Disable skipping if only one snapshot left

Fixes #2025

Author: hadley

NEWS.md

@@ -1,5 +1,6 @@
 # testthat (development version)
 
+* `snapshot_review()` disables the skip button if there's only one snapshot to review (#2025).
 * Interrupting a test now prints the test name. This makes it easier to tell where a very slow test might be hanging (#1464)
 * Parallel testthat now does not ignore test files with syntax errors (#1360).
 * `expect_lt()`, `expect_gt()`, and friends have a refined display that is more likely to display the correct number of digits and shows you the actual values compared.

R/snapshot-manage.R

@@ -77,6 +77,9 @@ review_app <- function(name, old_path, new_path) {
       diffviewer::visual_diff(old_path[[i()]], new_path[[i()]])
     })
 
+    # Can't skip if there's only one file to review
+    shiny::updateActionButton(session, "skip", disabled = (n <= 1))
+
     # Handle buttons - after clicking update move input$cases to next case,
     # and remove current case (for accept/reject). If no cases left, close app
     shiny::observeEvent(input$reject, {
@@ -104,6 +107,10 @@ review_app <- function(name, old_path, new_path) {
         choices = case_index[!handled],
         selected = i
       )
+
+      n_left <- sum(!handled)
+      # Disable skip button if only one case remains
+      shiny::updateActionButton(session, "skip", disabled = (n_left <= 1))
     }
     next_case <- function() {
       if (all(handled)) {