Extend filtered_gems to do filtering on install conditions as well

lib/gel/environment.rb

@@ -435,7 +435,12 @@ def self.find_executable(exe, gem_name = nil, gem_version = nil)
 
   def self.filtered_gems(gems = self.gemfile.gems)
     platforms = GEMFILE_PLATFORMS.map(&:to_s)
-    gems = gems.reject { |g| g[2][:platforms] && (Array(g[2][:platforms]).map(&:to_s) & platforms).empty? }
+    gems = gems.reject do |_, _, options|
+      platform_options = Array(options[:platforms]).map(&:to_s)
+
+      next true if platform_options.any? && (platform_options & platforms).empty?
+      next true unless options.fetch(:install_if, true)
+    end
     gems
   end
 

test/lock_activate_test.rb

@@ -90,15 +90,21 @@ def test_activate_lockfile_with_path
 
   def test_ignore_gems_excluded_by_gemfile
     gemfile_content = <<GEMFILE
-gem "rack"
+gem "rack", install_if: true
 gem "rack-test", platforms: :rbx
+gem "hoe", install_if: false
+install_if ->{ false } do
+  gem "atomic"
+end
 GEMFILE
 
     lockfile = Tempfile.new("")
     lockfile.write(<<LOCKFILE)
 GEM
   remote: https://rubygems.org/
   specs:
+    atomic (1.1.16)
+    hoe (3.0.0)
     rack (2.0.3)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -109,7 +115,7 @@ def test_ignore_gems_excluded_by_gemfile
 LOCKFILE
     lockfile.close
 
-    with_fixture_gems_installed(["rack-test-0.6.3.gem", "rack-2.0.3.gem", "hoe-3.0.0.gem"]) do |store|
+    with_fixture_gems_installed(["rack-test-0.6.3.gem", "rack-2.0.3.gem", "hoe-3.0.0.gem", "atomic-1.1.16.gem"]) do |store|
       output = subprocess_output(<<-'END', store: store, lock_path: lockfile.path, gemfile_content: gemfile_content)
         loader = Gel::LockLoader.new(lock_path, Gel::GemfileParser.parse(gemfile_content))
         loader.activate(Gel::Environment, store)