Centralize pyenv install logic

python/lib/dependabot/python/file_updater/pip_compile_file_updater.rb

@@ -7,6 +7,7 @@
 require "dependabot/python/file_parser/python_requirement_parser"
 require "dependabot/python/file_updater"
 require "dependabot/shared_helpers"
+require "dependabot/python/helpers"
 require "dependabot/python/native_helpers"
 require "dependabot/python/python_versions"
 require "dependabot/python/name_normaliser"
@@ -65,7 +66,7 @@ def fetch_updated_dependency_files
         def compile_new_requirement_files
           SharedHelpers.in_a_temporary_directory do
             write_updated_dependency_files
-            install_required_python
+            Helpers.install_required_python(python_version)
 
             filenames_to_compile.each do |filename|
               # Shell out to pip-compile, generate a new set of requirements.
@@ -212,16 +213,6 @@ def write_updated_dependency_files
           end
         end
 
-        def install_required_python
-          # The leading space is important
-          return if run_command("pyenv versions").include?(" #{python_version}")
-
-          run_command("pyenv install -s #{python_version}")
-          run_command("pyenv exec pip install --upgrade pip")
-          run_command("pyenv exec pip install -r " \
-                      "#{NativeHelpers.python_requirements_path}")
-        end
-
         def sanitized_setup_file_content(file)
           @sanitized_setup_file_content ||= {}
           return @sanitized_setup_file_content[file.name] if @sanitized_setup_file_content[file.name]

python/lib/dependabot/python/file_updater/pipfile_file_updater.rb

@@ -302,11 +302,7 @@ def install_required_python
             nil
           end
 
-          return if run_command("pyenv versions").include?("#{python_version}\n")
-
-          requirements_path = NativeHelpers.python_requirements_path
-          run_command("pyenv install -s #{python_version}")
-          run_command("pyenv exec pip install -r #{requirements_path}")
+          Helpers.install_required_python(python_version)
         end
 
         def sanitized_setup_file_content(file)

python/lib/dependabot/python/file_updater/poetry_file_updater.rb

@@ -4,6 +4,7 @@
 require "open3"
 require "dependabot/dependency"
 require "dependabot/shared_helpers"
+require "dependabot/python/helpers"
 require "dependabot/python/version"
 require "dependabot/python/requirement"
 require "dependabot/python/python_versions"
@@ -170,12 +171,7 @@ def updated_lockfile_content_for(pyproject_content)
               write_temporary_dependency_files(pyproject_content)
               add_auth_env_vars
 
-              if python_version && !pre_installed_python?(python_version)
-                run_poetry_command("pyenv install -s #{python_version}")
-                run_poetry_command("pyenv exec pip install --upgrade pip")
-                run_poetry_command("pyenv exec pip install -r" \
-                                   "#{NativeHelpers.python_requirements_path}")
-              end
+              Helpers.install_required_python(python_version)
 
               # use system git instead of the pure Python dulwich
               unless python_version&.start_with?("3.6")

python/lib/dependabot/python/helpers.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+require "dependabot/logger"
+
+module Dependabot
+  module Python
+    module Helpers
+      def self.install_required_python(python_version)
+        # The leading space is important in the version check
+        return if SharedHelpers.run_shell_command("pyenv versions").include?(" #{python_version}")
+
+        Dependabot.logger.info("Installing required Python #{python_version}.")
+        SharedHelpers.run_shell_command("pyenv install -s #{python_version}")
+        SharedHelpers.run_shell_command("pyenv exec pip install --upgrade pip")
+        SharedHelpers.run_shell_command("pyenv exec pip install -r" \
+                                        "#{NativeHelpers.python_requirements_path}")
+      end
+    end
+  end
+end

python/lib/dependabot/python/update_checker/pip_compile_version_resolver.rb

@@ -11,6 +11,7 @@
 require "dependabot/python/file_updater/setup_file_sanitizer"
 require "dependabot/python/version"
 require "dependabot/shared_helpers"
+require "dependabot/python/helpers"
 require "dependabot/python/native_helpers"
 require "dependabot/python/python_versions"
 require "dependabot/python/name_normaliser"
@@ -70,7 +71,7 @@ def fetch_latest_resolvable_version_string(requirement:)
             SharedHelpers.in_a_temporary_directory do
               SharedHelpers.with_git_configured(credentials: credentials) do
                 write_temporary_dependency_files(updated_req: requirement)
-                install_required_python
+                Helpers.install_required_python(python_version)
 
                 filenames_to_compile.each do |filename|
                   # Shell out to pip-compile.
@@ -319,16 +320,6 @@ def write_original_manifest_files
           end
         end
 
-        def install_required_python
-          # The leading space is important
-          return if run_command("pyenv versions").include?(" #{python_version}")
-
-          run_command("pyenv install -s #{python_version}")
-          run_command("pyenv exec pip install --upgrade pip")
-          run_command("pyenv exec pip install -r" \
-                      "#{NativeHelpers.python_requirements_path}")
-        end
-
         def sanitized_setup_file_content(file)
           @sanitized_setup_file_content ||= {}
           return @sanitized_setup_file_content[file.name] if @sanitized_setup_file_content[file.name]

python/lib/dependabot/python/update_checker/pipenv_version_resolver.rb

@@ -320,14 +320,7 @@ def install_required_python
             nil
           end
 
-          # The leading space is important
-          return if run_command("pyenv versions").include?(" #{python_version}")
-
-          requirements_path = NativeHelpers.python_requirements_path
-          run_command("pyenv install -s #{python_version}")
-          run_command("pyenv exec pip install --upgrade pip")
-          run_command("pyenv exec pip install -r " \
-                      "#{requirements_path}")
+          Helpers.install_required_python(python_version)
         end
 
         def sanitized_setup_file_content(file)

python/lib/dependabot/python/update_checker/poetry_version_resolver.rb

@@ -82,7 +82,6 @@ def resolvable?(version:)
 
         private
 
-        # rubocop:disable Metrics/PerceivedComplexity
         def fetch_latest_resolvable_version_string(requirement:)
           @latest_resolvable_version_string ||= {}
           return @latest_resolvable_version_string[requirement] if @latest_resolvable_version_string.key?(requirement)
@@ -93,14 +92,7 @@ def fetch_latest_resolvable_version_string(requirement:)
                 write_temporary_dependency_files(updated_req: requirement)
                 add_auth_env_vars
 
-                if python_version && !pre_installed_python?(python_version)
-                  run_poetry_command("pyenv install -s #{python_version}")
-                  run_poetry_command("pyenv exec pip install --upgrade pip")
-                  run_poetry_command(
-                    "pyenv exec pip install -r " \
-                    "#{NativeHelpers.python_requirements_path}"
-                  )
-                end
+                Helpers.install_required_python(python_version)
 
                 # use system git instead of the pure Python dulwich
                 unless python_version&.start_with?("3.6")
@@ -123,7 +115,6 @@ def fetch_latest_resolvable_version_string(requirement:)
               end
             end
         end
-        # rubocop:enable Metrics/PerceivedComplexity
 
         def fetch_version_from_parsed_lockfile(updated_lockfile)
           version =
@@ -346,7 +337,7 @@ def run_poetry_command(command)
           stdout, process = Open3.capture2e(command)
           time_taken = Time.now - start
 
-          # Raise an error with the output from the shell session if Pipenv
+          # Raise an error with the output from the shell session if poetry
           # returns a non-zero status
           return if process.success?