Remove an extra my from Shop::Cart.

Add the getTaxRates method to Tax, with tests.
Add some calculate code to Tax, with tests, which don't pass yet.

lib/WebGUI/Shop/Cart.pm

@@ -72,7 +72,7 @@ sub create {
     }
     my $cartId = $session->db->quickScalar("select cartId from cart where sessionId=?",[$session->getId]);
     return $class->new($session, $cartId) if (defined $cartId);
-    my $cartId = $session->id->generate;
+    $cartId = $session->id->generate;
     $session->db->write('insert into cart (cartId, sessionId) values (?,?)', [$cartId, $session->getId]);
     return $class->new($session, $cartId);
 }

lib/WebGUI/Shop/Tax.pm

@@ -6,6 +6,11 @@ use Class::InsideOut qw{ :std };
 use WebGUI::Text;
 use WebGUI::Storage;
 use WebGUI::Exception::Shop;
+use WebGUI::Shop::Cart;
+use WebGUI::Shop::CartItem;
+use WebGUI::Shop::AddressBook;
+use WebGUI::Shop::Address;
+use List::Util qw{sum};
 
 =head1 NAME
 
@@ -89,7 +94,23 @@ sub calculate {
     my $cart = shift;
     WebGUI::Error::InvalidParam->throw(error => 'Must pass in a WebGUI::Shop::Cart object')
         unless ref($cart) eq 'WebGUI::Shop::Cart';
-    return;
+    my $book = WebGUI::Shop::AddressBook->create($self->session);
+    my $address = WebGUI::Shop::Address->new($book, $cart->get('shippingAddressId'));
+    my $tax = 0;
+    foreach my $item (@{ $cart->getItems }) {
+        my $sku = $item->getSku;
+        my $unitPrice = $sku->getPrice;
+        my $quantity  = $item->get('quantity');
+        my $taxables  = $self->getTaxRates($address);
+        use Data::Dumper;
+        warn Dumper $taxables;
+        my $itemTax   = sum(@{$taxables}) / 100;  ##Form a percentage
+        warn "unitPrice: $unitPrice\n";
+        warn "quantity : $quantity\n";
+        warn "itemTax  : $itemTax\n";
+        $tax += $unitPrice * $quantity * $itemTax;
+    }
+    return $tax;
 }
 
 #-------------------------------------------------------------------
@@ -160,6 +181,30 @@ sub getItems {
 
 #-------------------------------------------------------------------
 
+=head2 getTaxRates ( $address )
+
+Given a WebGUI::Shop::Address object, return all rates associated with the address as an arrayRef.
+
+=cut
+
+sub getTaxRates {
+    my $self = shift;
+    my $address = shift;
+    WebGUI::Error::InvalidObject->throw(error => 'Need an address.', expected=>'WebGUI::Shop::Address', got=>(ref $address))
+        unless ref($address) eq 'WebGUI::Shop::Address';
+    my $result = $self->session->db->buildArrayRef(
+    q{
+        select taxRate from tax where
+           (field='state'   and value=?)
+        OR (field='country' and value=?)
+        OR (field='code'    and value=?)
+    },
+    [$address->get('state'), $address->get('country'), $address->get('code')]);
+    return $result;
+}
+
+#-------------------------------------------------------------------
+
 =head2 importTaxData ( $filePath )
 
 Import tax information from the specified file in CSV format.  The

t/Shop/Tax.t

@@ -23,6 +23,8 @@ use Exception::Class;
 use WebGUI::Test; # Must use this before any other WebGUI modules
 use WebGUI::Session;
 use WebGUI::Text;
+use WebGUI::Shop::Cart;
+use WebGUI::Shop::AddressBook;
 
 #----------------------------------------------------------------------------
 # Init
@@ -31,7 +33,7 @@ my $session         = WebGUI::Test->session;
 #----------------------------------------------------------------------------
 # Tests
 
-my $tests = 64;
+my $tests = 68;
 plan tests => 1 + $tests;
 
 #----------------------------------------------------------------------------
@@ -366,6 +368,57 @@ cmp_deeply(
     'importTaxData: error handling for file that that cannot be read',
 );
 
+#######################################################################
+#
+# getTaxRates
+#
+#######################################################################
+
+##Set up the tax information
+$taxer->importTaxData(
+    WebGUI::Test->getTestCollateralPath('taxTables/largeTaxTable.csv')
+),
+my $book = WebGUI::Shop::AddressBook->create($session);
+my $taxingAddress = $book->addAddress({
+    label => 'taxing',
+    city  => 'Madison',
+    state => 'WI',
+    code  => '53701',
+    country => 'USA',
+});
+my $taxFreeAddress = $book->addAddress({
+    label => 'no tax',
+    city  => 'Portland',
+    state => 'OR',
+    code  => '97123',
+    country => 'USA',
+});
+
+eval { $taxer->getTaxRates(); };
+$e = Exception::Class->caught();
+isa_ok($e, 'WebGUI::Error::InvalidObject', 'calculate: error handling for not sending a cart');
+cmp_deeply(
+    $e,
+    methods(
+        error => 'Need an address.',
+        got   => '',
+        expected => 'WebGUI::Shop::Address',
+    ),
+    'importTaxData: error handling for file that does not exist in the filesystem',
+);
+
+cmp_deeply(
+    $taxer->getTaxRates($taxingAddress),
+    [5, 0.5],
+    'getTaxRates: return correct data for a state with tax data'
+);
+
+cmp_deeply(
+    $taxer->getTaxRates($taxFreeAddress),
+    [0.0],
+    'getTaxRates: return correct data for a state with no tax data'
+);
+
 #######################################################################
 #
 # calculate
@@ -379,6 +432,32 @@ is($e->error, 'Must pass in a WebGUI::Shop::Cart object', 'calculate: error hand
 
 ##Build a cart, add some Donation SKUs to it.  Set one to be taxable.
 
+my $cart = WebGUI::Shop::Cart->create($session);
+$cart->update({ shippingAddressId => $taxingAddress->getId});
+
+##Set up the tax information
+$taxer->importTaxData(
+    WebGUI::Test->getTestCollateralPath('taxTables/goodTaxTable.csv')
+),
+
+my $taxableDonation = WebGUI::Asset->getRoot($session)->addChild({
+    className => 'WebGUI::Asset::Sku::Donation',
+    title     => 'Taxable donation',
+    defaultPrice => 100.00,
+});
+
+$cart->addItem($taxableDonation);
+
+foreach my $item (@{ $cart->getItems }) {
+    $item->setQuantity(1);
+}
+
+my $tax = $taxer->calculate($cart);
+is($tax, 5.5, 'calculate: simple tax calculation on 1 item in the cart');
+
+$taxableDonation->purge;
+$cart->delete;
+$book->delete;
 }
 
 sub _grabTaxData {
@@ -395,5 +474,8 @@ sub _grabTaxData {
 # Cleanup
 END {
     $session->db->write('delete from tax');
+    $session->db->write('delete from cart');
+    $session->db->write('delete from addressBook');
+    $session->db->write('delete from address');
     $storage->delete;
 }

t/supporting_collateral/taxTables/largeTaxTable.csv

@@ -0,0 +1,8 @@
+field,value,taxRate
+state,WI,5.0
+code,53701,0.5
+code,53702,0.5
+code,53703,0.5
+code,53704,0.5
+state,CA,7.25
+code,97123,0.0