buildmimetree.py: externalise file i/o from converter

diff --git a/.config/neomutt/buildmimetree.py b/.config/neomutt/buildmimetree.py
index 57fc21a3ced7e6f72c99d6e569caf7dcd7238536..894216f5486a8ca1d2207721bd3b6109ae1718da 100755 (executable)
--- a/.config/neomutt/buildmimetree.py
+++ b/.config/neomutt/buildmimetree.py
@@ -140,26 +140,29 @@ class Multipart(
         return f"<multipart/{self.subtype}> children={len(self.children)}"
 
 
-def convert_markdown_to_html(maildraft, *, extensions=None):
-    draftpath = pathlib.Path(maildraft)
-    with open(draftpath, "r", encoding="utf-8") as textmarkdown:
-        text = textmarkdown.read()
 
+def convert_markdown_to_html(
+    origtext, draftpath, *, filewriter_fn=None, extensions=None
+):
     mdwn = markdown.Markdown(extensions=extensions)
 
+    if not filewriter_fn:
+
+        def filewriter_fn(path, content, mode="w", **kwargs):
+            with open(path, mode, **kwargs) as out_f:
+                out_f.write(content)
 
-    with open(draftpath, "w", encoding="utf-8") as textplain:
-        textplain.write(text)
+    filewriter_fn(draftpath, origtext, encoding="utf-8")
     textpart = Part(
         "text", "plain", draftpath, "Plain-text version", orig=True
     )
 
-    html = mdwn.convert(text)
+    htmltext = mdwn.convert(origtext)
+
     htmlpath = draftpath.with_suffix(".html")
-    with open(
-        htmlpath, "w", encoding="utf-8", errors="xmlcharrefreplace"
-    ) as texthtml:
-        texthtml.write(html)
+    filewriter_fn(
+        htmlpath, htmltext, encoding="utf-8", errors="xmlcharrefreplace"
+    )
     htmlpart = Part("text", "html", htmlpath, "HTML version")
 
     logopart = Part(
@@ -339,7 +342,10 @@ def do_massage(
     cmds.flush()
 
     extensions = extensions.split(",") if extensions else []
-    tree = converter(maildraft, extensions=extensions)
+    with open(maildraft, "r") as draft_f:
+        tree = converter(
+            draft_f.read(), pathlib.Path(maildraft), extensions=extensions
+        )
 
     mimetree = MIMETreeDFWalker(debug=debug_walk)