Resolver: treat dependencies with prerelease versions as slightly constrained

3 files changed, 24 insertions, 1 deletions

diff --git a/lib/bundler/resolver.rb b/lib/bundler/resolver.rb
index 8a3afa3418..d7911c1de2 100644
--- a/lib/bundler/resolver.rb
+++ b/lib/bundler/resolver.rb
@@ -249,7 +249,8 @@ module Bundler
           if all <= 1
             all - 1_000_000
           else
-            search = search_for(dependency).size
+            search = search_for(dependency)
+            search = @prerelease_specified[dependency.name] ? search.count : search.count {|s| !s.version.prerelease? }
             search - all
           end
         end
diff --git a/spec/resolver/basic_spec.rb b/spec/resolver/basic_spec.rb
index 568958ae00..c829243a9f 100644
--- a/spec/resolver/basic_spec.rb
+++ b/spec/resolver/basic_spec.rb
@@ -42,6 +42,13 @@ RSpec.describe "Resolving" do
     should_resolve_as %w[a-1.0.0 b-2.0.0 c-1.0.0 d-1.0.0]
   end
 
+  it "prefers non-prerelease resolutions in sort order" do
+    @index = optional_prereleases_index
+    dep "a"
+    dep "b"
+    should_resolve_as %w[a-1.0.0 b-1.5.0]
+  end
+
   it "resolves a index with root level conflict on child" do
     @index = a_index_with_root_conflict_on_child
     dep "i18n", "~> 0.4"
diff --git a/spec/support/indexes.rb b/spec/support/indexes.rb
index 05605195b1..c56d6145a7 100644
--- a/spec/support/indexes.rb
+++ b/spec/support/indexes.rb
@@ -401,5 +401,20 @@ module Spec
         gem("d", %w[1.0.0 2.0.0])
       end
     end
+
+    def optional_prereleases_index
+      build_index do
+        gem("a", %w[1.0.0])
+
+        gem("a", "2.0.0") do
+          dep "b", ">= 2.0.0.pre"
+        end
+
+        gem("b", %w[0.9.0 1.5.0 2.0.0.pre])
+
+        # --- Pre-release support
+        gem "rubygems\0", ["1.3.2"]
+      end
+    end
   end
 end