From 7e8c86d16bc6a51062e10a94b46f2ea63d89a73e Mon Sep 17 00:00:00 2001
From: Javier Aranda <aranda@hey.com>
Date: Thu, 7 Dec 2023 12:58:47 +0100
Subject: [PATCH] Implements compound variants

---
 lib/class_variants/instance.rb | 18 +++++++++++++-----
 readme.md                      | 25 ++++++++++++++++++++++++-
 test/class_variants_test.rb    | 16 ++++++++++++++++
 3 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/lib/class_variants/instance.rb b/lib/class_variants/instance.rb
index c60d25e..bca5f97 100644
--- a/lib/class_variants/instance.rb
+++ b/lib/class_variants/instance.rb
@@ -3,9 +3,10 @@ class ClassVariants::Instance
   attr_reader :variants
   attr_reader :defaults
 
-  def initialize(classes = "", variants: {}, defaults: {})
+  def initialize(classes = "", variants: {}, compoundVariants: [], defaults: {})
     @classes = classes
     @variants = expand_boolean_variants(variants)
+    @compoundVariants = compoundVariants
     @defaults = defaults
   end
 
@@ -14,11 +15,18 @@ def render(**overrides)
     result = [@classes]
 
     # Then merge the passed in overrides on top of the defaults
-    @defaults.merge(overrides)
-      .each do |variant_type, variant|
-        # dig the classes out and add them to the result
-        result << @variants.dig(variant_type, variant)
+    selected = @defaults.merge(overrides)
+
+    selected.each do |variant_type, variant|
+      # dig the classes out and add them to the result
+      result << @variants.dig(variant_type, variant)
+    end
+
+    @compoundVariants.each do |compound_variant|
+      if (compound_variant.keys - [:class]).all? { |key| selected[key] == compound_variant[key] }
+        result << compound_variant[:class]
       end
+    end
 
     # Compact out any nil values we may have dug up
     result.compact!
diff --git a/readme.md b/readme.md
index 1a160aa..0c7a8bc 100644
--- a/readme.md
+++ b/readme.md
@@ -31,10 +31,11 @@ $ gem install class_variants
 
 ## Usage
 
-We create an object from the class or helper where we define the configuration using three arguments:
+We create an object from the class or helper where we define the configuration using four arguments:
 
 1. The default classes that should be applied to each variant
 1. The `variants` keyword argument where we declare the variants with their option and classes
+1. The `compoundVariants` keyword argument where we declare the compound variants with their conditions and classes
 1. The `defaults` keyword argument (optional) where we declare the default value for each variant.
 
 ## Example
@@ -77,6 +78,28 @@ button_classes.render
 button_classes.render(color: :red, size: :xl, icon: true)
 ```
 
+### Compound Variants
+
+```ruby
+button_classes = ClassVariants.build(
+  "inline-flex items-center rounded",
+  variants: {
+    color: {
+      red:  "bg-red-600",
+      blue: "bg-blue-600",
+    },
+    border: "border"
+  },
+  compoundVariants: [
+    { color: :red,  border: true, class: "border-red-800"  },
+    { color: :blue, border: true, class: "border-blue-800" }
+  ]
+)
+
+button_classes.render(color: :red) # => "inline-flex items-center rounded bg-red-600"
+button_classes.render(color: :red, border: true) # => "inline-flex items-center rounded bg-red-600 border border-red-600"
+```
+
 ## Use with Rails
 
 ```ruby
diff --git a/test/class_variants_test.rb b/test/class_variants_test.rb
index 4fcf61d..c801df8 100644
--- a/test/class_variants_test.rb
+++ b/test/class_variants_test.rb
@@ -13,9 +13,14 @@ def setup
           red: "text-red",
           green: "text-green"
         },
+        ring: "focus:ring-2",
         visible: "inline-block",
         "!visible": "hidden"
       },
+      compoundVariants: [
+        { ring: true, color: :red, class: "focus:ring-red-600" },
+        { ring: true, color: :green, class: "focus:ring-green-600" }
+      ],
       defaults: {
         size: :md
       }
@@ -38,4 +43,15 @@ def test_boolean_variants
     assert_equal "rounded border text-md inline-block", @cv.render(visible: true)
     assert_equal "rounded border text-md hidden", @cv.render(visible: false)
   end
+
+  def test_compound_variants
+    assert_equal(
+      "rounded border text-md focus:ring-2 text-red focus:ring-red-600",
+      @cv.render(ring: true, color: :red)
+    )
+    assert_equal(
+      "rounded border text-md focus:ring-2 text-green focus:ring-green-600",
+      @cv.render(ring: true, color: :green)
+    )
+  end
 end