correctly handle options that start with numbers (#3241)

correctly handle dynamic batch connect options that start with numbers.

apps/dashboard/app/javascript/dynamic_forms.js

@@ -709,6 +709,11 @@ function optionForFromToken(str) {
       }
 
       let optionForValue = mountainCaseWords(document.getElementById(optionForId).value);
+      // handle special case where the very first token here is a number.
+      // browsers expect a prefix of hyphens as if it's the next token.
+      if (optionForValue.match(/^\d/)) {
+        optionForValue = `-${optionForValue}`;
+      }
 
       hide = option.dataset[`optionFor${optionFor}${optionForValue}`] === 'false';
       if (hide) {

apps/dashboard/test/fixtures/sys_with_gateway_apps/bc_jupyter/form.yml

@@ -164,6 +164,8 @@ attributes:
           data-min-bc-num-hours-for-cluster-oakley: 111,
         ]
       - [ 'Economics 8846', 'astronomy-with/other-characters/8846.31.4' ]
+      - [ '123ABC', '123ABC' ]
+      - [ '456def', '456def' ]
   classroom_size:
     widget: select
     options:
@@ -179,6 +181,8 @@ attributes:
           data-option-for-classroom-astronomy-5678: false,
           data-option-for-classroom-astronomy-with/other-characters/8846.31.4: false,
           data-set-checkbox-test: 1,
+          data-option-for-classroom-123ABC: false,
+          data-option-for-classroom-456def: false,
         ]
   gpus:
     widget: number_field

apps/dashboard/test/system/batch_connect_test.rb

@@ -624,6 +624,27 @@ def make_bc_app(dir, form)
     find("##{bc_ele_id('bc_email_on_started')}", visible: false)
   end
 
+  test 'options that start with numbers hide other options' do
+    visit new_batch_connect_session_context_url('sys/bc_jupyter')
+
+    # defaults
+    assert_equal('physics_1234', find_value('classroom'))
+    assert_equal('small', find_value('classroom_size'))
+    assert_equal('', find_option_style('classroom_size', 'large'))
+
+    # now change the classroom and see large dissappear
+    select('123ABC', from: bc_ele_id('classroom'))
+    assert_equal('display: none;', find_option_style('classroom_size', 'large'))
+
+    # select the default, and it's back.
+    select('Physics 1234', from: bc_ele_id('classroom'))
+    assert_equal('', find_option_style('classroom_size', 'large'))
+
+    # now change the lowercase classroom and see large dissappear again.
+    select('456def', from: bc_ele_id('classroom'))
+    assert_equal('display: none;', find_option_style('classroom_size', 'large'))
+  end
+
   test 'options with numbers and slashes' do
     visit new_batch_connect_session_context_url('sys/bc_jupyter')