shared which helper (inspired by Warbler's PlatformHelper) - win support

Author: kares

rakelib/db.rake

@@ -4,6 +4,7 @@ namespace :db do
 
   desc "Creates the test database for MySQL"
   task :mysql do
+    fail "could not create test database: mysql executable not found" unless mysql = which('mysql')
     load 'test/db/mysql_config.rb' # rescue nil
     script = sql_script <<-SQL, 'mysql'
 DROP DATABASE IF EXISTS `#{MYSQL_CONFIG[:database]}`;
@@ -19,12 +20,13 @@ SQL
       params['--password'] = password
     end
     puts "Creating MySQL (test) database: #{MYSQL_CONFIG[:database]}"
-    sh "cat #{script.path} | mysql #{params.to_a.join(' ')}", :verbose => $VERBOSE # so password is not echoed
+    sh "cat #{script.path} | #{mysql} #{params.to_a.join(' ')}", :verbose => $VERBOSE # so password is not echoed
   end
 
   desc "Creates the test database for PostgreSQL"
   task :postgresql do
-    fail unless PostgresHelper.have_postgres?
+    fail 'could not create test database: psql executable not found' unless psql = which('psql')
+    fail 'could not create test database: missing "postgres" role' unless PostgresHelper.postgres_role?
     load 'test/db/postgres_config.rb' # rescue nil
     script = sql_script <<-SQL, 'psql'
 DROP DATABASE IF EXISTS #{POSTGRES_CONFIG[:database]};
@@ -35,7 +37,7 @@ SQL
     params = { '-U' => ENV['PSQL_USER'] || 'postgres' }
     params['-q'] = nil unless $VERBOSE
     puts "Creating PostgreSQL (test) database: #{POSTGRES_CONFIG[:database]}"
-    sh "cat #{script.path} | psql #{params.to_a.join(' ')}", :verbose => $VERBOSE
+    sh "cat #{script.path} | #{psql} #{params.to_a.join(' ')}", :verbose => $VERBOSE
   end
   task :postgres => :postgresql
 

test/db/mssql/rake_test.rb

@@ -11,7 +11,7 @@ def db_config
   def do_teardown
     drop_rake_test_database(:silence)
   end
-  
+
   test 'rake db:create (and db:drop)' do
     begin
       Rake::Task["db:create"].invoke
@@ -35,13 +35,13 @@ def do_teardown
     drop_rake_test_database(:silence)
     Rake::Task["db:drop"].invoke
   end
-  
+
   test 'rake db:test:purge' do
     # Rake::Task["db:create"].invoke
     create_rake_test_database do |connection|
       connection.create_table('users') { |t| t.string :name }
     end
-    
+
     Rake::Task["db:test:purge"].invoke
 
     ActiveRecord::Base.establish_connection db_config.merge :database => db_name
@@ -50,27 +50,27 @@ def do_teardown
   end
 
   test 'rake db:structure:dump (and db:structure:load)' do
-    omit('smoscript not available') unless self.class.find_executable?('smoscript')
+    omit('smoscript not available') unless self.class.which('smoscript')
     # Rake::Task["db:create"].invoke
     create_rake_test_database do |connection|
       create_schema_migrations_table(connection)
       connection.create_table('users') { |t| t.string :name; t.timestamps }
     end
-    
+
     structure_sql = File.join('db', structure_sql_filename)
     begin
       Dir.mkdir 'db' # db/structure.sql
       Rake::Task["db:structure:dump"].invoke
-      
+
       assert File.exists?(structure_sql)
       # CREATE TABLE [dbo].[users]( ... )
       assert_match /CREATE TABLE .*?\[users\]/i, File.read(structure_sql)
-      
+
       # db:structure:load
       drop_rake_test_database(:silence)
       create_rake_test_database
       Rake::Task["db:structure:load"].invoke
-      
+
       ActiveRecord::Base.establish_connection db_config.merge :database => db_name
       assert ActiveRecord::Base.connection.table_exists?('users')
       ActiveRecord::Base.connection.disconnect!
@@ -79,12 +79,12 @@ def do_teardown
       Dir.rmdir 'db'
     end
   end
-  
+
   setup { rm_r 'db' if File.exist?('db') }
-  
+
   test 'rake db:charset' do
     create_rake_test_database
-    # using the default character set, the character_set_name should be 
+    # using the default character set, the character_set_name should be
     # iso_1 (ISO 8859-1) for the char and varchar data types
     expect_rake_output /iso_1|UCS/i
     Rake::Task["db:charset"].invoke
@@ -96,7 +96,7 @@ def do_teardown
     expect_rake_output /SQL_.*/
     Rake::Task["db:collation"].invoke
   end
-  
+
   # @override
   def create_rake_test_database(db_name = self.db_name)
     ActiveRecord::Base.establish_connection db_config
@@ -105,14 +105,14 @@ def create_rake_test_database(db_name = self.db_name)
       # connection.use_database('master')
       connection.create_database(db_name, db_config)
     end
-    
+
     if block_given?
       ActiveRecord::Base.establish_connection db_config.merge :database => db_name
       yield ActiveRecord::Base.connection
     end
     ActiveRecord::Base.connection.disconnect!
   end
-  
+
   # @override
   def drop_rake_test_database(silence = false)
     ActiveRecord::Base.establish_connection db_config
@@ -128,9 +128,9 @@ def drop_rake_test_database(silence = false)
     end
     ActiveRecord::Base.connection.disconnect!
   end
-  
+
   private
-  
+
   def databases
     if ActiveRecord::Base.connection.send(:sqlserver_2000?)
       select = "SELECT name FROM master..sysdatabases ORDER BY name"
@@ -139,5 +139,5 @@ def databases
     end
     ActiveRecord::Base.connection.select_rows(select).flatten
   end
-  
+
 end

test/db/mysql/rake_test.rb

@@ -12,23 +12,24 @@ def do_teardown
     drop_rake_test_database(:silence)
   end
 
+  MYSQL_EXE = which('mysql')
+
   test 'rake db:create (and db:drop)' do
-    # omit_unless find_executable?("mysql")
     Rake::Task["db:create"].invoke
     with_mysql do |mysql|
       mysql << "show databases where `Database` = '#{db_name}';"
       mysql.close_write
       output = mysql.read
       assert output =~ /#{db_name}/m, "db name: #{db_name.inspect} not matched in:\n#{output}"
-    end if find_executable?("mysql")
+    end if MYSQL_EXE
 
     Rake::Task["db:drop"].invoke
     with_mysql do |mysql|
       mysql << "show databases where `Database` = '#{db_name}';"
       mysql.close_write
       output = mysql.read
       assert_nil output =~ /#{db_name}/m, "db name: #{db_name.inspect} matched in:\n#{output}"
-    end if find_executable?("mysql")
+    end if MYSQL_EXE
   end
 
   test 'rake db:test:purge' do
@@ -116,7 +117,7 @@ def do_teardown
   private
 
   def with_mysql(args = nil)
-    exec = "mysql -u #{db_config[:username]} --password=#{db_config[:password]} #{args}"
+    exec = "#{MYSQL_EXE} -u #{db_config[:username]} --password=#{db_config[:password]} #{args}"
     IO.popen(exec, "r+") { |mysql| yield(mysql) }
   end
 

test/db/postgresql/rake_test.rb

@@ -12,17 +12,17 @@ def do_teardown
     drop_rake_test_database(:silence)
   end
 
-  PSQL_EXECUTABLE = find_executable?("psql")
+  PSQL_EXE = which('psql')
 
   test 'rake db:create (and db:drop)' do
     Rake::Task["db:create"].invoke
-    if PSQL_EXECUTABLE
+    if PSQL_EXE
       output = psql("-d template1 -c '\\\l'")
       assert_match /#{db_name}/m, output
     end
 
     Rake::Task["db:drop"].invoke
-    if PSQL_EXECUTABLE
+    if PSQL_EXE
       output = psql("-d template1 -c '\\\l'")
       assert_no_match /#{db_name}/m, output
     end
@@ -73,7 +73,7 @@ def do_teardown
   end
 
   test 'rake db:structure:dump (and db:structure:load)' do
-    omit('pg_dump not available') unless self.class.find_executable?('pg_dump')
+    omit('pg_dump not available') unless self.class.which('pg_dump')
     # Rake::Task["db:create"].invoke
     create_rake_test_database do |connection|
       create_schema_migrations_table(connection)
@@ -137,7 +137,7 @@ def psql(args)
     if username = ENV['PSQL_USERNAME']
       args = "--username=#{username} #{args}"
     end
-    `psql #{args}`
+    `#{PSQL_EXE} #{args}`
   end
 
 end

test/db/sqlite3/rake_test.rb

@@ -36,7 +36,7 @@ def do_teardown
   end
 
   test 'rake db:structure:dump (and db:structure:load)' do
-    omit('sqlite3 not available') unless self.class.find_executable?('sqlite3')
+    omit('sqlite3 not available') unless self.class.which('sqlite3')
     create_rake_test_database do |connection|
       create_schema_migrations_table(connection)
       connection.create_table('users') { |t| t.string :name; t.timestamps }

test/shared_helper.rb

@@ -1,35 +1,50 @@
-# Defining helper methods useful both in the definition of test tasks, as well as in the execution
-# of tests themselves.  Do not require test/unit within this file, as that'll make the rake process
-# attempt to run tests itself.  Test-specific helpers should go in test/jdbc_common.rb.
+# Helpers useful both in the definition of test tasks, as well as in tests.
+
+require 'fileutils'
 
 module Kernel
-  def find_executable?(name)
-    (ENV['PATH'] || '').split(File::PATH_SEPARATOR).
-      detect { |p| File.executable?(File.join(p, name)) }
+
+  # Cross-platform way of finding an executable in the $PATH.
+  # Thanks to @mislav
+  #
+  # which('ruby') #=> /usr/bin/ruby
+  def which(cmd)
+    exts = ENV['PATHEXT'] ? ENV['PATHEXT'].split(';') : ['']
+    ( ENV['PATH'] || '' ).split(File::PATH_SEPARATOR).each do |path|
+      exts.each do |ext|
+        exe = File.join(path, "#{cmd}#{ext}")
+        return exe if File.executable? exe
+      end
+    end
+    nil
   end
+
 end
 
 module PostgresHelper
-  def self.pg_cmdline_params
-    params = ""
-    params += "-h #{ENV['PGHOST']} " if ENV['PGHOST']
-    params += "-p #{ENV['PGPORT']} " if ENV['PGPORT']
-    params
-  end
-
-  def self.have_postgres?(warn = nil)
-    if find_executable?("psql")
-      if `psql -c '\\l' -U postgres #{pg_cmdline_params}2>&1` && $?.exitstatus == 0
-        true
-      else
-        if warn.nil?
-          warn = "No \"postgres\" role? You might need to execute `createuser postgres -drs' first."
+  class << self
+    def postgres_role?(warn = nil)
+      if psql = which('psql')
+        if `#{psql} -c '\\l' -U postgres #{psql_params}2>&1` && $?.exitstatus == 0
+          true
+        else
+          if warn.nil?
+            warn = "No \"postgres\" role? You might need to execute `createuser postgres -drs' first."
+          end
+          send(:warn, warn) if warn # warn == false disables warnings
+          false
         end
-        send(:warn, warn) if warn # warn == false disables warnings
-        false
       end
     end
+    alias_method :have_postgres?, :postgres_role?
+
+    private
+
+    def psql_params
+      params = ""
+      params << "-h #{ENV['PGHOST']} " if ENV['PGHOST']
+      params << "-p #{ENV['PGPORT']} " if ENV['PGPORT']
+      params
+    end
   end
 end
-
-require 'fileutils'