From b20de1905ccf247c045bcc8a912747857609da11 Mon Sep 17 00:00:00 2001
From: Anton Davydov <antondavydov.o@gmail.com>
Date: Tue, 30 Apr 2019 02:40:01 +0300
Subject: [PATCH] Proof of concept idea injection dependencies by specific
 pattern

---
 lib/dry/auto_inject/builder.rb        | 11 +++++++++
 spec/integration/allow_inject_spec.rb | 34 +++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 spec/integration/allow_inject_spec.rb

diff --git a/lib/dry/auto_inject/builder.rb b/lib/dry/auto_inject/builder.rb
index 97e8cec..e256524 100644
--- a/lib/dry/auto_inject/builder.rb
+++ b/lib/dry/auto_inject/builder.rb
@@ -15,10 +15,17 @@ class Builder < BasicObject
       def initialize(container, options = {})
         @container = container
         @strategies = options.fetch(:strategies) { Strategies }
+        @pattern = options.fetch(:pattern) { nil }
+      end
+
+      def allow(pattern)
+        AutoInject::Builder.new(@container, pattern: pattern, strategies: @strategies)
       end
 
       # @api public
       def [](*dependency_names)
+        raise unless match_by_pattern?(dependency_names)
+
         default[*dependency_names]
       end
 
@@ -28,6 +35,10 @@ def respond_to?(name, include_private = false)
 
       private
 
+      def match_by_pattern?(dependency_names)
+        @pattern.nil? || dependency_names.all? { |dependency| dependency.match(@pattern) }
+      end
+
       def method_missing(name, *args, &block)
         if strategies.key?(name)
           Injector.new(container, strategies[name], builder: self)
diff --git a/spec/integration/allow_inject_spec.rb b/spec/integration/allow_inject_spec.rb
new file mode 100644
index 0000000..fa5e60a
--- /dev/null
+++ b/spec/integration/allow_inject_spec.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+RSpec.describe "allow condition" do
+  describe "allow" do
+    before do
+      module Test
+        AutoInject = Dry::AutoInject({one: 1, two: 2})
+        OnlyOneInject = AutoInject.allow(/one/)
+      end
+    end
+
+    subject(:instance) { including_class.new }
+
+    context 'when user injects allowed keys' do
+      let(:including_class) do
+        Class.new do
+          include Test::OnlyOneInject[:one]
+        end
+      end
+
+      it { expect(instance.one).to eq 1 }
+    end
+
+    context 'when user injects all keys' do
+      let(:including_class) do
+        Class.new do
+          include Test::OnlyOneInject[:one, :two]
+        end
+      end
+
+      it { expect { instance }.to raise_error }
+    end
+  end
+end