From 836c54b3d270652295c5775ea8e37f13ecdadfdb Mon Sep 17 00:00:00 2001
From: Jeremy Gonzalez <jeremy@fossa.com>
Date: Thu, 15 Aug 2024 16:11:30 -0600
Subject: [PATCH] field is optional

---
 src/Strategy/Python/Poetry/Common.hs    | 2 +-
 src/Strategy/Python/Poetry/PyProject.hs | 4 ++--
 test/Python/Poetry/CommonSpec.hs        | 2 +-
 test/Python/Poetry/PyProjectSpec.hs     | 4 ++--
 test/Python/PoetrySpec.hs               | 2 +-
 5 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/Strategy/Python/Poetry/Common.hs b/src/Strategy/Python/Poetry/Common.hs
index 0e38ed8d5b..7aa23ad55d 100644
--- a/src/Strategy/Python/Poetry/Common.hs
+++ b/src/Strategy/Python/Poetry/Common.hs
@@ -44,7 +44,7 @@ import Strategy.Python.Poetry.PyProject (
 
 -- | Gets build backend of pyproject.
 getPoetryBuildBackend :: PyProject -> Maybe Text
-getPoetryBuildBackend project = buildBackend <$> pyprojectBuildSystem project
+getPoetryBuildBackend project = buildBackend =<< pyprojectBuildSystem project
 
 -- | Supported pyproject dependencies.
 supportedPyProjectDep :: PoetryDependency -> Bool
diff --git a/src/Strategy/Python/Poetry/PyProject.hs b/src/Strategy/Python/Poetry/PyProject.hs
index 0ee0714c80..29bb2e5aff 100644
--- a/src/Strategy/Python/Poetry/PyProject.hs
+++ b/src/Strategy/Python/Poetry/PyProject.hs
@@ -126,7 +126,7 @@ data PyProjectMetadata = PyProjectMetadata
   deriving (Show, Eq, Ord)
 
 newtype PyProjectBuildSystem = PyProjectBuildSystem
-  { buildBackend :: Text
+  { buildBackend :: Maybe Text
   }
   deriving (Show, Eq, Ord)
 
@@ -134,7 +134,7 @@ instance Toml.Schema.FromValue PyProjectBuildSystem where
   fromValue =
     Toml.Schema.parseTableFromValue $
       PyProjectBuildSystem
-        <$> Toml.Schema.reqKey "build-backend"
+        <$> Toml.Schema.optKey "build-backend"
 
 data PyProjectPoetry = PyProjectPoetry
   { name :: Maybe Text
diff --git a/test/Python/Poetry/CommonSpec.hs b/test/Python/Poetry/CommonSpec.hs
index 27c89a8168..01d80a330a 100644
--- a/test/Python/Poetry/CommonSpec.hs
+++ b/test/Python/Poetry/CommonSpec.hs
@@ -40,7 +40,7 @@ import Toml.Schema qualified
 expectedPyProject :: PyProject
 expectedPyProject =
   PyProject
-    { pyprojectBuildSystem = Just $ PyProjectBuildSystem{buildBackend = "poetry.core.masonry.api"}
+    { pyprojectBuildSystem = Just $ PyProjectBuildSystem{buildBackend = Just "poetry.core.masonry.api"}
     , pyprojectProject = Nothing
     , pyprojectTool =
         Just $
diff --git a/test/Python/Poetry/PyProjectSpec.hs b/test/Python/Poetry/PyProjectSpec.hs
index 600f7894aa..cd7479c09c 100644
--- a/test/Python/Poetry/PyProjectSpec.hs
+++ b/test/Python/Poetry/PyProjectSpec.hs
@@ -54,7 +54,7 @@ shouldParseInto = parseMatch parseConstraintExpr
 expectedPyProject :: PyProject
 expectedPyProject =
   PyProject
-    { pyprojectBuildSystem = Just $ PyProjectBuildSystem{buildBackend = "poetry.core.masonry.api"}
+    { pyprojectBuildSystem = Just $ PyProjectBuildSystem{buildBackend = Just "poetry.core.masonry.api"}
     , pyprojectProject = Nothing
     , pyprojectTool =
         Just $
@@ -90,7 +90,7 @@ expectedPyProject =
 expectedPyProject3 :: PyProject
 expectedPyProject3 =
   PyProject
-    { pyprojectBuildSystem = Just $ PyProjectBuildSystem{buildBackend = "poetry.core.masonry.api"}
+    { pyprojectBuildSystem = Just $ PyProjectBuildSystem{buildBackend = Just "poetry.core.masonry.api"}
     , pyprojectProject = Nothing
     , pyprojectTool =
         Just $
diff --git a/test/Python/PoetrySpec.hs b/test/Python/PoetrySpec.hs
index 7633ed63de..78ea41a853 100644
--- a/test/Python/PoetrySpec.hs
+++ b/test/Python/PoetrySpec.hs
@@ -39,7 +39,7 @@ newPoetryLock pkgs = PoetryLock pkgs $ PoetryMetadata "some-version" "some-hash"
 candidatePyProject :: PyProject
 candidatePyProject =
   PyProject
-    { pyprojectBuildSystem = Just $ PyProjectBuildSystem "poetry.core.masonry.api"
+    { pyprojectBuildSystem = Just $ PyProjectBuildSystem{buildBackend = Just "poetry.core.masonry.api"}
     , pyprojectProject = Nothing
     , pyprojectTool =
         Just $