
 
   agent <- x
 
-  if (length(columns) > 0) {
+  if (length(columns) > 1) {
     columns <- paste(columns, collapse = ", ")
-  } else if (length(columns) == 1) {
-    columns <- columns
-  } else {
-    columns <- NULL
   }
 
   if (is.null(brief)) {