Auto merge of #6517 - agrim123:agr-bundler-add-skip-install, r=colby-swandale

Add --skip-install flag to bundle add

Usage
```bash
bundle add rack --skip-install
```
This flag would not install the gem, only add it to the gemfile.

Closes #6511

(cherry picked from commit c793c38a55559677573d28d4bfadd811e8508b48)

4 files changed, 20 insertions, 4 deletions

diff --git a/lib/bundler/cli.rb b/lib/bundler/cli.rb
index a0362f35d0..bd4f360546 100644
--- a/lib/bundler/cli.rb
+++ b/lib/bundler/cli.rb
@@ -331,7 +331,8 @@ module Bundler
     method_option "version", :aliases => "-v", :type => :string
     method_option "group", :aliases => "-g", :type => :string
     method_option "source", :aliases => "-s", :type => :string
-
+    method_option "skip-install", :type => :boolean, :banner =>
+      "Adds gem to the Gemfile but does not install it"
     def add(gem_name)
       require "bundler/cli/add"
       Add.new(options.dup, gem_name).run
diff --git a/lib/bundler/cli/add.rb b/lib/bundler/cli/add.rb
index 1fcbd22f28..e1a662161e 100644
--- a/lib/bundler/cli/add.rb
+++ b/lib/bundler/cli/add.rb
@@ -19,7 +19,7 @@ module Bundler
       dependency = Bundler::Dependency.new(@gem_name, version, @options)
 
       Injector.inject([dependency], :conservative_versioning => @options[:version].nil?) # Perform conservative versioning only when version is not specified
-      Installer.install(Bundler.root, Bundler.definition)
+      Installer.install(Bundler.root, Bundler.definition) unless @options["skip-install"]
     end
   end
 end
diff --git a/man/bundle-add.ronn b/man/bundle-add.ronn
index f0f9b54d8f..91eb1d7188 100644
--- a/man/bundle-add.ronn
+++ b/man/bundle-add.ronn
@@ -3,10 +3,10 @@ bundle-add(1) -- Add gem to the Gemfile and run bundle install
 
 ## SYNOPSIS
 
-`bundle add` <GEM_NAME> [--group=GROUP] [--version=VERSION] [--source=SOURCE]
+`bundle add` <GEM_NAME> [--group=GROUP] [--version=VERSION] [--source=SOURCE] [--skip-install]
 
 ## DESCRIPTION
-Adds the named gem to the Gemfile and run `bundle install`.
+Adds the named gem to the Gemfile and run `bundle install`. `bundle install` can be avoided by using the flag `--skip-install`.
 
 Example:
 
@@ -16,6 +16,8 @@ bundle add rails --version "< 3.0, > 1.1"
 
 bundle add rails --version "~> 5.0.0" --source "https://gems.example.com" --group "development"
 
+bundle add rails --skip-install
+
 bundle add rails --group "development, test"
 
 ## OPTIONS
@@ -27,3 +29,6 @@ bundle add rails --group "development, test"
 
 * `--source`, , `-s`:
   Specify the source for the added gem.
+
+* `--skip-install`:
+  Adds the gem to the Gemfile but does not install it.
diff --git a/spec/commands/add_spec.rb b/spec/commands/add_spec.rb
index 799c8a1b93..fb3bd9928d 100644
--- a/spec/commands/add_spec.rb
+++ b/spec/commands/add_spec.rb
@@ -75,11 +75,21 @@ RSpec.describe "bundle add" do
   describe "with --source" do
     it "adds dependency with specified source" do
       bundle "add 'foo' --source='file://#{gem_repo2}'"
+
       expect(bundled_app("Gemfile").read).to match(%r{gem "foo", "~> 2.0", :source => "file:\/\/#{gem_repo2}"})
       expect(the_bundle).to include_gems "foo 2.0"
     end
   end
 
+  describe "with --skip-install" do
+    it "adds gem to Gemfile but is not installed" do
+      bundle "add foo --skip-install --version=2.0"
+
+      expect(bundled_app("Gemfile").read).to match(/gem "foo", "= 2.0"/)
+      expect(the_bundle).to_not include_gems "foo 2.0"
+    end
+  end
+
   it "using combination of short form options works like long form" do
     bundle "add 'foo' -s='file://#{gem_repo2}' -g='development' -v='~>1.0'"
     expect(bundled_app("Gemfile").read).to include %(gem "foo", "~> 1.0", :group => :development, :source => "file://#{gem_repo2}")