Add option to specify custom index name

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 1.1.0 (not released yet)
+
+* Add option to specify custom index name
+
 # 1.0.3 (February 23, 2012)
 
 * Improve change_column

lib/lhm/migrator.rb

@@ -95,8 +95,10 @@ def remove_column(name)
     # @param [String, Symbol, Array<String, Symbol>] columns
     #   A column name given as String or Symbol. An Array of Strings or Symbols
     #   for compound indexes. It's possible to pass a length limit.
-    def add_index(columns)
-      ddl(index_ddl(columns))
+    # @param [String, Symbol] index_name
+    #   Optional name of the index to be created
+    def add_index(columns, index_name = nil)
+      ddl(index_ddl(columns, false, index_name))
     end
 
     # Add a unique index to a table
@@ -112,8 +114,10 @@ def add_index(columns)
     # @param [String, Symbol, Array<String, Symbol>] columns
     #   A column name given as String or Symbol. An Array of Strings or Symbols
     #   for compound indexes. It's possible to pass a length limit.
-    def add_unique_index(columns)
-      ddl(index_ddl(columns, :unique))
+    # @param [String, Symbol] index_name
+    #   Optional name of the index to be created
+    def add_unique_index(columns, index_name = nil)
+      ddl(index_ddl(columns, true, index_name))
     end
 
     # Remove an index from a table
@@ -128,8 +132,11 @@ def add_unique_index(columns)
     # @param [String, Symbol, Array<String, Symbol>] columns
     #   A column name given as String or Symbol. An Array of Strings or Symbols
     #   for compound indexes.
-    def remove_index(columns)
-      ddl("drop index `%s` on `%s`" % [idx_name(@origin.name, columns), @name])
+    # @param [String, Symbol] index_name
+    #   Optional name of the index to be removed
+    def remove_index(columns, index_name = nil)
+      index_name ||= idx_name(@origin.name, columns)
+      ddl("drop index `%s` on `%s`" % [index_name, @name])
     end
 
   private
@@ -167,9 +174,10 @@ def destination_read
       Table.parse(@origin.destination_name, connection)
     end
 
-    def index_ddl(cols, unique = nil)
+    def index_ddl(cols, unique = nil, index_name = nil)
       type = unique ? "unique index" : "index"
-      parts = [type, idx_name(@origin.name, cols), @name, idx_spec(cols)]
+      index_name ||= idx_name(@origin.name, cols)
+      parts = [type, index_name, @name, idx_spec(cols)]
       "create %s `%s` on `%s` (%s)" % parts
     end
   end

spec/integration/integration_helper.rb

@@ -99,10 +99,15 @@ def count_all(table)
     select_value(query).to_i
   end
 
-  def key?(table_name, cols, type = :non_unique)
-    non_unique = type == :non_unique ? 1 : 0
+  def index_on_columns?(table_name, cols, type = :non_unique)
     key_name = Lhm::SqlHelper.idx_name(table_name, cols)
 
+    index?(table_name, key_name, type)
+  end
+
+  def index?(table_name, key_name, type = :non_unique)
+    non_unique = type == :non_unique ? 1 : 0
+
     !!select_value(%Q<
       show indexes in #{ table_name }
      where key_name = '#{ key_name }'

spec/integration/lhm_spec.rb

@@ -57,7 +57,17 @@
       end
 
       slave do
-        key?(:users, [:comment, :created_at]).must_equal(true)
+        index_on_columns?(:users, [:comment, :created_at]).must_equal(true)
+      end
+    end
+
+    it "should add an index with a custom name" do
+      Lhm.change_table(:users) do |t|
+        t.add_index([:comment, :created_at], :my_index_name)
+      end
+
+      slave do
+        index?(:users, :my_index_name).must_equal(true)
       end
     end
 
@@ -67,7 +77,7 @@
       end
 
       slave do
-        key?(:users, :group).must_equal(true)
+        index_on_columns?(:users, :group).must_equal(true)
       end
     end
 
@@ -77,7 +87,7 @@
       end
 
       slave do
-        key?(:users, :comment, :unique).must_equal(true)
+        index_on_columns?(:users, :comment, :unique).must_equal(true)
       end
     end
 
@@ -87,7 +97,17 @@
       end
 
       slave do
-        key?(:users, [:username, :created_at]).must_equal(false)
+        index_on_columns?(:users, [:username, :created_at]).must_equal(false)
+      end
+    end
+
+    it "should remove an index with a custom name" do
+      Lhm.change_table(:users) do |t|
+        t.remove_index(:reference, :index_users_on_reference)
+      end
+
+      slave do
+        index?(:users, :index_users_on_reference).must_equal(false)
       end
     end
 

spec/unit/migrator_spec.rb

@@ -16,36 +16,68 @@
 
   describe "index changes" do
     it "should add an index" do
-      @creator.add_index(["a", "b"])
+      @creator.add_index(:a)
+
+      @creator.statements.must_equal([
+        "create index `index_alt_on_a` on `lhmn_alt` (`a`)"
+      ])
+    end
+
+    it "should add a composite index" do
+      @creator.add_index([:a, :b])
 
       @creator.statements.must_equal([
         "create index `index_alt_on_a_and_b` on `lhmn_alt` (`a`, `b`)"
       ])
     end
 
-    it "should add an index with prefixed columns" do
+    it "should add an index with prefix length" do
       @creator.add_index(["a(10)", "b"])
 
       @creator.statements.must_equal([
         "create index `index_alt_on_a_and_b` on `lhmn_alt` (`a`(10), `b`)"
       ])
     end
 
-    it "should add an unique index" do
+    it "should add an index with a custom name" do
+      @creator.add_index([:a, :b], :custom_index_name)
+
+      @creator.statements.must_equal([
+        "create index `custom_index_name` on `lhmn_alt` (`a`, `b`)"
+      ])
+    end
+
+    it "should add a unique index" do
       @creator.add_unique_index(["a(5)", :b])
 
       @creator.statements.must_equal([
         "create unique index `index_alt_on_a_and_b` on `lhmn_alt` (`a`(5), `b`)"
       ])
     end
 
+    it "should add a unique index with a custom name" do
+      @creator.add_unique_index([:a, :b], :custom_index_name)
+
+      @creator.statements.must_equal([
+        "create unique index `custom_index_name` on `lhmn_alt` (`a`, `b`)"
+      ])
+    end
+
     it "should remove an index" do
       @creator.remove_index(["b", "a"])
 
       @creator.statements.must_equal([
         "drop index `index_alt_on_b_and_a` on `lhmn_alt`"
       ])
     end
+
+    it "should remove an index with a custom name" do
+      @creator.remove_index([:a, :b], :custom_index_name)
+
+      @creator.statements.must_equal([
+        "drop index `custom_index_name` on `lhmn_alt`"
+      ])
+    end
   end
 
   describe "column changes" do