From 35f22a4ad0e4fec86f9ac7a5ff63d62c575d294d Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 28 Oct 2020 13:01:43 +0100
Subject: [PATCH 01/13] Raise descriptive error when update is not possible

Currently we are actually raising a `can't modify frozen NilClass` error
because we attempt to `instance_variable_set` on `nil`, as we try to
find `dependency` in the Gemfile.

This is a small step towards figuring out what dependency is blocking
for an update.
---
 bundler/helpers/lib/functions/force_updater.rb | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/bundler/helpers/lib/functions/force_updater.rb b/bundler/helpers/lib/functions/force_updater.rb
index 6e262fc9fa..34bf3e2bba 100644
--- a/bundler/helpers/lib/functions/force_updater.rb
+++ b/bundler/helpers/lib/functions/force_updater.rb
@@ -1,5 +1,7 @@
 module Functions
   class ForceUpdater
+    class TransitiveDependencyError < StandardError; end
+
     def initialize(dependency_name:, target_version:, gemfile_name:,
                    lockfile_name:, update_multiple_dependencies:)
       @dependency_name = dependency_name
@@ -113,12 +115,15 @@ def build_definition(other_updates:)
 
       # Set the requirement for the gem we're forcing an update of
       new_req = Gem::Requirement.create("= #{target_version}")
-      definition.dependencies.
-        find { |d| d.name == dependency_name }.
-        tap do |dep|
-          dep.instance_variable_set(:@requirement, new_req)
-          dep.source = nil if dep.source.is_a?(Bundler::Source::Git)
-        end
+      dep = definition.dependencies.
+            find { |d| d.name == dependency_name }
+
+      # If the dependency is not found in the Gemfile it means this is a
+      # transitive dependency that we can't force update.
+      raise TransitiveDependencyError unless dep
+
+      dep.instance_variable_set(:@requirement, new_req)
+      dep.source = nil if dep.source.is_a?(Bundler::Source::Git)
 
       definition
     end

From 01499e82229f7472334911850d388553c989c6f6 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Mon, 2 Nov 2020 16:48:37 +0100
Subject: [PATCH 02/13] [SPIKE] explain why a bundler update was blocked

This returns a message from ForceUpdater that explains why a certain
update was not possible, by traversing the dependency tree and finding
all parent dependencies that are not satisfied by the target version.

Few things to improve:
- The message is now formatted in the native helper, I would prefer to
return raw data from there, and leave any formatting to whatever drives
dependabot.
- Because we currently depend on the native helper returning an error,
it is hard to pass data from the native function to dependabot-core.
- We need to call `latest_version_resolvable_with_full_unlock?` in order
to hit the error that sets this new message. I'd prefer to be able to
just call a method on the UpdateChecker instead.
- I dislike having to string compare against the native errors `error_type`, it
would be nice to have more granular errors that we can return from
there.
---
 .../helpers/lib/functions/force_updater.rb    | 27 ++++++++++++++++---
 .../lib/dependabot/bundler/update_checker.rb  |  7 ++++-
 .../dependabot/bundler/update_checker_spec.rb |  9 +++++++
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/bundler/helpers/lib/functions/force_updater.rb b/bundler/helpers/lib/functions/force_updater.rb
index 34bf3e2bba..90e75efc33 100644
--- a/bundler/helpers/lib/functions/force_updater.rb
+++ b/bundler/helpers/lib/functions/force_updater.rb
@@ -26,11 +26,11 @@ def run
         definition.resolve_remotely!
         specs = definition.resolve
         updates = [{ name: dependency_name }] +
-          other_updates.map { |dep| { name: dep.name } }
+                  other_updates.map { |dep| { name: dep.name } }
         specs = specs.map do |dep|
           {
             name: dep.name,
-            version: dep.version,
+            version: dep.version
           }
         end
         [updates, specs]
@@ -56,7 +56,7 @@ def run
     attr_reader :dependency_name, :target_version, :gemfile_name,
                 :lockfile_name, :credentials,
                 :update_multiple_dependencies
-    alias :update_multiple_dependencies? :update_multiple_dependencies
+    alias update_multiple_dependencies? update_multiple_dependencies
 
     def new_dependencies_to_unlock_from(error:, already_unlocked:)
       potentials_deps =
@@ -120,7 +120,7 @@ def build_definition(other_updates:)
 
       # If the dependency is not found in the Gemfile it means this is a
       # transitive dependency that we can't force update.
-      raise TransitiveDependencyError unless dep
+      raise TransitiveDependencyError, locked_by_parent_msg unless dep
 
       dep.instance_variable_set(:@requirement, new_req)
       dep.source = nil if dep.source.is_a?(Bundler::Source::Git)
@@ -153,6 +153,25 @@ def subdependencies
       all_deps - top_level
     end
 
+    def locked_by_parent_msg
+      version = Gem::Version.new(target_version)
+      specs = Bundler::LockfileParser.new(lockfile).specs.filter do |spec|
+        spec.dependencies.any? do |sub_dep|
+          sub_dep.name == dependency_name &&
+            !sub_dep.requirement.satisfied_by?(version)
+        end
+      end
+
+      locking = specs.map do |spec|
+        req = spec.dependencies.find { |bd| bd.name == dependency_name }
+        "#{spec.name} (#{spec.version}) which requires #{dependency_name} "\
+        "#{req.requirement}"
+      end
+
+      "#{dependency_name} cannot be updated to #{target_version} because it "\
+        "is locked by #{locking.join(', ')}"
+    end
+
     def unlock_gem(definition:, gem_name:)
       dep = definition.dependencies.find { |d| d.name == gem_name }
       version = definition.locked_gems.specs.
diff --git a/bundler/lib/dependabot/bundler/update_checker.rb b/bundler/lib/dependabot/bundler/update_checker.rb
index a925abc1c2..80cb6be2fd 100644
--- a/bundler/lib/dependabot/bundler/update_checker.rb
+++ b/bundler/lib/dependabot/bundler/update_checker.rb
@@ -107,6 +107,8 @@ def requirements_update_strategy
         dependency.version.nil? ? :bump_versions_if_necessary : :bump_versions
       end
 
+      attr_reader :blocked_by_parent_msg
+
       private
 
       def latest_version_resolvable_with_full_unlock?
@@ -157,7 +159,10 @@ def resolvable?(version)
               update_multiple_dependencies: false
             ).updated_dependencies
             true
-          rescue Dependabot::DependencyFileNotResolvable
+          rescue Dependabot::DependencyFileNotResolvable => e
+            if e.error_class.end_with?("TransitiveDependencyError")
+              @blocked_by_parent_msg = e.msg
+            end
             false
           end
       end
diff --git a/bundler/spec/dependabot/bundler/update_checker_spec.rb b/bundler/spec/dependabot/bundler/update_checker_spec.rb
index 4df583f69f..41db9857bd 100644
--- a/bundler/spec/dependabot/bundler/update_checker_spec.rb
+++ b/bundler/spec/dependabot/bundler/update_checker_spec.rb
@@ -473,6 +473,15 @@
         end
 
         it { is_expected.to be_truthy }
+
+        it "explains why the update was not possible" do
+          subject
+          expect(checker.blocked_by_parent_msg).to eq(
+            "dummy-pkg-a cannot be "\
+            "updated to 2.0.0 because it is locked by dummy-pkg-b (1.0.0) which "\
+            "requires dummy-pkg-a < 2.0.0"
+          )
+        end
       end
     end
   end

From 5eb95716464891a478a641eeacba870d9ae4638e Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Tue, 3 Nov 2020 16:42:53 +0100
Subject: [PATCH 03/13] Extract new native helper to detect blocking parent

---
 bundler/helpers/lib/functions.rb              | 31 ++++++---
 .../helpers/lib/functions/force_updater.rb    | 21 +-----
 .../functions/parent_dependency_resolver.rb   | 53 +++++++++++++++
 .../lib/dependabot/bundler/update_checker.rb  | 17 +++--
 .../parent_dependency_resolver.rb             | 64 +++++++++++++++++++
 .../dependabot/bundler/update_checker_spec.rb | 56 +++++++++++++---
 .../parent_dependency_resolver_spec.rb        | 44 +++++++++++++
 common/lib/dependabot/update_checkers/base.rb |  4 ++
 8 files changed, 247 insertions(+), 43 deletions(-)
 create mode 100644 bundler/helpers/lib/functions/parent_dependency_resolver.rb
 create mode 100644 bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
 create mode 100644 bundler/spec/native_helpers/functions/parent_dependency_resolver_spec.rb

diff --git a/bundler/helpers/lib/functions.rb b/bundler/helpers/lib/functions.rb
index 4475148438..0e656fcd2a 100644
--- a/bundler/helpers/lib/functions.rb
+++ b/bundler/helpers/lib/functions.rb
@@ -3,6 +3,7 @@
 require "functions/lockfile_updater"
 require "functions/dependency_source"
 require "functions/version_resolver"
+require "functions/parent_dependency_resolver"
 
 module Functions
   def self.parsed_gemfile(lockfile_name:, gemfile_name:, dir:)
@@ -32,7 +33,7 @@ def self.update_lockfile(dir:, gemfile_name:, lockfile_name:, using_bundler_2:,
     LockfileUpdater.new(
       gemfile_name: gemfile_name,
       lockfile_name: lockfile_name,
-      dependencies: dependencies,
+      dependencies: dependencies
     ).run
   end
 
@@ -46,7 +47,7 @@ def self.force_update(dir:, dependency_name:, target_version:, gemfile_name:,
       target_version: target_version,
       gemfile_name: gemfile_name,
       lockfile_name: lockfile_name,
-      update_multiple_dependencies: update_multiple_dependencies,
+      update_multiple_dependencies: update_multiple_dependencies
     ).run
   end
 
@@ -57,7 +58,7 @@ def self.dependency_source_type(gemfile_name:, dependency_name:, dir:,
 
     DependencySource.new(
       gemfile_name: gemfile_name,
-      dependency_name: dependency_name,
+      dependency_name: dependency_name
     ).type
   end
 
@@ -69,7 +70,7 @@ def self.depencency_source_latest_git_version(gemfile_name:, dependency_name:,
                                       using_bundler_2: false)
     DependencySource.new(
       gemfile_name: gemfile_name,
-      dependency_name: dependency_name,
+      dependency_name: dependency_name
     ).latest_git_version(
       dependency_source_url: dependency_source_url,
       dependency_source_branch: dependency_source_branch
@@ -83,7 +84,7 @@ def self.private_registry_versions(gemfile_name:, dependency_name:, dir:,
 
     DependencySource.new(
       gemfile_name: gemfile_name,
-      dependency_name: dependency_name,
+      dependency_name: dependency_name
     ).private_registry_versions
   end
 
@@ -96,7 +97,7 @@ def self.resolve_version(dependency_name:, dependency_requirements:,
       dependency_name: dependency_name,
       dependency_requirements: dependency_requirements,
       gemfile_name: gemfile_name,
-      lockfile_name: lockfile_name,
+      lockfile_name: lockfile_name
     ).version_details
   end
 
@@ -117,9 +118,9 @@ def self.git_specs(dir:, gemfile_name:, credentials:, using_bundler_2:)
                                       using_bundler_2: using_bundler_2)
 
     git_specs = Bundler::Definition.build(gemfile_name, nil, {}).dependencies.
-      select do |spec|
-        spec.source.is_a?(Bundler::Source::Git)
-      end
+                select do |spec|
+      spec.source.is_a?(Bundler::Source::Git)
+    end
     git_specs.map do |spec|
       # Piggy-back off some private Bundler methods to configure the
       # URI with auth details in the same way Bundler does.
@@ -161,4 +162,16 @@ def self.set_bundler_flags_and_credentials(dir:, credentials:,
       Bundler.settings.set_command_option("github.https", "true")
     end
   end
+
+  def self.blocking_parent_dependencies(dir:, dependency_name:, target_version:,
+                                        lockfile_name:, using_bundler_2:,
+                                        credentials:)
+    set_bundler_flags_and_credentials(dir: dir, credentials: credentials,
+                                      using_bundler_2: using_bundler_2)
+    ParentDependencyResolver.new(
+      dependency_name: dependency_name,
+      target_version: target_version,
+      lockfile_name: lockfile_name
+    ).blocking_parent_dependencies
+  end
 end
diff --git a/bundler/helpers/lib/functions/force_updater.rb b/bundler/helpers/lib/functions/force_updater.rb
index 90e75efc33..5a726cd6a4 100644
--- a/bundler/helpers/lib/functions/force_updater.rb
+++ b/bundler/helpers/lib/functions/force_updater.rb
@@ -120,7 +120,7 @@ def build_definition(other_updates:)
 
       # If the dependency is not found in the Gemfile it means this is a
       # transitive dependency that we can't force update.
-      raise TransitiveDependencyError, locked_by_parent_msg unless dep
+      raise TransitiveDependencyError unless dep
 
       dep.instance_variable_set(:@requirement, new_req)
       dep.source = nil if dep.source.is_a?(Bundler::Source::Git)
@@ -153,25 +153,6 @@ def subdependencies
       all_deps - top_level
     end
 
-    def locked_by_parent_msg
-      version = Gem::Version.new(target_version)
-      specs = Bundler::LockfileParser.new(lockfile).specs.filter do |spec|
-        spec.dependencies.any? do |sub_dep|
-          sub_dep.name == dependency_name &&
-            !sub_dep.requirement.satisfied_by?(version)
-        end
-      end
-
-      locking = specs.map do |spec|
-        req = spec.dependencies.find { |bd| bd.name == dependency_name }
-        "#{spec.name} (#{spec.version}) which requires #{dependency_name} "\
-        "#{req.requirement}"
-      end
-
-      "#{dependency_name} cannot be updated to #{target_version} because it "\
-        "is locked by #{locking.join(', ')}"
-    end
-
     def unlock_gem(definition:, gem_name:)
       dep = definition.dependencies.find { |d| d.name == gem_name }
       version = definition.locked_gems.specs.
diff --git a/bundler/helpers/lib/functions/parent_dependency_resolver.rb b/bundler/helpers/lib/functions/parent_dependency_resolver.rb
new file mode 100644
index 0000000000..37626cfb30
--- /dev/null
+++ b/bundler/helpers/lib/functions/parent_dependency_resolver.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+module Functions
+  class ParentDependencyResolver
+    def initialize(dependency_name:, target_version:, lockfile_name:)
+      @dependency_name = dependency_name
+      @target_version = target_version
+      @lockfile_name = lockfile_name
+
+      Bundler.settings.set_command_option("only_update_to_newer_versions", true)
+    end
+
+    # @return [Array<Hash{Symbol => String}]
+    #   :name the blocking dependencies name
+    #   :version the version of the blocking dependency
+    #   :requirement the requirement on the target_dependency
+    def blocking_parent_dependencies
+      parent_specs.map do |spec|
+        req = spec.dependencies.find { |bd| bd.name == dependency_name }
+        {
+          name: spec.name,
+          version: spec.version.to_s,
+          requirement: req.requirement.to_s
+        }
+      end
+    end
+
+    private
+
+    attr_reader :dependency_name, :target_version, :lockfile_name
+
+    def parent_specs
+      version = Gem::Version.new(target_version)
+      Bundler::LockfileParser.new(lockfile).specs.filter do |spec|
+        spec.dependencies.any? do |sub_dep|
+          sub_dep.name == dependency_name &&
+            !sub_dep.requirement.satisfied_by?(version)
+        end
+      end
+    end
+
+    def lockfile
+      return @lockfile if defined?(@lockfile)
+
+      @lockfile =
+        begin
+          return unless lockfile_name && File.exist?(lockfile_name)
+
+          File.read(lockfile_name)
+        end
+    end
+  end
+end
diff --git a/bundler/lib/dependabot/bundler/update_checker.rb b/bundler/lib/dependabot/bundler/update_checker.rb
index 80cb6be2fd..47bac396d4 100644
--- a/bundler/lib/dependabot/bundler/update_checker.rb
+++ b/bundler/lib/dependabot/bundler/update_checker.rb
@@ -13,6 +13,7 @@ class UpdateChecker < Dependabot::UpdateCheckers::Base
       require_relative "update_checker/requirements_updater"
       require_relative "update_checker/version_resolver"
       require_relative "update_checker/latest_version_finder"
+      require_relative "update_checker/parent_dependency_resolver"
 
       def latest_version
         return latest_version_for_git_dependency if git_dependency?
@@ -107,7 +108,16 @@ def requirements_update_strategy
         dependency.version.nil? ? :bump_versions_if_necessary : :bump_versions
       end
 
-      attr_reader :blocked_by_parent_msg
+      def blocking_parent_dependencies
+        ParentDependencyResolver.new(
+          dependency_files: dependency_files,
+          repo_contents_path: repo_contents_path,
+          credentials: credentials
+        ).blocking_parent_dependencies(
+          dependency: dependency,
+          target_version: lowest_security_fix_version
+        )
+      end
 
       private
 
@@ -159,10 +169,7 @@ def resolvable?(version)
               update_multiple_dependencies: false
             ).updated_dependencies
             true
-          rescue Dependabot::DependencyFileNotResolvable => e
-            if e.error_class.end_with?("TransitiveDependencyError")
-              @blocked_by_parent_msg = e.msg
-            end
+          rescue Dependabot::DependencyFileNotResolvable
             false
           end
       end
diff --git a/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb b/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
new file mode 100644
index 0000000000..dc60aa82a9
--- /dev/null
+++ b/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+require "dependabot/bundler/native_helpers"
+require "dependabot/shared_helpers"
+
+module Dependabot
+  module Bundler
+    class UpdateChecker
+      class ParentDependencyResolver
+        require_relative "shared_bundler_helpers"
+        include SharedBundlerHelpers
+
+        def initialize(dependency_files:, repo_contents_path:, credentials:)
+          @dependency_files = dependency_files
+          @repo_contents_path = repo_contents_path
+          @credentials = credentials
+        end
+
+        def blocking_parent_dependencies(dependency:, target_version:)
+          in_a_native_bundler_context(error_handling: false) do |tmp_dir|
+            SharedHelpers.run_helper_subprocess(
+              command: NativeHelpers.helper_path,
+              function: "blocking_parent_dependencies",
+              args: {
+                dir: tmp_dir,
+                dependency_name: dependency.name,
+                target_version: target_version,
+                credentials: relevant_credentials,
+                lockfile_name: lockfile.name,
+                using_bundler_2: using_bundler_2?
+              }
+            )
+          end
+        end
+
+        private
+
+        attr_reader :dependency_files, :repo_contents_path, :credentials
+
+        def lockfile
+          (dependency_files.find { |f| f.name == "Gemfile.lock" } ||
+           dependency_files.find { |f| f.name == "gems.locked" })
+        end
+
+        def relevant_credentials
+          credentials.
+            select { |cred| cred["password"] || cred["token"] }.
+            select do |cred|
+              next true if cred["type"] == "git_source"
+              next true if cred["type"] == "rubygems_server"
+
+              false
+            end
+        end
+
+        def using_bundler_2?
+          return unless lockfile
+
+          lockfile.content.match?(/BUNDLED WITH\s+2/m)
+        end
+      end
+    end
+  end
+end
diff --git a/bundler/spec/dependabot/bundler/update_checker_spec.rb b/bundler/spec/dependabot/bundler/update_checker_spec.rb
index 41db9857bd..2c3430d600 100644
--- a/bundler/spec/dependabot/bundler/update_checker_spec.rb
+++ b/bundler/spec/dependabot/bundler/update_checker_spec.rb
@@ -473,15 +473,6 @@
         end
 
         it { is_expected.to be_truthy }
-
-        it "explains why the update was not possible" do
-          subject
-          expect(checker.blocked_by_parent_msg).to eq(
-            "dummy-pkg-a cannot be "\
-            "updated to 2.0.0 because it is locked by dummy-pkg-b (1.0.0) which "\
-            "requires dummy-pkg-a < 2.0.0"
-          )
-        end
       end
     end
   end
@@ -602,6 +593,53 @@
     end
   end
 
+  describe "#blocking_parent_dependencies" do
+    include_context "stub rubygems compact index"
+    include_context "stub rubygems versions api"
+
+    subject { checker.blocking_parent_dependencies }
+
+    let(:gemfile_fixture_name) { "subdep_blocked_by_subdep" }
+    let(:lockfile_fixture_name) { "subdep_blocked_by_subdep.lock" }
+    let(:target_version) { "2.0.0" }
+    let(:dependency_name) { "dummy-pkg-a" }
+    let(:requirements) do
+      [{
+        file: "Gemfile",
+        requirement: "~> 1.0.0",
+        groups: [],
+        source: nil
+      }]
+    end
+
+    let(:requirements) { [] }
+    let(:security_advisories) do
+      [
+        Dependabot::SecurityAdvisory.new(
+          dependency_name: dependency_name,
+          package_manager: "bundler",
+          vulnerable_versions: ["< 2.0.0"]
+        )
+      ]
+    end
+
+    before do
+      allow(checker).
+        to receive(:lowest_security_fix_version).
+        and_return(target_version)
+    end
+
+    it do
+      is_expected.to eq(
+        [{
+          "name" => "dummy-pkg-b",
+          "version" => "1.0.0",
+          "requirement" => "< 2.0.0"
+        }]
+      )
+    end
+  end
+
   describe "#latest_resolvable_version" do
     include_context "stub rubygems compact index"
     include_context "stub rubygems versions api"
diff --git a/bundler/spec/native_helpers/functions/parent_dependency_resolver_spec.rb b/bundler/spec/native_helpers/functions/parent_dependency_resolver_spec.rb
new file mode 100644
index 0000000000..0c049a3b4f
--- /dev/null
+++ b/bundler/spec/native_helpers/functions/parent_dependency_resolver_spec.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require "native_spec_helper"
+require "shared_contexts"
+
+RSpec.describe Functions::ParentDependencyResolver do
+  include_context "in a temporary bundler directory"
+
+  let(:parent_dependency_resolver) do
+    described_class.new(
+      dependency_name: dependency_name,
+      target_version: target_version,
+      lockfile_name: lockfile_name
+    )
+  end
+
+  let(:dependency_name) { "dummy-pkg-a" }
+  let(:target_version) { "2.0.0" }
+
+  let(:gemfile_fixture_name) { "blocked_by_subdep" }
+  let(:lockfile_fixture_name) { "blocked_by_subdep.lock" }
+
+  describe "#blocking_parent_dependencies" do
+    subject(:blocking_parent_dependencies) do
+      in_tmp_folder { parent_dependency_resolver.blocking_parent_dependencies }
+    end
+
+    it "returns a list of dependencies that block the update" do
+      expect(blocking_parent_dependencies).to eq(
+        [
+          { name: "dummy-pkg-b", version: "1.0.0", requirement: "< 2.0.0" }
+        ]
+      )
+    end
+
+    context "without any blocking dependencies" do
+      let(:target_version) { "1.0.0" }
+
+      it "returns an empty list" do
+        expect(blocking_parent_dependencies).to eq([])
+      end
+    end
+  end
+end
diff --git a/common/lib/dependabot/update_checkers/base.rb b/common/lib/dependabot/update_checkers/base.rb
index c1130a1050..6cf9d66755 100644
--- a/common/lib/dependabot/update_checkers/base.rb
+++ b/common/lib/dependabot/update_checkers/base.rb
@@ -93,6 +93,10 @@ def latest_resolvable_version_with_no_unlock
         raise NotImplementedError
       end
 
+      def blocking_parent_dependencies
+        raise NotImplementedError
+      end
+
       def latest_resolvable_previous_version(_updated_version)
         dependency.version
       end

From d048df2e6327bc3c290803b6b7fca8969fe14f03 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 14:22:55 +0100
Subject: [PATCH 04/13] Output blocking parents in dry-run

---
 bin/dry-run.rb | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/bin/dry-run.rb b/bin/dry-run.rb
index 69f9f82d75..b44f494003 100755
--- a/bin/dry-run.rb
+++ b/bin/dry-run.rb
@@ -102,7 +102,7 @@
   commit: nil,
   updater_options: {},
   security_advisories: [],
-  security_updates_only: false,
+  security_updates_only: false
 }
 
 unless ENV["LOCAL_GITHUB_ACCESS_TOKEN"].to_s.strip.empty?
@@ -424,7 +424,7 @@ def file_updater_for(dependencies)
     dependency_files: $files,
     repo_contents_path: $repo_contents_path,
     credentials: $options[:credentials],
-    options: $options[:updater_options],
+    options: $options[:updater_options]
   )
 end
 
@@ -482,11 +482,23 @@ def security_fix?(dependency)
     end
   end
 
-  latest_allowed_version = checker.vulnerable? ?
-    checker.lowest_resolvable_security_fix_version :
-    checker.latest_resolvable_version
+  latest_allowed_version = if checker.vulnerable?
+                             checker.lowest_resolvable_security_fix_version
+                           else
+                             checker.latest_resolvable_version
+                           end
   puts " => latest allowed version is #{latest_allowed_version || dep.version}"
 
+  parents = checker.blocking_parent_dependencies
+  if parents.any?
+    puts " => The update is not possible because of the following conflicting "\
+      "dependencies:"
+  end
+  parents.each do |parent|
+    puts "   #{parent['name']} (#{parent['version']}) which requires:"
+    puts "     #{dep.name} #{parent['requirement']}"
+  end
+
   if checker.up_to_date?
     puts "    (no update needed as it's already up-to-date)"
     next

From f2926d1404c96659d999671a21430109ac88bb48 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 14:23:04 +0100
Subject: [PATCH 05/13] Clean up Bundler parent dependency resolving and
 improve test coverage

---
 .../functions/parent_dependency_resolver.rb   |  16 +--
 .../parent_dependency_resolver.rb             |  38 ++----
 .../parent_dependency_resolver_spec.rb        | 109 ++++++++++++++++++
 .../fixtures/ruby/gemfiles/multiple_blocking  |   5 +
 .../ruby/lockfiles/multiple_blocking.lock     |  70 +++++++++++
 common/lib/dependabot/update_checkers/base.rb |   8 +-
 6 files changed, 211 insertions(+), 35 deletions(-)
 create mode 100644 bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
 create mode 100644 bundler/spec/fixtures/ruby/gemfiles/multiple_blocking
 create mode 100644 bundler/spec/fixtures/ruby/lockfiles/multiple_blocking.lock

diff --git a/bundler/helpers/lib/functions/parent_dependency_resolver.rb b/bundler/helpers/lib/functions/parent_dependency_resolver.rb
index 37626cfb30..9f16c960bc 100644
--- a/bundler/helpers/lib/functions/parent_dependency_resolver.rb
+++ b/bundler/helpers/lib/functions/parent_dependency_resolver.rb
@@ -10,17 +10,19 @@ def initialize(dependency_name:, target_version:, lockfile_name:)
       Bundler.settings.set_command_option("only_update_to_newer_versions", true)
     end
 
-    # @return [Array<Hash{Symbol => String}]
-    #   :name the blocking dependencies name
-    #   :version the version of the blocking dependency
-    #   :requirement the requirement on the target_dependency
+    # Finds any dependencies in the lockfile that have a subdependency on the
+    # given dependency that does not satisfly the target_version.
+    # @return [Array<Hash{String => String}]
+    #   * name [String] the blocking dependencies name
+    #   * version [String] the version of the blocking dependency
+    #   * requirement [String] the requirement on the target_dependency
     def blocking_parent_dependencies
       parent_specs.map do |spec|
         req = spec.dependencies.find { |bd| bd.name == dependency_name }
         {
-          name: spec.name,
-          version: spec.version.to_s,
-          requirement: req.requirement.to_s
+          "name" => spec.name,
+          "version" => spec.version.to_s,
+          "requirement" => req.requirement.to_s
         }
       end
     end
diff --git a/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb b/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
index dc60aa82a9..8bcb0fc270 100644
--- a/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
+++ b/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
@@ -1,11 +1,12 @@
 # frozen_string_literal: true
 
+require "dependabot/bundler/update_checker"
 require "dependabot/bundler/native_helpers"
 require "dependabot/shared_helpers"
 
 module Dependabot
   module Bundler
-    class UpdateChecker
+    class UpdateChecker < UpdateCheckers::Base
       class ParentDependencyResolver
         require_relative "shared_bundler_helpers"
         include SharedBundlerHelpers
@@ -16,6 +17,15 @@ def initialize(dependency_files:, repo_contents_path:, credentials:)
           @credentials = credentials
         end
 
+        # Finds any dependencies in the lockfile that have a subdependency on
+        # the given dependency that does not satisfly the target_version.
+        #
+        # @param dependency [Dependabot::Dependency] the dependency to check
+        # @param target_version [String] the version to check
+        # @return [Array<Hash{String => String}]
+        #   * name [String] the blocking dependencies name
+        #   * version [String] the version of the blocking dependency
+        #   * requirement [String] the requirement on the target_dependency
         def blocking_parent_dependencies(dependency:, target_version:)
           in_a_native_bundler_context(error_handling: false) do |tmp_dir|
             SharedHelpers.run_helper_subprocess(
@@ -32,32 +42,6 @@ def blocking_parent_dependencies(dependency:, target_version:)
             )
           end
         end
-
-        private
-
-        attr_reader :dependency_files, :repo_contents_path, :credentials
-
-        def lockfile
-          (dependency_files.find { |f| f.name == "Gemfile.lock" } ||
-           dependency_files.find { |f| f.name == "gems.locked" })
-        end
-
-        def relevant_credentials
-          credentials.
-            select { |cred| cred["password"] || cred["token"] }.
-            select do |cred|
-              next true if cred["type"] == "git_source"
-              next true if cred["type"] == "rubygems_server"
-
-              false
-            end
-        end
-
-        def using_bundler_2?
-          return unless lockfile
-
-          lockfile.content.match?(/BUNDLED WITH\s+2/m)
-        end
       end
     end
   end
diff --git a/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
new file mode 100644
index 0000000000..eacc9dd4df
--- /dev/null
+++ b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
@@ -0,0 +1,109 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "shared_contexts"
+require "dependabot/dependency"
+require "dependabot/dependency_file"
+require "dependabot/bundler/update_checker/parent_dependency_resolver"
+
+RSpec.describe Dependabot::Bundler::UpdateChecker::ParentDependencyResolver do
+  include_context "stub rubygems compact index"
+
+  let(:resolver) do
+    described_class.new(
+      dependency_files: dependency_files,
+      repo_contents_path: repo_contents_path,
+      credentials: [{
+        "type" => "git_source",
+        "host" => "github.com",
+        "username" => "x-access-token",
+        "password" => "token"
+      }]
+    )
+  end
+  let(:dependency_files) { [gemfile, lockfile] }
+  let(:repo_contents_path) { nil }
+
+  let(:dependency) do
+    Dependabot::Dependency.new(
+      name: dependency_name,
+      version: current_version,
+      requirements: [],
+      package_manager: "bundler"
+    )
+  end
+  let(:dependency_name) { "dummy-pkg-a" }
+  let(:current_version) { "1.0.1" }
+  let(:target_version) { "2.0.0" }
+
+  let(:gemfile) do
+    Dependabot::DependencyFile.new(content: gemfile_body, name: "Gemfile")
+  end
+  let(:lockfile) do
+    Dependabot::DependencyFile.new(content: lockfile_body, name: "Gemfile.lock")
+  end
+  let(:gemfile_body) { fixture("ruby", "gemfiles", "subdep_blocked_by_subdep") }
+  let(:lockfile_body) do
+    fixture("ruby", "lockfiles", "subdep_blocked_by_subdep.lock")
+  end
+
+  describe "#blocking_parent_dependencies" do
+    subject(:blocking_parent_dependencies) do
+      resolver.blocking_parent_dependencies(
+        dependency: dependency,
+        target_version: target_version
+      )
+    end
+
+    it "returns the right array of updated dependencies" do
+      expect(blocking_parent_dependencies).to match_array(
+        [
+          {
+            "name" => "dummy-pkg-b",
+            "version" => "1.0.0",
+            "requirement" => "< 2.0.0"
+          }
+        ]
+      )
+    end
+
+    context "with no blocking dependencies" do
+      let(:target_version) { "1.5.0" }
+      it "returns an empty array" do
+        expect(blocking_parent_dependencies).to match_array([])
+      end
+    end
+
+    context "with multiple blocking dependencies" do
+      let(:dependency_name) { "activesupport" }
+      let(:current_version) { "5.0.0" }
+      let(:target_version) { "6.0.0" }
+      let(:gemfile_body) { fixture("ruby", "gemfiles", "multiple_blocking") }
+      let(:lockfile_body) do
+        fixture("ruby", "lockfiles", "multiple_blocking.lock")
+      end
+
+      it "returns all of the blocking dependencies" do
+        expect(blocking_parent_dependencies).to match_array(
+          [
+            {
+              "name" => "actionpack",
+              "version" => "5.0.0",
+              "requirement" => "= 5.0.0"
+            },
+            {
+              "name" => "actionview",
+              "version" => "5.0.0",
+              "requirement" => "= 5.0.0"
+            },
+            {
+              "name" => "activejob",
+              "version" => "5.0.0",
+              "requirement" => "= 5.0.0"
+            }
+          ]
+        )
+      end
+    end
+  end
+end
diff --git a/bundler/spec/fixtures/ruby/gemfiles/multiple_blocking b/bundler/spec/fixtures/ruby/gemfiles/multiple_blocking
new file mode 100644
index 0000000000..eb7111e1ad
--- /dev/null
+++ b/bundler/spec/fixtures/ruby/gemfiles/multiple_blocking
@@ -0,0 +1,5 @@
+source "https://rubygems.org"
+
+gem "activesupport", "5.0.0"
+gem "actionview", "5.0.0"
+gem "actionmailer", "5.0.0"
diff --git a/bundler/spec/fixtures/ruby/lockfiles/multiple_blocking.lock b/bundler/spec/fixtures/ruby/lockfiles/multiple_blocking.lock
new file mode 100644
index 0000000000..2555bab90b
--- /dev/null
+++ b/bundler/spec/fixtures/ruby/lockfiles/multiple_blocking.lock
@@ -0,0 +1,70 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actionmailer (5.0.0)
+      actionpack (= 5.0.0)
+      actionview (= 5.0.0)
+      activejob (= 5.0.0)
+      mail (~> 2.5, >= 2.5.4)
+      rails-dom-testing (~> 2.0)
+    actionpack (5.0.0)
+      actionview (= 5.0.0)
+      activesupport (= 5.0.0)
+      rack (~> 2.0)
+      rack-test (~> 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionview (5.0.0)
+      activesupport (= 5.0.0)
+      builder (~> 3.1)
+      erubis (~> 2.7.0)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    activejob (5.0.0)
+      activesupport (= 5.0.0)
+      globalid (>= 0.3.6)
+    activesupport (5.0.0)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (~> 0.7)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    builder (3.2.4)
+    concurrent-ruby (1.1.7)
+    crass (1.0.6)
+    erubis (2.7.0)
+    globalid (0.4.2)
+      activesupport (>= 4.2.0)
+    i18n (0.9.5)
+      concurrent-ruby (~> 1.0)
+    loofah (2.7.0)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    mini_mime (1.0.2)
+    mini_portile2 (2.4.0)
+    minitest (5.14.2)
+    nokogiri (1.10.10)
+      mini_portile2 (~> 2.4.0)
+    rack (2.2.3)
+    rack-test (0.6.3)
+      rack (>= 1.0)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    thread_safe (0.3.6)
+    tzinfo (1.2.7)
+      thread_safe (~> 0.1)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  actionmailer (= 5.0.0)
+  actionview (= 5.0.0)
+  activesupport (= 5.0.0)
+
+BUNDLED WITH
+   2.1.4
diff --git a/common/lib/dependabot/update_checkers/base.rb b/common/lib/dependabot/update_checkers/base.rb
index 6cf9d66755..b73ca2c3fc 100644
--- a/common/lib/dependabot/update_checkers/base.rb
+++ b/common/lib/dependabot/update_checkers/base.rb
@@ -93,8 +93,14 @@ def latest_resolvable_version_with_no_unlock
         raise NotImplementedError
       end
 
+      # Finds any dependencies in the lockfile that have a subdependency on the
+      # given dependency that do not satisfly the target_version.
+      # @return [Array<Hash{String => String}]
+      #   name [String] the blocking dependencies name
+      #   version [String] the version of the blocking dependency
+      #   requirement [String] the requirement on the target_dependency
       def blocking_parent_dependencies
-        raise NotImplementedError
+        [] # return an empty array for ecosystems that don't support this yet
       end
 
       def latest_resolvable_previous_version(_updated_version)

From 31bb936f0de979ab057bfecd93198207ee952b74 Mon Sep 17 00:00:00 2001
From: Jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 15:38:29 +0100
Subject: [PATCH 06/13] Fix typo in
 common/lib/dependabot/update_checkers/base.rb

Co-authored-by: Pete Wagner <thepwagner@github.com>
---
 common/lib/dependabot/update_checkers/base.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/lib/dependabot/update_checkers/base.rb b/common/lib/dependabot/update_checkers/base.rb
index b73ca2c3fc..1491decc3c 100644
--- a/common/lib/dependabot/update_checkers/base.rb
+++ b/common/lib/dependabot/update_checkers/base.rb
@@ -94,7 +94,7 @@ def latest_resolvable_version_with_no_unlock
       end
 
       # Finds any dependencies in the lockfile that have a subdependency on the
-      # given dependency that do not satisfly the target_version.
+      # given dependency that do not satisfy the target_version.
       # @return [Array<Hash{String => String}]
       #   name [String] the blocking dependencies name
       #   version [String] the version of the blocking dependency

From f808848d4a4ec0781af66d475da0fdede11e74bd Mon Sep 17 00:00:00 2001
From: Jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 15:38:45 +0100
Subject: [PATCH 07/13] Fix typo in
 bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb

Co-authored-by: Pete Wagner <thepwagner@github.com>
---
 .../bundler/update_checker/parent_dependency_resolver_spec.rb   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
index eacc9dd4df..e0c35edb65 100644
--- a/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
+++ b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
@@ -55,7 +55,7 @@
       )
     end
 
-    it "returns the right array of updated dependencies" do
+    it "returns the right array of blocking dependencies" do
       expect(blocking_parent_dependencies).to match_array(
         [
           {

From e93d7b56c50895b19923a7820e044d5cf1873af1 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 15:35:39 +0100
Subject: [PATCH 08/13] Don't modify static state from constructor

---
 bundler/helpers/lib/functions/parent_dependency_resolver.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/bundler/helpers/lib/functions/parent_dependency_resolver.rb b/bundler/helpers/lib/functions/parent_dependency_resolver.rb
index 9f16c960bc..c1978cb597 100644
--- a/bundler/helpers/lib/functions/parent_dependency_resolver.rb
+++ b/bundler/helpers/lib/functions/parent_dependency_resolver.rb
@@ -6,8 +6,6 @@ def initialize(dependency_name:, target_version:, lockfile_name:)
       @dependency_name = dependency_name
       @target_version = target_version
       @lockfile_name = lockfile_name
-
-      Bundler.settings.set_command_option("only_update_to_newer_versions", true)
     end
 
     # Finds any dependencies in the lockfile that have a subdependency on the
@@ -17,6 +15,8 @@ def initialize(dependency_name:, target_version:, lockfile_name:)
     #   * version [String] the version of the blocking dependency
     #   * requirement [String] the requirement on the target_dependency
     def blocking_parent_dependencies
+      Bundler.settings.set_command_option("only_update_to_newer_versions", true)
+
       parent_specs.map do |spec|
         req = spec.dependencies.find { |bd| bd.name == dependency_name }
         {

From 7735d847c7ce95c78d62525d5e954153426562a2 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 15:36:22 +0100
Subject: [PATCH 09/13] Move local variable closer to where it's used

---
 bundler/helpers/lib/functions/force_updater.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/bundler/helpers/lib/functions/force_updater.rb b/bundler/helpers/lib/functions/force_updater.rb
index 5a726cd6a4..dad2343ac0 100644
--- a/bundler/helpers/lib/functions/force_updater.rb
+++ b/bundler/helpers/lib/functions/force_updater.rb
@@ -113,8 +113,6 @@ def build_definition(other_updates:)
         unlock_gem(definition: definition, gem_name: gem_name)
       end
 
-      # Set the requirement for the gem we're forcing an update of
-      new_req = Gem::Requirement.create("= #{target_version}")
       dep = definition.dependencies.
             find { |d| d.name == dependency_name }
 
@@ -122,6 +120,8 @@ def build_definition(other_updates:)
       # transitive dependency that we can't force update.
       raise TransitiveDependencyError unless dep
 
+      # Set the requirement for the gem we're forcing an update of
+      new_req = Gem::Requirement.create("= #{target_version}")
       dep.instance_variable_set(:@requirement, new_req)
       dep.source = nil if dep.source.is_a?(Bundler::Source::Git)
 

From 0b3aafcba8ecac74a7d45e81fc90ef19fd037ad8 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 15:39:39 +0100
Subject: [PATCH 10/13] Remove unused let

---
 .../bundler/update_checker/parent_dependency_resolver_spec.rb  | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
index e0c35edb65..feade3e776 100644
--- a/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
+++ b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
@@ -12,7 +12,7 @@
   let(:resolver) do
     described_class.new(
       dependency_files: dependency_files,
-      repo_contents_path: repo_contents_path,
+      repo_contents_path: nil,
       credentials: [{
         "type" => "git_source",
         "host" => "github.com",
@@ -22,7 +22,6 @@
     )
   end
   let(:dependency_files) { [gemfile, lockfile] }
-  let(:repo_contents_path) { nil }
 
   let(:dependency) do
     Dependabot::Dependency.new(

From 3197f2f36eb56e993fe1777683ed2fdf5d61f2a8 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 15:42:03 +0100
Subject: [PATCH 11/13] Rename blocking_parent_dependencies to
 conflicting_dependencies

---
 bin/dry-run.rb                                 |  2 +-
 bundler/helpers/lib/functions.rb               | 11 +++++------
 ...r.rb => conflicting_dependency_resolver.rb} |  4 ++--
 .../lib/dependabot/bundler/update_checker.rb   |  8 ++++----
 ...r.rb => conflicting_dependency_resolver.rb} |  6 +++---
 .../parent_dependency_resolver_spec.rb         | 18 ++++++++++--------
 .../dependabot/bundler/update_checker_spec.rb  |  4 ++--
 ...=> conflicting_dependency_resolver_spec.rb} | 14 +++++++-------
 common/lib/dependabot/update_checkers/base.rb  |  2 +-
 9 files changed, 35 insertions(+), 34 deletions(-)
 rename bundler/helpers/lib/functions/{parent_dependency_resolver.rb => conflicting_dependency_resolver.rb} (95%)
 rename bundler/lib/dependabot/bundler/update_checker/{parent_dependency_resolver.rb => conflicting_dependency_resolver.rb} (91%)
 rename bundler/spec/native_helpers/functions/{parent_dependency_resolver_spec.rb => conflicting_dependency_resolver_spec.rb} (69%)

diff --git a/bin/dry-run.rb b/bin/dry-run.rb
index b44f494003..e31b2fb18e 100755
--- a/bin/dry-run.rb
+++ b/bin/dry-run.rb
@@ -489,7 +489,7 @@ def security_fix?(dependency)
                            end
   puts " => latest allowed version is #{latest_allowed_version || dep.version}"
 
-  parents = checker.blocking_parent_dependencies
+  parents = checker.conflicting_dependencies
   if parents.any?
     puts " => The update is not possible because of the following conflicting "\
       "dependencies:"
diff --git a/bundler/helpers/lib/functions.rb b/bundler/helpers/lib/functions.rb
index 0e656fcd2a..f1e199639f 100644
--- a/bundler/helpers/lib/functions.rb
+++ b/bundler/helpers/lib/functions.rb
@@ -3,7 +3,7 @@
 require "functions/lockfile_updater"
 require "functions/dependency_source"
 require "functions/version_resolver"
-require "functions/parent_dependency_resolver"
+require "functions/conflicting_dependency_resolver"
 
 module Functions
   def self.parsed_gemfile(lockfile_name:, gemfile_name:, dir:)
@@ -163,15 +163,14 @@ def self.set_bundler_flags_and_credentials(dir:, credentials:,
     end
   end
 
-  def self.blocking_parent_dependencies(dir:, dependency_name:, target_version:,
-                                        lockfile_name:, using_bundler_2:,
-                                        credentials:)
+  def self.conflicting_dependencies(dir:, dependency_name:, target_version:,
+                                    lockfile_name:, using_bundler_2:, credentials:)
     set_bundler_flags_and_credentials(dir: dir, credentials: credentials,
                                       using_bundler_2: using_bundler_2)
-    ParentDependencyResolver.new(
+    ConflictingDependencyResolver.new(
       dependency_name: dependency_name,
       target_version: target_version,
       lockfile_name: lockfile_name
-    ).blocking_parent_dependencies
+    ).conflicting_dependencies
   end
 end
diff --git a/bundler/helpers/lib/functions/parent_dependency_resolver.rb b/bundler/helpers/lib/functions/conflicting_dependency_resolver.rb
similarity index 95%
rename from bundler/helpers/lib/functions/parent_dependency_resolver.rb
rename to bundler/helpers/lib/functions/conflicting_dependency_resolver.rb
index c1978cb597..7085a30947 100644
--- a/bundler/helpers/lib/functions/parent_dependency_resolver.rb
+++ b/bundler/helpers/lib/functions/conflicting_dependency_resolver.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module Functions
-  class ParentDependencyResolver
+  class ConflictingDependencyResolver
     def initialize(dependency_name:, target_version:, lockfile_name:)
       @dependency_name = dependency_name
       @target_version = target_version
@@ -14,7 +14,7 @@ def initialize(dependency_name:, target_version:, lockfile_name:)
     #   * name [String] the blocking dependencies name
     #   * version [String] the version of the blocking dependency
     #   * requirement [String] the requirement on the target_dependency
-    def blocking_parent_dependencies
+    def conflicting_dependencies
       Bundler.settings.set_command_option("only_update_to_newer_versions", true)
 
       parent_specs.map do |spec|
diff --git a/bundler/lib/dependabot/bundler/update_checker.rb b/bundler/lib/dependabot/bundler/update_checker.rb
index 47bac396d4..fe6ba35a2d 100644
--- a/bundler/lib/dependabot/bundler/update_checker.rb
+++ b/bundler/lib/dependabot/bundler/update_checker.rb
@@ -13,7 +13,7 @@ class UpdateChecker < Dependabot::UpdateCheckers::Base
       require_relative "update_checker/requirements_updater"
       require_relative "update_checker/version_resolver"
       require_relative "update_checker/latest_version_finder"
-      require_relative "update_checker/parent_dependency_resolver"
+      require_relative "update_checker/conflicting_dependency_resolver"
 
       def latest_version
         return latest_version_for_git_dependency if git_dependency?
@@ -108,12 +108,12 @@ def requirements_update_strategy
         dependency.version.nil? ? :bump_versions_if_necessary : :bump_versions
       end
 
-      def blocking_parent_dependencies
-        ParentDependencyResolver.new(
+      def conflicting_dependencies
+        ConflictingDependencyResolver.new(
           dependency_files: dependency_files,
           repo_contents_path: repo_contents_path,
           credentials: credentials
-        ).blocking_parent_dependencies(
+        ).conflicting_dependencies(
           dependency: dependency,
           target_version: lowest_security_fix_version
         )
diff --git a/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb b/bundler/lib/dependabot/bundler/update_checker/conflicting_dependency_resolver.rb
similarity index 91%
rename from bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
rename to bundler/lib/dependabot/bundler/update_checker/conflicting_dependency_resolver.rb
index 8bcb0fc270..9b23b894e2 100644
--- a/bundler/lib/dependabot/bundler/update_checker/parent_dependency_resolver.rb
+++ b/bundler/lib/dependabot/bundler/update_checker/conflicting_dependency_resolver.rb
@@ -7,7 +7,7 @@
 module Dependabot
   module Bundler
     class UpdateChecker < UpdateCheckers::Base
-      class ParentDependencyResolver
+      class ConflictingDependencyResolver
         require_relative "shared_bundler_helpers"
         include SharedBundlerHelpers
 
@@ -26,11 +26,11 @@ def initialize(dependency_files:, repo_contents_path:, credentials:)
         #   * name [String] the blocking dependencies name
         #   * version [String] the version of the blocking dependency
         #   * requirement [String] the requirement on the target_dependency
-        def blocking_parent_dependencies(dependency:, target_version:)
+        def conflicting_dependencies(dependency:, target_version:)
           in_a_native_bundler_context(error_handling: false) do |tmp_dir|
             SharedHelpers.run_helper_subprocess(
               command: NativeHelpers.helper_path,
-              function: "blocking_parent_dependencies",
+              function: "conflicting_dependencies",
               args: {
                 dir: tmp_dir,
                 dependency_name: dependency.name,
diff --git a/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
index feade3e776..a5e4b99bdf 100644
--- a/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
+++ b/bundler/spec/dependabot/bundler/update_checker/parent_dependency_resolver_spec.rb
@@ -4,9 +4,11 @@
 require "shared_contexts"
 require "dependabot/dependency"
 require "dependabot/dependency_file"
-require "dependabot/bundler/update_checker/parent_dependency_resolver"
+require "dependabot/bundler/update_checker/conflicting_dependency_resolver"
 
-RSpec.describe Dependabot::Bundler::UpdateChecker::ParentDependencyResolver do
+RSpec.describe(
+  Dependabot::Bundler::UpdateChecker::ConflictingDependencyResolver
+) do
   include_context "stub rubygems compact index"
 
   let(:resolver) do
@@ -46,16 +48,16 @@
     fixture("ruby", "lockfiles", "subdep_blocked_by_subdep.lock")
   end
 
-  describe "#blocking_parent_dependencies" do
-    subject(:blocking_parent_dependencies) do
-      resolver.blocking_parent_dependencies(
+  describe "#conflicting_dependencies" do
+    subject(:conflicting_dependencies) do
+      resolver.conflicting_dependencies(
         dependency: dependency,
         target_version: target_version
       )
     end
 
     it "returns the right array of blocking dependencies" do
-      expect(blocking_parent_dependencies).to match_array(
+      expect(conflicting_dependencies).to match_array(
         [
           {
             "name" => "dummy-pkg-b",
@@ -69,7 +71,7 @@
     context "with no blocking dependencies" do
       let(:target_version) { "1.5.0" }
       it "returns an empty array" do
-        expect(blocking_parent_dependencies).to match_array([])
+        expect(conflicting_dependencies).to match_array([])
       end
     end
 
@@ -83,7 +85,7 @@
       end
 
       it "returns all of the blocking dependencies" do
-        expect(blocking_parent_dependencies).to match_array(
+        expect(conflicting_dependencies).to match_array(
           [
             {
               "name" => "actionpack",
diff --git a/bundler/spec/dependabot/bundler/update_checker_spec.rb b/bundler/spec/dependabot/bundler/update_checker_spec.rb
index 2c3430d600..0d829a0805 100644
--- a/bundler/spec/dependabot/bundler/update_checker_spec.rb
+++ b/bundler/spec/dependabot/bundler/update_checker_spec.rb
@@ -593,11 +593,11 @@
     end
   end
 
-  describe "#blocking_parent_dependencies" do
+  describe "#conflicting_dependencies" do
     include_context "stub rubygems compact index"
     include_context "stub rubygems versions api"
 
-    subject { checker.blocking_parent_dependencies }
+    subject { checker.conflicting_dependencies }
 
     let(:gemfile_fixture_name) { "subdep_blocked_by_subdep" }
     let(:lockfile_fixture_name) { "subdep_blocked_by_subdep.lock" }
diff --git a/bundler/spec/native_helpers/functions/parent_dependency_resolver_spec.rb b/bundler/spec/native_helpers/functions/conflicting_dependency_resolver_spec.rb
similarity index 69%
rename from bundler/spec/native_helpers/functions/parent_dependency_resolver_spec.rb
rename to bundler/spec/native_helpers/functions/conflicting_dependency_resolver_spec.rb
index 0c049a3b4f..09320b0ae2 100644
--- a/bundler/spec/native_helpers/functions/parent_dependency_resolver_spec.rb
+++ b/bundler/spec/native_helpers/functions/conflicting_dependency_resolver_spec.rb
@@ -3,10 +3,10 @@
 require "native_spec_helper"
 require "shared_contexts"
 
-RSpec.describe Functions::ParentDependencyResolver do
+RSpec.describe Functions::ConflictingDependencyResolver do
   include_context "in a temporary bundler directory"
 
-  let(:parent_dependency_resolver) do
+  let(:conflicting_dependency_resolver) do
     described_class.new(
       dependency_name: dependency_name,
       target_version: target_version,
@@ -20,13 +20,13 @@
   let(:gemfile_fixture_name) { "blocked_by_subdep" }
   let(:lockfile_fixture_name) { "blocked_by_subdep.lock" }
 
-  describe "#blocking_parent_dependencies" do
-    subject(:blocking_parent_dependencies) do
-      in_tmp_folder { parent_dependency_resolver.blocking_parent_dependencies }
+  describe "#conflicting_dependencies" do
+    subject(:conflicting_dependencies) do
+      in_tmp_folder { conflicting_dependency_resolver.conflicting_dependencies }
     end
 
     it "returns a list of dependencies that block the update" do
-      expect(blocking_parent_dependencies).to eq(
+      expect(conflicting_dependencies).to eq(
         [
           { name: "dummy-pkg-b", version: "1.0.0", requirement: "< 2.0.0" }
         ]
@@ -37,7 +37,7 @@
       let(:target_version) { "1.0.0" }
 
       it "returns an empty list" do
-        expect(blocking_parent_dependencies).to eq([])
+        expect(conflicting_dependencies).to eq([])
       end
     end
   end
diff --git a/common/lib/dependabot/update_checkers/base.rb b/common/lib/dependabot/update_checkers/base.rb
index 1491decc3c..a0d03e449f 100644
--- a/common/lib/dependabot/update_checkers/base.rb
+++ b/common/lib/dependabot/update_checkers/base.rb
@@ -99,7 +99,7 @@ def latest_resolvable_version_with_no_unlock
       #   name [String] the blocking dependencies name
       #   version [String] the version of the blocking dependency
       #   requirement [String] the requirement on the target_dependency
-      def blocking_parent_dependencies
+      def conflicting_dependencies
         [] # return an empty array for ecosystems that don't support this yet
       end
 

From f8a4f1fd0a4c9b6b5a13de84b2a44eb3b3a5e9f7 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 15:55:15 +0100
Subject: [PATCH 12/13] Improve conflicting dependencies code in dry-run script

---
 bin/dry-run.rb | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/bin/dry-run.rb b/bin/dry-run.rb
index e31b2fb18e..78efd310a0 100755
--- a/bin/dry-run.rb
+++ b/bin/dry-run.rb
@@ -489,14 +489,16 @@ def security_fix?(dependency)
                            end
   puts " => latest allowed version is #{latest_allowed_version || dep.version}"
 
-  parents = checker.conflicting_dependencies
-  if parents.any?
+  conflicting_dependencies = checker.conflicting_dependencies
+  if conflicting_dependencies.any?
     puts " => The update is not possible because of the following conflicting "\
       "dependencies:"
-  end
-  parents.each do |parent|
-    puts "   #{parent['name']} (#{parent['version']}) which requires:"
-    puts "     #{dep.name} #{parent['requirement']}"
+
+    conflicting_dependencies.each do |conflicting_dep|
+      puts "   #{conflicting_dep['name']} (#{conflicting_dep['version']}) "\
+        "which requires:"
+      puts "     #{dep.name} #{conflicting_dep['requirement']}"
+    end
   end
 
   if checker.up_to_date?

From 2e50b1dfee7777b7b56097289dae2d4a31112177 Mon Sep 17 00:00:00 2001
From: jurre <jurre@github.com>
Date: Wed, 4 Nov 2020 17:15:13 +0100
Subject: [PATCH 13/13] Fix string keys in ConflictingDependencyResolver spec

---
 .../functions/conflicting_dependency_resolver_spec.rb     | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/bundler/spec/native_helpers/functions/conflicting_dependency_resolver_spec.rb b/bundler/spec/native_helpers/functions/conflicting_dependency_resolver_spec.rb
index 09320b0ae2..dbb3d944ea 100644
--- a/bundler/spec/native_helpers/functions/conflicting_dependency_resolver_spec.rb
+++ b/bundler/spec/native_helpers/functions/conflicting_dependency_resolver_spec.rb
@@ -27,9 +27,11 @@
 
     it "returns a list of dependencies that block the update" do
       expect(conflicting_dependencies).to eq(
-        [
-          { name: "dummy-pkg-b", version: "1.0.0", requirement: "< 2.0.0" }
-        ]
+        [{
+          "name" => "dummy-pkg-b",
+          "version" => "1.0.0",
+          "requirement" => "< 2.0.0"
+        }]
       )
     end