Preserve order of dependencies when deduping

Author: cpsievert

htmltools/_core.py

@@ -1215,19 +1215,24 @@ def _static_extract_serialized_html_deps(
         # HTMLdependency.get_tag_representation()
         pattern = r'<script type="application/json" data-html-dependency="">((?:.|\r|\n)*?)</script>'
         dep_strs = re.findall(pattern, html)
-        # Deduplicate dependencies. htmltools normally would dedupe dependencies, but
-        # with HTMLTextDocuments, the input HTML would usually have been generated by
-        # something else (like Quarto) and may not have the dependencies deduped.
-        dep_strs = list(set(dep_strs))
 
         # Remove the serialized HTML dependencies from the HTML string
         html = re.sub(pattern, "", html)
 
+        # Reconstitute the HTMLDependency objects
+        #
+        # Note: htmltools normally would dedupe dependencies, but
+        # with HTMLTextDocuments, the input HTML would usually have been generated by
+        # something else (like Quarto) and may not have the dependencies deduped.
+        seen_deps: set[str] = set()
         deps: list[HTMLDependency] = []
         for dep_str in dep_strs:
+            if dep_str in seen_deps:
+                continue
             args = json.loads(dep_str)
             dep = HTMLDependency(**args)
             deps.append(dep)
+            seen_deps.add(dep_str)
 
         return (html, deps)