From 83e24ec36f7c7a1796216d34f4ecfaee7d9eb97c Mon Sep 17 00:00:00 2001
From: James Crake-Merani <james.crake-merani@stfc.ac.uk>
Date: Fri, 9 Oct 2026 10:40:01 +0100
Subject: [PATCH 1/4] Static method to initialise empty metadata.

---
 sasdata/metadata.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/sasdata/metadata.py b/sasdata/metadata.py
index 1ad46b93..7a7084c7 100644
--- a/sasdata/metadata.py
+++ b/sasdata/metadata.py
@@ -622,6 +622,19 @@ def from_json(obj):
             raw=MetaNode.from_json(obj["raw"]),
         )
 
+    @staticmethod
+    def initialise_empty():
+        return Metadata(
+            title=None,
+            run=[],
+            definition=None,
+            process=[],
+            sample=None,
+            instrument=None,
+            magnetic=None,
+            raw=None
+        )
+
     def serialise_json(self):
         serialized = {
             "instrument": None,

From b33f75755799b708cbc5bc8c4b9aedac5117c39a Mon Sep 17 00:00:00 2001
From: James Crake-Merani <james.crake-merani@stfc.ac.uk>
Date: Fri, 9 Oct 2026 10:43:13 +0100
Subject: [PATCH 2/4] Don't require Metadata on instantiation.

SasData, and SasMeasurement no longer require metadata to be provided
for instantiation. If none is provided, they will just init empty metadata.
---
 sasdata/data.py | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/sasdata/data.py b/sasdata/data.py
index a9cd9648..b6f17df0 100644
--- a/sasdata/data.py
+++ b/sasdata/data.py
@@ -23,14 +23,17 @@ def __init__(
         abscissae: Abscissa,
         mask: Quantity,
         dependents: list["SasData"],
-        metadata: Metadata,
+        metadata: Metadata | None = None,
     ):
         self.name = name
         self._ordinate = ordinate
         self._abscissae = abscissae
         self._mask = mask
         self.dependents = dependents
-        self.metadata = metadata
+        if self.metadata:
+            self.metadata = metadata
+        else:
+            self.metadata = Metadata.initialise_empty()
 
     @property
     def ordinate(self) -> Quantity:
@@ -72,7 +75,7 @@ def __init__(
         name: str,
         data_contents: dict[str, Quantity],
         dataset_type: DatasetType,
-        metadata: Metadata,
+        metadata: Metadata | None = None,
         verbose: bool = False,
     ):
         self.name = name
@@ -82,7 +85,11 @@ def __init__(
         self._data_contents = data_contents
         self._verbose = verbose
 
-        self.metadata = metadata
+        if self.metadata:
+            self.metadata = metadata
+        else:
+            self.metadata = Metadata.initialise_empty()
+            
 
         # TODO: Could this be optional?
         self.dataset_type: DatasetType = dataset_type

From 2fd982d95092a409b4f6dc5bafbd992ae2d28fa0 Mon Sep 17 00:00:00 2001
From: James Crake-Merani <james.crake-merani@stfc.ac.uk>
Date: Fri, 9 Oct 2026 10:46:32 +0100
Subject: [PATCH 3/4] Don't check self.metadata before its been set.

Tests were failing because of this.
---
 sasdata/data.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sasdata/data.py b/sasdata/data.py
index b6f17df0..380e471d 100644
--- a/sasdata/data.py
+++ b/sasdata/data.py
@@ -30,7 +30,7 @@ def __init__(
         self._abscissae = abscissae
         self._mask = mask
         self.dependents = dependents
-        if self.metadata:
+        if metadata:
             self.metadata = metadata
         else:
             self.metadata = Metadata.initialise_empty()
@@ -85,7 +85,7 @@ def __init__(
         self._data_contents = data_contents
         self._verbose = verbose
 
-        if self.metadata:
+        if metadata:
             self.metadata = metadata
         else:
             self.metadata = Metadata.initialise_empty()

From e49b7438e43340dd09e72adeec7a55a67fd83a6e Mon Sep 17 00:00:00 2001
From: "pre-commit-ci-lite[bot]"
 <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
Date: Fri, 9 Oct 2026 09:49:36 +0000
Subject: [PATCH 4/4] [pre-commit.ci lite] apply automatic fixes for ruff
 linting errors

---
 sasdata/data.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sasdata/data.py b/sasdata/data.py
index 380e471d..cb96b33d 100644
--- a/sasdata/data.py
+++ b/sasdata/data.py
@@ -89,7 +89,7 @@ def __init__(
             self.metadata = metadata
         else:
             self.metadata = Metadata.initialise_empty()
-            
+
 
         # TODO: Could this be optional?
         self.dataset_type: DatasetType = dataset_type