Merge pull request #1680 from opensafely-core/csv-download-headers

Respect fixed_headers for non-dm+d codelist downloads

codelists/models.py

@@ -530,9 +530,23 @@ def _new_style_codes(self):
         return tuple(sorted(self.codeset.codes()))
 
     def csv_data_for_download(self, fixed_headers=False, include_mapped_vmps=True):
-        fixed_headers = fixed_headers or include_mapped_vmps
+        """
+        Prepare codes for download.  If this is a new-style codelists, the csv data with
+        code and related term will be built from the code objects, looking up the terms in
+        the coding system.  If it is an old-style codelist, it has no associated code objects,
+        and it will use the uploaded csv_data.
+
+        include_mapped_vmps: if True, a dm+d codelist will include mapped VMPs in its download.
+          This value defaults to True, so that when these downloads are requested by OpenSafely CLI,
+          no additional query params need to be passed that are specidfic to dm+d codelists.
+        fixed_headers: if True, uploaded csv_data is converted to two columns, headed "code" and "term".
+          This parameter is ignored for dmd downloads that include mapped VMPs
+        """
         if self.csv_data:
-            if not fixed_headers:
+            dmd_with_mapped_vmps = (
+                self.coding_system_id == "dmd" and include_mapped_vmps
+            )
+            if not fixed_headers and not dmd_with_mapped_vmps:
                 return self.csv_data
             table = self.table_with_fixed_headers(include_mapped_vmps)
         else:

codelists/tests/views/test_version_download.py

@@ -8,11 +8,15 @@ def test_get(client, version):
     assert data == version.csv_data_for_download()
 
 
+def test_get_with_original_headers(client, old_style_version):
+    # by default, the original csv data is downloaded
+    rsp = client.get(old_style_version.get_download_url())
+    data = rsp.content.decode("utf8")
+    assert data == old_style_version.csv_data_for_download()
+    assert csv_data_to_rows(data)[0] == ["code", "name"]
+
+
 def test_get_with_fixed_headers(client, old_style_version):
-    old_style_version.csv_data = old_style_version.csv_data.replace(
-        "id,name", "code,name"
-    )
-    old_style_version.save()
     assert old_style_version.table[0] == ["code", "name"]
     rsp = client.get(old_style_version.get_download_url() + "?fixed-headers")
     data = rsp.content.decode("utf8")