Hooks implementation

5 files changed, 69 insertions, 5 deletions

diff --git a/lib/bundler/cli/install.rb b/lib/bundler/cli/install.rb
index 5c7b8c5b0b..f95b2779c2 100644
--- a/lib/bundler/cli/install.rb
+++ b/lib/bundler/cli/install.rb
@@ -68,6 +68,8 @@ module Bundler
       definition = Bundler.definition
       definition.validate_ruby!
 
+      Plugin.hook("before-install-all", definition.dependencies)
+
       installer = Installer.install(Bundler.root, definition, options)
       Bundler.load.cache if Bundler.app_cache.exist? && !options["no-cache"] && !Bundler.settings[:frozen]
 
diff --git a/lib/bundler/plugin.rb b/lib/bundler/plugin.rb
index cd3843fc0d..e55f0fcf1b 100644
--- a/lib/bundler/plugin.rb
+++ b/lib/bundler/plugin.rb
@@ -18,6 +18,8 @@ module Bundler
 
     @commands = {}
     @sources = {}
+    @hooks = {}
+    @loaded = []
 
     # Installs a new plugin by the given name
     #
@@ -137,6 +139,19 @@ module Bundler
       src.new(locked_opts.merge("uri" => locked_opts["remote"]))
     end
 
+    def add_hook(event, &block)
+      (@hooks[event.to_s] ||= []) << block
+    end
+
+    def hook(event, *args)
+      plugins = index.hook_plugins(event)
+      return unless plugins
+
+      (plugins - @loaded).each {|name| load_plugin(name) }
+
+      @hooks[event].each {|blk| blk.call(*args) }
+    end
+
     # currently only intended for specs
     #
     # @return [String, nil] installed path
@@ -190,9 +205,11 @@ module Bundler
     def register_plugin(name, spec, optional_plugin = false)
       commands = @commands
       sources = @sources
+      hooks = @hooks
 
       @commands = {}
       @sources = {}
+      @hooks = {}
 
       load_paths = spec.load_paths
       add_to_load_path(load_paths)
@@ -208,12 +225,14 @@ module Bundler
         Bundler.rm_rf(path)
         false
       else
-        index.register_plugin name, path.to_s, load_paths, @commands.keys, @sources.keys
+        index.register_plugin name, path.to_s, load_paths, @commands.keys,
+          @sources.keys, @hooks.keys
         true
       end
     ensure
       @commands = commands
       @sources = sources
+      @hooks = hooks
     end
 
     # Executes the plugins.rb file
@@ -228,6 +247,8 @@ module Bundler
       add_to_load_path(index.load_paths(name))
 
       load path.join(PLUGIN_FILE_NAME)
+
+      @loaded << name
     rescue => e
       Bundler.ui.error "Failed loading plugin #{name}: #{e.message}"
       raise
diff --git a/lib/bundler/plugin/api.rb b/lib/bundler/plugin/api.rb
index 9ff4b7385b..5bd8792e55 100644
--- a/lib/bundler/plugin/api.rb
+++ b/lib/bundler/plugin/api.rb
@@ -44,6 +44,10 @@ module Bundler
         Plugin.add_source source, cls
       end
 
+      def self.hook(event, &block)
+        Plugin.add_hook(event, &block)
+      end
+
       # The cache dir to be used by the plugins for storage
       #
       # @return [Pathname] path of the cache dir
diff --git a/lib/bundler/plugin/index.rb b/lib/bundler/plugin/index.rb
index 918b3a4392..455fb7b775 100644
--- a/lib/bundler/plugin/index.rb
+++ b/lib/bundler/plugin/index.rb
@@ -24,6 +24,7 @@ module Bundler
         @plugin_paths = {}
         @commands = {}
         @sources = {}
+        @hooks = {}
         @load_paths = {}
 
         load_index(global_index_file, true)
@@ -39,7 +40,7 @@ module Bundler
       # @param [Array<String>] load_paths for the plugin
       # @param [Array<String>] commands that are handled by the plugin
       # @param [Array<String>] sources that are handled by the plugin
-      def register_plugin(name, path, load_paths, commands, sources)
+      def register_plugin(name, path, load_paths, commands, sources, hooks)
         old_commands = @commands.dup
 
         common = commands & @commands.keys
@@ -50,6 +51,8 @@ module Bundler
         raise SourceConflict.new(name, common) unless common.empty?
         sources.each {|k| @sources[k] = name }
 
+        hooks.each {|e| (@hooks[e] ||= []) << name }
+
         @plugin_paths[name] = path
         @load_paths[name] = load_paths
         save_index
@@ -98,6 +101,10 @@ module Bundler
         @sources[name]
       end
 
+      def hook_plugins(event)
+        @hooks[event]
+      end
+
     private
 
       # Reads the index file from the directory and initializes the instance
@@ -119,6 +126,7 @@ module Bundler
           @load_paths.merge!(index["load_paths"])
           @commands.merge!(index["commands"])
           @sources.merge!(index["sources"]) unless global
+          @hooks.merge!(index["hooks"])
         end
       end
 
@@ -128,9 +136,10 @@ module Bundler
       def save_index
         index = {
           "plugin_paths" => @plugin_paths,
-          "load_paths" => @load_paths,
-          "commands" => @commands,
-          "sources" => @sources,
+          "load_paths"   => @load_paths,
+          "commands"     => @commands,
+          "sources"      => @sources,
+          "hooks"        => @hooks,
         }
 
         require "bundler/yaml_serializer"
diff --git a/spec/plugins/hook_spec.rb b/spec/plugins/hook_spec.rb
new file mode 100644
index 0000000000..3622d2a6e9
--- /dev/null
+++ b/spec/plugins/hook_spec.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+require "spec_helper"
+
+describe "hook plugins", :focused do
+  before do
+    build_repo2 do
+      build_plugin "before-install-plugin" do |s|
+        s.write "plugins.rb", <<-RUBY
+          Bundler::Plugin::API.hook "before-install-all" do |deps|
+            puts "gems to be installed \#{deps.map(&:name).join(", ")}"
+          end
+        RUBY
+      end
+    end
+
+    bundle "plugin install before-install-plugin --source file://#{gem_repo2}"
+  end
+
+  it "runs after a rubygem is installed" do
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      gem "yaml_spec"
+      gem "rake"
+    G
+
+    expect(out).to include "gems to be installed yaml_spec, rake"
+  end
+end