Evolve the member discount into a sitewide stepped promo

Replaces the flat "$10 off $100+, members only" discount with $5 off
per $50 spent, capped at $200 spend ($20 max) — an evolution of the
same idea, not an addition to it. Now sitewide by default: the guest
tier carries the same step_discount benefit as free_member, so
anonymous shoppers get it too, not just members. Toggling it on/off, or
switching between sitewide and members-only, needs no code change — an
admin unchecks the benefit on one tier's row in the settings screen.

Migration (schema v3->v4) overwrites guest/free_member's benefits to the
new shape directly rather than merging, per the established pre-launch
convention (no real customer/tier data exists to preserve yet).

Live-verified beyond the unit suite: the full discount table checked
against the real DB for both a guest and a real member, and the
sitewide/members-only toggle exercised through a real authenticated
settings-screen form POST (not just read back from code).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MqhgnCRjjVLFnZ3Jpn93Vg

wp-content/plugins/bookstore-core/bookstore-core.php

@@ -13,7 +13,7 @@ defined('ABSPATH') || exit;
 define('BSC_PLUGIN_FILE', __FILE__);
 define('BSC_PLUGIN_DIR', plugin_dir_path(__FILE__));
 define('BSC_VERSION', '0.2.0');
-define('BSC_SCHEMA_VERSION', '3');
+define('BSC_SCHEMA_VERSION', '4');
 
 spl_autoload_register(function (string $class) {
     $prefix = 'Bookstore\\Core\\';

wp-content/plugins/bookstore-core/includes/Admin/TierSettings.php

@@ -58,7 +58,7 @@ class TierSettings extends \WC_Settings_Page
                 </tr>
             </thead>
             <tbody>
-                <?php foreach ($tiers as $tier): $fs = $tier['benefits']['free_shipping_threshold'] ?? null; $sd = $tier['benefits']['spend_discount'] ?? null; ?>
+                <?php foreach ($tiers as $tier): $fs = $tier['benefits']['free_shipping_threshold'] ?? null; $sd = $tier['benefits']['step_discount'] ?? null; ?>
                 <tr>
                     <td>
                         <input type="text" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][name]" value="<?php echo esc_attr($tier['name']); ?>" />
@@ -72,9 +72,10 @@ class TierSettings extends \WC_Settings_Page
                         $<input type="number" step="0.01" style="width:6em" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][free_shipping_threshold][threshold]" value="<?php echo esc_attr($fs['threshold'] ?? '0.00'); ?>" />
                     </td>
                     <td>
-                        <label><input type="checkbox" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][spend_discount][enabled]" value="1" <?php checked($sd !== null); ?> /> enabled</label><br>
+                        <label><input type="checkbox" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][step_discount][enabled]" value="1" <?php checked($sd !== null); ?> /> enabled</label><br>
-                        save $<input type="number" step="0.01" style="width:6em" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][spend_discount][discount_amount]" value="<?php echo esc_attr($sd['discount_amount'] ?? '0.00'); ?>" />
+                        $<input type="number" step="0.01" style="width:5em" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][step_discount][discount_per_step]" value="<?php echo esc_attr($sd['discount_per_step'] ?? '0.00'); ?>" />
-                        on orders $<input type="number" step="0.01" style="width:6em" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][spend_discount][min_spend]" value="<?php echo esc_attr($sd['min_spend'] ?? '0.00'); ?>" />+
+                        off per $<input type="number" step="0.01" style="width:5em" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][step_discount][step_amount]" value="<?php echo esc_attr($sd['step_amount'] ?? '0.00'); ?>" />
+                        spent, capped at $<input type="number" step="0.01" style="width:6em" name="bsc_tier[<?php echo esc_attr($tier['tier_id']); ?>][step_discount][max_spend]" value="<?php echo esc_attr($sd['max_spend'] ?? '0.00'); ?>" />
                     </td>
                     <td>
                         <?php if ($tier['slug'] !== Tier::GUEST_SLUG): ?>
@@ -125,10 +126,11 @@ class TierSettings extends \WC_Settings_Page
                         'threshold' => (float) ($fields['free_shipping_threshold']['threshold'] ?? 0),
                     ];
                 }
-                if (!empty($fields['spend_discount']['enabled'])) {
+                if (!empty($fields['step_discount']['enabled'])) {
-                    $benefits['spend_discount'] = [
+                    $benefits['step_discount'] = [
-                        'min_spend' => (float) ($fields['spend_discount']['min_spend'] ?? 0),
+                        'step_amount' => (float) ($fields['step_discount']['step_amount'] ?? 0),
-                        'discount_amount' => (float) ($fields['spend_discount']['discount_amount'] ?? 0),
+                        'discount_per_step' => (float) ($fields['step_discount']['discount_per_step'] ?? 0),
+                        'max_spend' => (float) ($fields['step_discount']['max_spend'] ?? 0),
                     ];
                 }
 

wp-content/plugins/bookstore-core/includes/Cli/Commands.php

@@ -449,10 +449,12 @@ class Commands
      * Sets (or replaces) one benefit on a tier. Benefit types with real
      * code behind them today: free_shipping_threshold (Shipping\
      * BSC_Free_Shipping, expects {"threshold": <number>}) and
-     * spend_discount (Membership\MemberDiscount, expects {"min_spend":
+     * step_discount (Membership\MemberDiscount, expects {"step_amount":
-     * <number>, "discount_amount": <number>}). Any other type is stored
+     * <number>, "discount_per_step": <number>, "max_spend": <number>} —
-     * but has no runtime effect until something reads it — see the
+     * e.g. step_amount=50/discount_per_step=5/max_spend=200 means $5 off
-     * class docblocks for why.
+     * per $50 spent, capped at $20 off). Any other type is stored but
+     * has no runtime effect until something reads it — see the class
+     * docblocks for why.
      *
      * ## OPTIONS
      *
@@ -467,7 +469,7 @@ class Commands
      *
      * ## EXAMPLES
      *
-     *     wp bookstore tier-set-benefit free_member spend_discount '{"min_spend":100,"discount_amount":10}'
+     *     wp bookstore tier-set-benefit free_member step_discount '{"step_amount":50,"discount_per_step":5,"max_spend":200}'
      *
      * @subcommand tier-set-benefit
      */

wp-content/plugins/bookstore-core/includes/Membership/MemberDiscount.php

@@ -5,14 +5,25 @@ namespace Bookstore\Core\Membership;
 defined('ABSPATH') || exit;
 
 /**
- * Design doc §07 extension: "$10 off orders $100+, members only." A flat
+ * Design doc §07 extension: a stepped, sitewide promo — $5 off per $50
- * per-cart-subtotal discount via WC_Cart::add_fee (a negative fee),
+ * spent, capping at $200 spend for a max $20 off (evolved from an
- * driven entirely by the current customer's `spend_discount` tier
+ * earlier flat "$10 off $100+, members only" version). Applied via
- * benefit — same shape as Shipping\BSC_Free_Shipping's threshold, just a
+ * WC_Cart::add_fee (a negative fee), driven entirely by the current
- * fee instead of a shipping rate. Business case: BooksRun charges a flat
+ * customer's `step_discount` tier benefit — same shape as
- * per-order shipping fee regardless of order size, so bundling a
+ * Shipping\BSC_Free_Shipping's threshold, just a fee instead of a
- * customer's purchases into one $100+ order rather than several smaller
+ * shipping rate. Business case: BooksRun charges a flat per-order
- * ones saves that fee outright — more than covering the $10 discount.
+ * shipping fee regardless of order size, so bundling a customer's
+ * purchases into one larger order rather than several smaller ones
+ * saves that fee outright — more than covering the discount.
+ *
+ * "Sitewide" isn't a separate concept from the member-tier system — the
+ * `guest` tier (the universal fallback for every non-member customer;
+ * see Membership\Tier::tier_for_user()) carries the same `step_discount`
+ * benefit as `free_member` by default, so every customer gets it unless
+ * an admin unchecks it on one tier or the other via the settings screen
+ * (WooCommerce > Settings > Membership Tiers) — e.g. unchecking it only
+ * on `guest` turns this into a members-only promo without touching any
+ * code.
  *
  * Runs on woocommerce_cart_calculate_fees, which fires well before
  * Order\CheckoutRecheck's hooks and bakes the fee into cart/order totals
@@ -30,16 +41,22 @@ class MemberDiscount
     public static function apply(\WC_Cart $cart): void
     {
         $user_id = get_current_user_id();
-        $config = Tier::benefit_config_for_user($user_id, 'spend_discount');
+        $config = Tier::benefit_config_for_user($user_id, 'step_discount');
-        if (empty($config['min_spend']) || empty($config['discount_amount'])) {
+        if (empty($config['step_amount']) || empty($config['discount_per_step']) || empty($config['max_spend'])) {
             return;
         }
 
+        $step_amount = (float) $config['step_amount'];
         $subtotal = (float) $cart->get_subtotal();
-        if ($subtotal < (float) $config['min_spend']) {
-            return;
-        }
 
-        $cart->add_fee('Member discount', -1 * (float) $config['discount_amount'], false);
+        $steps = min(
+            floor($subtotal / $step_amount),
+            floor((float) $config['max_spend'] / $step_amount)
+        );
+        $discount = $steps * (float) $config['discount_per_step'];
+
+        if ($discount > 0) {
+            $cart->add_fee('Member discount', -1 * $discount, false);
+        }
     }
 }

wp-content/plugins/bookstore-core/includes/Membership/Tier.php

@@ -205,12 +205,13 @@ class Tier
         if (!self::find_by_slug(self::GUEST_SLUG)) {
             self::create(self::GUEST_SLUG, 'Guest', 0, [
                 'free_shipping_threshold' => ['threshold' => 25.00],
+                'step_discount' => ['step_amount' => 50, 'discount_per_step' => 5, 'max_spend' => 200],
             ]);
         }
         if (!self::find_by_slug(self::FREE_MEMBER_SLUG)) {
             self::create(self::FREE_MEMBER_SLUG, 'Free Member', 10, [
                 'free_shipping_threshold' => ['threshold' => 15.00],
-                'spend_discount' => ['min_spend' => 100.00, 'discount_amount' => 10.00],
+                'step_discount' => ['step_amount' => 50, 'discount_per_step' => 5, 'max_spend' => 200],
             ]);
         }
     }

wp-content/plugins/bookstore-core/includes/Schema.php

@@ -174,5 +174,25 @@ class Schema
         }
 
         self::install();
+
+        // v3 -> v4: the flat "$10 off $100+" spend_discount benefit
+        // became a stepped, sitewide promo ($5 per $50 spent, capped at
+        // $200) — see Membership\MemberDiscount. A genuine product-
+        // default change, not a hypothetical admin customization worth
+        // preserving (pre-launch — see project memory on schema
+        // migrations), so this overwrites guest/free_member's benefits
+        // directly rather than merging. Post-launch, a change like this
+        // must target only the specific keys being replaced instead.
+        if ($current !== false && version_compare((string) $current, '4', '<')) {
+            $step_discount = ['step_amount' => 50, 'discount_per_step' => 5, 'max_spend' => 200];
+            Tier::update_benefits(Tier::GUEST_SLUG, [
+                'free_shipping_threshold' => ['threshold' => 25.00],
+                'step_discount' => $step_discount,
+            ]);
+            Tier::update_benefits(Tier::FREE_MEMBER_SLUG, [
+                'free_shipping_threshold' => ['threshold' => 15.00],
+                'step_discount' => $step_discount,
+            ]);
+        }
     }
 }

wp-content/plugins/bookstore-core/tests/Unit/Membership/MemberDiscountTest.php

@@ -8,11 +8,14 @@ use Brain\Monkey\Functions;
 use Mockery;
 
 /**
- * "$10 off orders $100+, members only" (design doc §07 extension). The
+ * The stepped, sitewide promo: $5 off per $50 spent, capped at $200
- * real Membership\Tier class runs unmocked — only $wpdb (underneath
+ * spend for a max $20 off (evolved from an earlier flat "$10 off $100+,
- * Tier's queries), get_current_user_id(), and a WC_Cart mock are
+ * members only" version — design doc §07 extension). "Sitewide" means
- * stubbed, so these tests exercise the actual threshold/amount lookup,
+ * both `guest` and `free_member` carry the same `step_discount` benefit
- * not just a canned discount value.
+ * by default, so a guest (user_id 0) getting the discount is the thing
+ * that specifically proves this isn't members-only anymore. The real
+ * Membership\Tier class runs unmocked — only $wpdb (underneath Tier's
+ * queries), get_current_user_id(), and a WC_Cart mock are stubbed.
  */
 class MemberDiscountTest extends TestCase
 {
@@ -23,40 +26,52 @@ class MemberDiscountTest extends TestCase
         parent::tearDown();
     }
 
-    public function test_guest_gets_no_discount(): void
+    /**
-    {
+     * @dataProvider subtotalCases
-        Functions\when('get_current_user_id')->justReturn(0);
+     */
-        // Guest tier has no spend_discount benefit configured.
+    public function test_member_gets_the_stepped_discount(float $subtotal, float $expected_discount): void
-        $this->stub_wpdb_anonymous(['free_shipping_threshold' => ['threshold' => 25.00]]);
-
-        $cart = Mockery::mock(\WC_Cart::class);
-        $cart->shouldReceive('get_subtotal')->andReturn('500.00');
-        $cart->shouldNotReceive('add_fee');
-
-        MemberDiscount::apply($cart);
-    }
-
-    public function test_member_below_min_spend_gets_no_discount(): void
     {
         Functions\when('get_current_user_id')->justReturn(7);
         $this->stub_wpdb_with_member_lookup(5, [
             'free_shipping_threshold' => ['threshold' => 15.00],
-            'spend_discount' => ['min_spend' => 100.00, 'discount_amount' => 10.00],
+            'step_discount' => ['step_amount' => 50, 'discount_per_step' => 5, 'max_spend' => 200],
         ]);
 
         $cart = Mockery::mock(\WC_Cart::class);
-        $cart->shouldReceive('get_subtotal')->andReturn('80.00');
+        $cart->shouldReceive('get_subtotal')->andReturn((string) $subtotal);
+
+        if ($expected_discount > 0) {
+            $cart->shouldReceive('add_fee')->once()->with('Member discount', -1 * $expected_discount, false);
+        } else {
             $cart->shouldNotReceive('add_fee');
+        }
 
         MemberDiscount::apply($cart);
     }
 
-    public function test_member_at_min_spend_gets_the_discount(): void
+    public static function subtotalCases(): array
     {
-        Functions\when('get_current_user_id')->justReturn(7);
+        return [
-        $this->stub_wpdb_with_member_lookup(5, [
+            'nothing in cart' => [0.00, 0.00],
-            'free_shipping_threshold' => ['threshold' => 15.00],
+            'below the first step' => [30.00, 0.00],
-            'spend_discount' => ['min_spend' => 100.00, 'discount_amount' => 10.00],
+            'exactly the first step' => [50.00, 5.00],
+            'just under the second step' => [99.99, 5.00],
+            'exactly the second step' => [100.00, 10.00],
+            'exactly the third step' => [150.00, 15.00],
+            'just under the cap' => [199.99, 15.00],
+            'exactly at the cap' => [200.00, 20.00],
+            'above the cap stays capped' => [250.00, 20.00],
+        ];
+    }
+
+    public function test_guest_gets_the_discount_too_sitewide_by_default(): void
+    {
+        Functions\when('get_current_user_id')->justReturn(0);
+        // guest tier carries the same step_discount benefit as
+        // free_member by default -- this is what makes it sitewide.
+        $this->stub_wpdb_anonymous([
+            'free_shipping_threshold' => ['threshold' => 25.00],
+            'step_discount' => ['step_amount' => 50, 'discount_per_step' => 5, 'max_spend' => 200],
         ]);
 
         $cart = Mockery::mock(\WC_Cart::class);
@@ -66,16 +81,19 @@ class MemberDiscountTest extends TestCase
         MemberDiscount::apply($cart);
     }
 
-    public function test_member_above_min_spend_gets_the_discount(): void
+    public function test_guest_gets_nothing_when_admin_disables_it_on_the_guest_tier(): void
     {
-        Functions\when('get_current_user_id')->justReturn(7);
+        Functions\when('get_current_user_id')->justReturn(0);
-        $this->stub_wpdb_with_member_lookup(5, [
+        // Admin unchecked step_discount on the guest row via the
-            'spend_discount' => ['min_spend' => 100.00, 'discount_amount' => 10.00],
+        // settings screen -- members-only mode, proven by the absence
+        // of the benefit key here (not a hardcoded "guest excluded").
+        $this->stub_wpdb_anonymous([
+            'free_shipping_threshold' => ['threshold' => 25.00],
         ]);
 
         $cart = Mockery::mock(\WC_Cart::class);
-        $cart->shouldReceive('get_subtotal')->andReturn('142.50');
+        $cart->shouldReceive('get_subtotal')->andReturn('250.00');
-        $cart->shouldReceive('add_fee')->once()->with('Member discount', -10.00, false);
+        $cart->shouldNotReceive('add_fee');
 
         MemberDiscount::apply($cart);
     }