Allow URI connection string

(Imported from #3)

lib/pg/connection.rb

@@ -1,6 +1,7 @@
 #!/usr/bin/env ruby
 
 require 'pg' unless defined?( PG )
+require 'uri'
 
 # The PostgreSQL connection class. The interface for this class is based on
 # {libpq}[http://www.postgresql.org/docs/9.2/interactive/libpq.html], the C
@@ -34,46 +35,55 @@ def self::quote_connstr( value )
 	def self::parse_connect_args( *args )
 		return '' if args.empty?
 
-		# This will be swapped soon for code that makes options like those required for
-		# PQconnectdbParams()/PQconnectStartParams(). For now, stick to an options string for
-		# PQconnectdb()/PQconnectStart().
+		hash_arg = args.last.is_a?( Hash ) ? args.pop : {}
+		option_string = ''
+		options = {}
 
 		# Parameter 'fallback_application_name' was introduced in PostgreSQL 9.0
 		# together with PQescapeLiteral().
-		if PG::Connection.instance_methods.find{|m| m.to_sym == :escape_literal }
-			appname = $0.sub(/^(.{30}).{4,}(.{30})$/){ $1+"..."+$2 }
-			appname = PG::Connection.quote_connstr( appname )
-			connopts = ["fallback_application_name=#{appname}"]
-		else
-			connopts = []
+		if PG::Connection.instance_methods.find {|m| m.to_sym == :escape_literal }
+			options[:fallback_application_name] = $0.sub( /^(.{30}).{4,}(.{30})$/ ){ $1+"..."+$2 }
 		end
 
-		# Handle an options hash first
-		if args.last.is_a?( Hash )
-			opthash = args.pop
-			opthash.each do |key, val|
-				connopts.push( "%s=%s" % [key, PG::Connection.quote_connstr(val)] )
+		if args.length == 1
+			case args.first
+			when URI, URI.regexp
+				uri = URI(args.first)
+				options.merge!( Hash[URI.decode_www_form( uri.query )] ) if uri.query
+			when /=/
+				# Option string style
+				option_string = args.first.to_s
+			else
+				# Positional parameters
+				options[CONNECT_ARGUMENT_ORDER.first.to_sym] = args.first
 			end
-		end
-
-		# Option string style
-		if args.length == 1 && args.first.to_s.index( '=' )
-			connopts.unshift( args.first )
-
-		# Append positional parameters
 		else
-			args.each_with_index do |val, i|
-				next unless val # Skip nil placeholders
+			max = CONNECT_ARGUMENT_ORDER.length
+			raise ArgumentError,
+				"Extra positional parameter %d: %p" % [ max + 1, args[max] ] if args.length > max
 
-				key = CONNECT_ARGUMENT_ORDER[ i ] or
-					raise ArgumentError, "Extra positional parameter %d: %p" % [ i+1, val ]
-				connopts.push( "%s=%s" % [key, PG::Connection.quote_connstr(val.to_s)] )
+			CONNECT_ARGUMENT_ORDER.zip( args ) do |(k,v)|
+				options[ k.to_sym ] = v if v
 			end
 		end
 
-		return connopts.join(' ')
+		options.merge!( hash_arg )
+
+		if uri
+			uri.host     = nil if options[:host]
+			uri.port     = nil if options[:port]
+			uri.user     = nil if options[:user]
+			uri.password = nil if options[:password]
+			uri.path     = '' if options[:dbname]
+			uri.query    = URI.encode_www_form( options )
+			return uri.to_s.sub( /^#{uri.scheme}:(?!\/\/)/, "#{uri.scheme}://" )
+		else
+			option_string += ' ' unless option_string.empty? && options.empty?
+			return option_string + options.map { |k,v| "#{k}=#{quote_connstr(v)}" }.join( ' ' )
+		end
 	end
 
+
 	#  call-seq:
 	#     conn.copy_data( sql ) {|sql_result| ... } -> PG::Result
 	#

spec/pg/connection_spec.rb

@@ -45,13 +45,69 @@
 		expect( optstring ).to match( /(^|\s)user='jrandom'/ )
 	end
 
+	it "can create a connection option string from an option string and a hash" do
+		optstring = described_class.parse_connect_args( 'dbname=original', :user => 'jrandom' )
+
+		expect( optstring ).to be_a( String )
+		expect( optstring ).to match( /(^|\s)dbname=original/ )
+		expect( optstring ).to match( /(^|\s)user='jrandom'/ )
+	end
+
 	it "escapes single quotes and backslashes in connection parameters" do
 		expect(
 			described_class.parse_connect_args( "DB 'browser' \\" )
 		).to match( /host='DB \\'browser\\' \\\\'/ )
 
 	end
 
+	let(:uri) { 'postgresql://user:pass@pgsql.example.com:222/db01?sslmode=require' }
+
+	it "can connect using a URI" do
+		string = described_class.parse_connect_args(uri)
+
+		expect( string ).to be_a( String )
+		expect( string ).to match( %r{^postgresql://user:pass@pgsql.example.com:222/db01\?} )
+		expect( string ).to match( %r{\?.*sslmode=require} )
+
+		string = described_class.parse_connect_args(URI.parse(uri))
+
+		expect( string ).to be_a( String )
+		expect( string ).to match( %r{^postgresql://user:pass@pgsql.example.com:222/db01\?} )
+		expect( string ).to match( %r{\?.*sslmode=require} )
+	end
+
+	it "can create a connection URI from a URI and a hash" do
+		string = described_class.parse_connect_args(uri, :connect_timeout => 2)
+
+		expect( string ).to be_a( String )
+		expect( string ).to match( %r{^postgresql://user:pass@pgsql.example.com:222/db01\?} )
+		expect( string ).to match( %r{\?.*sslmode=require} )
+		expect( string ).to match( %r{\?.*connect_timeout=2} )
+
+		string = described_class.parse_connect_args(uri, :user => 'a', :password => 'b', :host => 'localhost', :port => 555, :dbname => 'x')
+
+		expect( string ).to be_a( String )
+		expect( string ).to match( %r{^postgresql://\?} )
+		expect( string ).to match( %r{\?.*user=a} )
+		expect( string ).to match( %r{\?.*password=b} )
+		expect( string ).to match( %r{\?.*host=localhost} )
+		expect( string ).to match( %r{\?.*port=555} )
+		expect( string ).to match( %r{\?.*dbname=x} )
+	end
+
+	it "can create a connection URI with a non-standard domain socket directory" do
+		string = described_class.parse_connect_args('postgresql://%2Fvar%2Flib%2Fpostgresql/dbname')
+
+		expect( string ).to be_a( String )
+		expect( string ).to match( %r{^postgresql://%2Fvar%2Flib%2Fpostgresql/dbname} )
+
+		string = described_class.parse_connect_args('postgresql:///dbname', :host => '/var/lib/postgresql')
+
+		expect( string ).to be_a( String )
+		expect( string ).to match( %r{^postgresql:///dbname\?} )
+		expect( string ).to match( %r{\?.*host=%2Fvar%2Flib%2Fpostgresql} )
+	end
+
 	it "connects with defaults if no connection parameters are given" do
 		expect( described_class.parse_connect_args ).to eq( '' )
 	end
@@ -89,8 +145,13 @@
 
 	it "raises an exception when connecting with an invalid number of arguments" do
 		expect {
-			described_class.connect( 1, 2, 3, 4, 5, 6, 7, 'extra' )
-		}.to raise_error( ArgumentError, /extra positional parameter/i )
+			described_class.connect( 1, 2, 3, 4, 5, 6, 7, 'the-extra-arg' )
+		}.to raise_error do |error|
+			expect( error ).to be_an( ArgumentError )
+			expect( error.message ).to match( /extra positional parameter/i )
+			expect( error.message ).to match( /8/ )
+			expect( error.message ).to match( /the-extra-arg/ )
+		end
 	end
 
 	it "can connect asynchronously", :socket_io do