Quote table names starting by number

lib/carto/table_utils.rb

@@ -19,10 +19,10 @@ module Carto
     private
 
     ALREADY_QUOTED = /\A".*"\Z/
-    NON_VALID_CHARACTERS = /[^[a-z][A-Z][0-9]_$]/
+    VALID_IDENTIFIER = /^[a-zA-Z_][a-zA-Z0-9_$]*$/
 
     def dashes_quoting(name)
-      name && !name.match(ALREADY_QUOTED) && name =~ NON_VALID_CHARACTERS ? "\"#{name}\"" : name
+      name && !name.match(ALREADY_QUOTED) && !name.match(VALID_IDENTIFIER) ? "\"#{name}\"" : name
     end
 
     def can_be_quoted?(name)

spec/lib/carto/table_utils_spec.rb

@@ -49,6 +49,11 @@ describe Carto::TableUtils do
       table_utils.safe_schema_and_table_quoting('public', 'my""ta-ble').should eq 'public."my""ta-ble"'
     end
 
+    it 'quotes table names starting with numbers' do
+      table_utils.safe_schema_and_table_quoting('public', '42').should eq 'public."42"'
+      table_utils.safe_schema_and_table_quoting('public', 'a42').should eq 'public.a42'
+    end
+
     it 'does not quote already quoted strings' do
       table_utils.safe_schema_and_table_quoting('public', '"my-table"').should eq 'public."my-table"'
       table_utils.safe_schema_and_table_quoting('public', '"my""ta-ble"').should eq 'public."my""ta-ble"'