Escape identifiers in more cases, if necessary

Based on work done in #136
pganalyze · Jul 1, 2019 · 100a0c5 · 100a0c5
1 parent 717380c
commit 100a0c5
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Showing 3 changed files with 787 additions and 16 deletions.
diff --git a/lib/pg_query/deparse.rb b/lib/pg_query/deparse.rb
@@ -1,5 +1,7 @@
-require_relative 'deparse/interval'
 require_relative 'deparse/alter_table'
+require_relative 'deparse/interval'
+require_relative 'deparse/keywords'
+
 class PgQuery
   # Reconstruct all of the parsed queries into their original form
   def deparse(tree = @tree)
@@ -194,7 +196,7 @@ def deparse_item(item, context = nil) # rubocop:disable Metrics/CyclomaticComple
         elsif [FUNC_CALL, TYPE_NAME, :operator, :defname_as].include?(context)
           node['str']
         else
-          format('"%s"', node['str'].gsub('"', '""'))
+          deparse_identifier(node['str'], escape_always: true)
         end
       when INTEGER
         node['ival'].to_s
@@ -211,6 +213,15 @@ def deparse_item_list(nodes, context = nil)
       nodes.map { |n| deparse_item(n, context) }
     end
 
+    def deparse_identifier(ident, escape_always: false)
+      return if ident.nil?
+      if escape_always || !ident[/^\w+$/] || KEYWORDS.include?(ident.upcase)
+        format('"%s"', ident.gsub('"', '""'))
+      else
+        ident
+      end
+    end
+
     def deparse_rangevar(node)
       output = []
       output << 'ONLY' unless node['inh']
@@ -283,7 +294,7 @@ def deparse_alias(node)
       if node['colnames']
         name + '(' + deparse_item_list(node['colnames']).join(', ') + ')'
       else
-        name
+        deparse_identifier(name)
       end
     end
 
@@ -334,7 +345,7 @@ def deparse_paramref(node)
 
     def deparse_restarget(node, context)
       if context == :select
-        [deparse_item(node['val']), node['name']].compact.join(' AS ')
+        [deparse_item(node['val']), deparse_identifier(node['name'])].compact.join(' AS ')
       elsif context == :update
         [node['name'], deparse_item(node['val'])].compact.join(' = ')
       elsif node['val'].nil?
@@ -446,7 +457,7 @@ def deparse_role_spec(node)
       return 'CURRENT_USER' if node['roletype'] == 1
       return 'SESSION_USER' if node['roletype'] == 2
       return 'PUBLIC' if node['roletype'] == 3
-      format('"%s"', node['rolename'].gsub('"', '""'))
+      deparse_identifier(node['rolename'], escape_always: true)
     end
 
     def deparse_aexpr_in(node)