lib/lhm/migrator.rb in lhm-2.1.0 vs lib/lhm/migrator.rb in lhm-2.2.0

@@ -11,17 +11,18 @@
   # `run` returns a Migration which can be used for the remaining process.
   class Migrator
     include Command
     include SqlHelper
 
-    attr_reader :name, :statements, :connection, :conditions
+    attr_reader :name, :statements, :connection, :conditions, :renames
 
     def initialize(table, connection = nil)
       @connection = connection
       @origin = table
       @name = table.destination_name
       @statements = []
+      @renames = {}
     end
 
     # Alter a table with a custom statement
     #
     # @example
@@ -50,11 +51,11 @@
     #   end
     #
     # @param [String] name Name of the column to add
     # @param [String] definition Valid SQL column definition
     def add_column(name, definition)
-      ddl("alter table `%s` add column `%s` %s" % [@name, name, definition])
+      ddl('alter table `%s` add column `%s` %s' % [@name, name, definition])
     end
 
     # Change an existing column to a new definition
     #
     # @example
@@ -64,24 +65,45 @@
     #   end
     #
     # @param [String] name Name of the column to change
     # @param [String] definition Valid SQL column definition
     def change_column(name, definition)
-      ddl("alter table `%s` modify column `%s` %s" % [@name, name, definition])
+      ddl('alter table `%s` modify column `%s` %s' % [@name, name, definition])
     end
 
+    # Rename an existing column.
+    #
+    # @example
+    #
+    #   Lhm.change_table(:users) do |m|
+    #     m.rename_column(:login, :username)
+    #   end
+    #
+    # @param [String] old Name of the column to change
+    # @param [String] nu New name to use for the column
+    def rename_column(old, nu)
+      col = @origin.columns[old.to_s]
+
+      definition = col[:type]
+      definition += ' NOT NULL' unless col[:is_nullable]
+      definition += " DEFAULT #{@connection.quote_value(col[:column_default])}" if col[:column_default]
+
+      ddl('alter table `%s` change column `%s` `%s` %s' % [@name, old, nu, definition])
+      @renames[old.to_s] = nu.to_s
+    end
+
     # Remove a column from a table
     #
     # @example
     #
     #   Lhm.change_table(:users) do |m|
     #     m.remove_column(:comment)
     #   end
     #
     # @param [String] name Name of the column to delete
     def remove_column(name)
-      ddl("alter table `%s` drop `%s`" % [@name, name])
+      ddl('alter table `%s` drop `%s`' % [@name, name])
     end
 
     # Add an index to a table
     #
     # @example
@@ -134,14 +156,14 @@
     #   for compound indexes.
     # @param [String, Symbol] index_name
     #   Optional name of the index to be removed
     def remove_index(columns, index_name = nil)
       columns = [columns].flatten.map(&:to_sym)
-      from_origin = @origin.indices.find {|name, cols| cols.map(&:to_sym) == columns}
+      from_origin = @origin.indices.find { |name, cols| cols.map(&:to_sym) == columns }
       index_name ||= from_origin[0] unless from_origin.nil?
       index_name ||= idx_name(@origin.name, columns)
-      ddl("drop index `%s` on `%s`" % [index_name, @name])
+      ddl('drop index `%s` on `%s`' % [index_name, @name])
     end
 
     # Filter the data that is copied into the new table by the provided SQL.
     # This SQL will be inserted into the copy directly after the "from"
     # statement - so be sure to use inner/outer join syntax and not cross joins.
@@ -164,11 +186,11 @@
       unless @connection.table_exists?(@origin.name)
         error("could not find origin table #{ @origin.name }")
       end
 
       unless @origin.satisfies_primary_key?
-        error("origin does not satisfy primary key requirements")
+        error('origin does not satisfy primary key requirements')
       end
 
       dest = @origin.destination_name
 
       if @connection.table_exists?(dest)
@@ -177,11 +199,11 @@
     end
 
     def execute
       destination_create
       @connection.sql(@statements)
-      Migration.new(@origin, destination_read, conditions)
+      Migration.new(@origin, destination_read, conditions, renames)
     end
 
     def destination_create
       @connection.destination_create(@origin)
     end
@@ -189,12 +211,19 @@
     def destination_read
       Table.parse(@origin.destination_name, connection)
     end
 
     def index_ddl(cols, unique = nil, index_name = nil)
-      type = unique ? "unique index" : "index"
+      assert_valid_idx_name(index_name)
+      type = unique ? 'unique index' : 'index'
       index_name ||= idx_name(@origin.name, cols)
       parts = [type, index_name, @name, idx_spec(cols)]
-      "create %s `%s` on `%s` (%s)" % parts
+      'create %s `%s` on `%s` (%s)' % parts
+    end
+
+    def assert_valid_idx_name(index_name)
+      if index_name && !(index_name.is_a?(String) || index_name.is_a?(Symbol))
+        raise ArgumentError, 'index_name must be a string or symbol'
+      end
     end
   end
 end