Custom name for index

spec/migrator/create_index_statement_spec.cr

@@ -13,4 +13,11 @@ describe Avram::Migrator::CreateIndexStatement do
     statement = Avram::Migrator::CreateIndexStatement.new(:users, columns: [:email, :username], using: :btree, unique: true).build
     statement.should eq "CREATE UNIQUE INDEX users_email_username_index ON users USING btree (email, username);"
   end
+
+  context "custom index name" do
+    it "generates correct CREATE INDEX sql with given name" do
+      statement = Avram::Migrator::CreateIndexStatement.new(:users, :email, name: :custom_index_name).build
+      statement.should eq "CREATE INDEX custom_index_name ON users USING btree (email);"
+    end
+  end
 end

spec/migrator/drop_index_statement_spec.cr

@@ -10,4 +10,20 @@ describe Avram::Migrator::DropIndexStatement do
     statement = Avram::Migrator::DropIndexStatement.new(:users, [:email, :username], on_delete: :cascade, if_exists: true).build
     statement.should eq "DROP INDEX IF EXISTS users_email_username_index CASCADE;"
   end
+
+  context "custom index name" do
+    it "generates correct sql with given name" do
+      statement = Avram::Migrator::DropIndexStatement.new(:users, name: :custom_index_name).build
+      statement.should eq "DROP INDEX custom_index_name;"
+    end
+  end
+
+  context "without name and columns" do
+    it "raises Exception" do
+      message = Regex.new("No name or columns specified for drop_index")
+      expect_raises(Exception, message) do
+        statement = Avram::Migrator::DropIndexStatement.new(:users).build
+      end
+    end
+  end
 end

src/avram/migrator/create_index_statement.cr

@@ -23,15 +23,18 @@ class Avram::Migrator::CreateIndexStatement
 
   ALLOWED_INDEX_TYPES = %w[btree]
 
-  def initialize(@table : Symbol, @columns : Columns, @using : Symbol = :btree, @unique = false)
+  def initialize(@table : Symbol, @columns : Columns, @using : Symbol = :btree, @unique = false, @name : String? | Symbol? = nil)
     raise "index type '#{using}' not supported" unless ALLOWED_INDEX_TYPES.includes?(using.to_s)
   end
 
   def build
+    index_name = @name
+    index_name ||= "#{@table}_#{columns.join("_")}_index"
+
     String.build do |index|
       index << "CREATE"
       index << " UNIQUE" if @unique
-      index << " INDEX #{@table}_#{columns.join("_")}_index"
+      index << " INDEX #{index_name}"
       index << " ON #{@table}"
       index << " USING #{@using}"
       index << " (#{columns.join(", ")});"

src/avram/migrator/drop_index_statement.cr

@@ -22,14 +22,14 @@ class Avram::Migrator::DropIndexStatement
 
   ALLOWED_ON_DELETE_STRATEGIES = %i[cascade restrict]
 
-  def initialize(@table : Symbol, @columns : Columns, @if_exists = false, @on_delete = :do_nothing)
+  def initialize(@table : Symbol, @columns : Columns | Nil = nil, @if_exists = false, @on_delete = :do_nothing, @name : String? | Symbol? = nil)
   end
 
   def build
     String.build do |index|
       index << "DROP INDEX"
       index << " IF EXISTS" if @if_exists
-      index << " #{@table}_#{columns.join("_")}_index"
+      index << " #{index_name}"
       index << on_delete_strategy(@on_delete)
     end
   end
@@ -53,4 +53,14 @@ class Avram::Migrator::DropIndexStatement
       return [columns]
     end
   end
+
+  private def index_name
+    if @name
+      @name
+    elsif @columns
+      "#{@table}_#{columns.join("_")}_index"
+    else
+      raise "No name or columns specified for drop_index"
+    end
+  end
 end

src/avram/migrator/statement_helpers.cr

@@ -32,12 +32,12 @@ module Avram::Migrator::StatementHelpers
     prepared_statements << CreateForeignKeyStatement.new(from, to, on_delete, column, primary_key).build
   end
 
-  def create_index(table_name : Symbol, columns : Columns, unique = false, using = :btree)
-    prepared_statements << CreateIndexStatement.new(table_name, columns, using, unique).build
+  def create_index(table_name : Symbol, columns : Columns, unique = false, using = :btree, name : String? | Symbol? = nil)
+    prepared_statements << CreateIndexStatement.new(table_name, columns, using, unique, name).build
   end
 
-  def drop_index(table_name : Symbol, columns : Columns, if_exists = false, on_delete = :do_nothing)
-    prepared_statements << Avram::Migrator::DropIndexStatement.new(table_name, columns, if_exists, on_delete).build
+  def drop_index(table_name : Symbol, columns : Columns? = nil, if_exists = false, on_delete = :do_nothing, name : String? | Symbol? = nil)
+    prepared_statements << Avram::Migrator::DropIndexStatement.new(table_name, columns, if_exists, on_delete, name).build
   end
 
   def make_required(table : Symbol, column : Symbol)