Param requires_python is optional for pypi

Make the requires_python optional for the pypi
upload endpoint to conform with pypi standards.

Changelog: fixed

app/models/packages/pypi/metadatum.rb

@@ -6,7 +6,7 @@ class Packages::Pypi::Metadatum < ApplicationRecord
   belongs_to :package, -> { where(package_type: :pypi) }, inverse_of: :pypi_metadatum
 
   validates :package, presence: true
-  validates :required_python, length: { maximum: 255 }, allow_blank: true
+  validates :required_python, length: { maximum: 255 }, allow_nil: false
 
   validate :pypi_package_type
 

app/services/packages/pypi/create_package_service.rb

@@ -9,7 +9,7 @@ module Packages
         ::Packages::Package.transaction do
           meta = Packages::Pypi::Metadatum.new(
             package: created_package,
-            required_python: params[:requires_python]
+            required_python: params[:requires_python] || ''
           )
 
           unless meta.valid?

db/migrate/20220304152729_add_default_to_required_python_on_packages_pypi_metadata.rb

+# frozen_string_literal: true
+
+class AddDefaultToRequiredPythonOnPackagesPypiMetadata < Gitlab::Database::Migration[1.0]
+  def up
+    change_column_default(:packages_pypi_metadata, :required_python, '')
+  end
+
+  def down
+    change_column_default(:packages_pypi_metadata, :required_python, nil)
+  end
+end

db/schema_migrations/20220304152729

+483f8299688a6e24fa77867b7dab8a2dad0c2b7ebe43c56c81c02ab1e0dc4674
\ No newline at end of file

db/structure.sql

@@ -18322,7 +18322,7 @@ ALTER SEQUENCE packages_packages_id_seq OWNED BY packages_packages.id;
 
 CREATE TABLE packages_pypi_metadata (
     package_id bigint NOT NULL,
-    required_python text,
+    required_python text DEFAULT ''::text,
     CONSTRAINT check_0d9aed55b2 CHECK ((required_python IS NOT NULL)),
     CONSTRAINT check_379019d5da CHECK ((char_length(required_python) <= 255))
 );

doc/api/packages/pypi.md

@@ -175,6 +175,7 @@ PUT projects/:id/packages/pypi
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
 | `id`      | string | yes | The ID or full path of the project. |
+| `requires_python` | string | no | The PyPI required version. |
 
 ```shell
 curl --request PUT \

lib/api/pypi_packages.rb

@@ -170,9 +170,9 @@ module API
 
         params do
           requires :content, type: ::API::Validations::Types::WorkhorseFile, desc: 'The package file to be published (generated by Multipart middleware)'
-          requires :requires_python, type: String
           requires :name, type: String
           requires :version, type: String
+          optional :requires_python, type: String
           optional :md5_digest, type: String
           optional :sha256_digest, type: String
         end

spec/models/packages/pypi/metadatum_spec.rb

@@ -8,6 +8,9 @@ RSpec.describe Packages::Pypi::Metadatum, type: :model do
 
   describe 'validations' do
     it { is_expected.to validate_presence_of(:package) }
+    it { is_expected.to allow_value('').for(:required_python) }
+    it { is_expected.not_to allow_value(nil).for(:required_python) }
+    it { is_expected.not_to allow_value('a' * 256).for(:required_python) }
 
     describe '#pypi_package_type' do
       it 'will not allow a package with a different package_type' do

spec/requests/api/pypi_packages_spec.rb

@@ -185,6 +185,14 @@ RSpec.describe API::PypiPackages do
 
         it_behaves_like params[:shared_examples_name], params[:user_role], params[:expected_status], params[:member]
       end
+
+      context 'without requires_python' do
+        let(:token) { personal_access_token.token }
+        let(:user_headers) { basic_auth_header(user.username, token) }
+        let(:headers) { user_headers.merge(workhorse_headers) }
+
+        it_behaves_like 'PyPI package creation', :developer, :created, true
+      end
     end
 
     context 'with required_python too big' do

spec/services/packages/pypi/create_package_service_spec.rb

 # frozen_string_literal: true
 require 'spec_helper'
 
-RSpec.describe Packages::Pypi::CreatePackageService do
+RSpec.describe Packages::Pypi::CreatePackageService, :aggregate_failures do
   include PackagesManagerApiSpecHelpers
 
   let_it_be(:project) { create(:project) }
@@ -39,6 +39,18 @@ RSpec.describe Packages::Pypi::CreatePackageService do
       end
     end
 
+    context 'without required_python' do
+      before do
+        params.delete(:requires_python)
+      end
+
+      it 'creates the package' do
+        expect { subject }.to change { Packages::Package.pypi.count }.by(1)
+
+        expect(created_package.pypi_metadatum.required_python).to eq ''
+      end
+    end
+
     context 'with an invalid metadata' do
       let(:requires_python) { 'x' * 256 }
 
@@ -73,7 +85,7 @@ RSpec.describe Packages::Pypi::CreatePackageService do
             .and raise_error(/File name has already been taken/)
         end
 
-        context 'with a pending_destruction package', :aggregate_failures do
+        context 'with a pending_destruction package' do
           before do
             Packages::Package.pypi.last.pending_destruction!
           end