Respect explicit source: option on gem entries

lib/gel/catalog.rb

@@ -86,6 +86,10 @@ def to_s
     @uri.to_s
   end
 
+  def match?(uri)
+    @uri == normalize_uri(uri)
+  end
+
   private
 
   def normalize_uri(uri)

lib/gel/catalog_set.rb

@@ -9,8 +9,9 @@ def gem_version
     end
   end
 
-  def initialize(catalogs)
+  def initialize(catalogs, gemfile)
     @catalogs = catalogs
+    @gemfile = gemfile
 
     @cached_specs = Hash.new { |h, k| h[k] = {} }
     @specs_by_package_version = {}
@@ -68,8 +69,19 @@ def platform_for(package, version)
   def fetch_package_info(package)
     return if @specs_by_package_version.key?(package.name)
 
+    catalogs = @catalogs
+
+    if gem_entry = @gemfile.gems.assoc(package.name)
+      if specified_sources = gem_entry[2][:source]
+        catalogs = catalogs.select do |catalog|
+          catalog.is_a?(Gel::Catalog) &&
+            Array(specified_sources).any? { |s| catalog.match?(s) }
+        end
+      end
+    end
+
     specs = []
-    @catalogs.each do |catalog|
+    catalogs.each do |catalog|
       if catalog.nil?
         break unless specs.empty?
         next

lib/gel/environment.rb

@@ -165,9 +165,14 @@ def self.solve_for_gemfile(store: store(), output: nil, gemfile: Gel::Environmen
     require_relative "catalog"
     all_sources = (gemfile.sources | gemfile.gems.flat_map { |_, _, o| o[:source] }).compact
     local_source = all_sources.delete(:local)
-    server_gems = gemfile.gems.select { |_, _, o| !o[:path] && !o[:git] }.map(&:first)
+    server_gems = gemfile.gems.select { |_, _, o| !o[:path] && !o[:git] }
     catalog_pool = Gel::WorkPool.new(8, name: "gel-catalog")
-    server_catalogs = all_sources.map { |s| Gel::Catalog.new(s, initial_gems: server_gems, work_pool: catalog_pool, **catalog_options) }
+    server_catalogs = all_sources.map do |s|
+      source_gems = server_gems.
+        select { |_, _, o| Array(o[:source]).include?(s) || o[:source].nil? }.
+        map(&:first)
+      Gel::Catalog.new(s, initial_gems: source_gems, work_pool: catalog_pool, **catalog_options)
+    end
 
     require_relative "store_catalog"
     store = store.inner if store.is_a?(Gel::LockedStore)
@@ -239,7 +244,7 @@ def self.solve_for_gemfile(store: store(), output: nil, gemfile: Gel::Environmen
     end
 
     require_relative "catalog_set"
-    catalog_set = Gel::CatalogSet.new(catalogs)
+    catalog_set = Gel::CatalogSet.new(catalogs, gemfile)
 
     if solve
       require_relative "pub_grub/solver"

test/resolve_test.rb

@@ -111,6 +111,57 @@ def test_respects_range_specifier
 LOCKFILE
   end
 
+  def test_respects_explicit_source
+    gemfile = <<GEMFILE
+source "https://rubygems.org"
+
+gem "rack", source: "https://other.org"
+GEMFILE
+
+    stub_request(:get, "https://index.rubygems.org/versions").
+      to_return(body: <<VERSIONS)
+created_at: 2017-03-27T04:38:13+00:00
+---
+rack 0.1.0,2.0.3 xxx
+rack 0.1.1 yyy
+VERSIONS
+
+    stub_request(:get, "https://index.rubygems.org/info/rack").
+      to_return(body: <<INFO)
+---
+0.1.0 |checksum:zzz
+2.0.3 |checksum:zzz
+0.1.1 |checksum:zzz
+INFO
+
+    stub_request(:get, "https://other.org/versions").
+      to_return(body: <<VERSIONS)
+created_at: 2017-03-27T04:38:13+00:00
+---
+rack 0.5.0 qqq
+VERSIONS
+
+    stub_request(:get, "https://other.org/info/rack").
+      to_return(body: <<INFO)
+---
+0.5.0 |checksum:ccc
+INFO
+
+    assert_equal <<LOCKFILE, lockfile_for_gemfile(gemfile, platforms: "ruby")
+GEM
+  remote: https://rubygems.org/
+  remote: https://other.org/
+  specs:
+    rack (0.5.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  rack!
+LOCKFILE
+  end
+
   def test_dependencies_are_followed_and_recorded
     gemfile = <<GEMFILE
 source "https://gem-mimer.org"