fix: meta["partial-data"] might be empty

README.md

@@ -57,9 +57,9 @@ partial-data:
 > Or used inline: To you I say "{{< partial _hello.md >}}"
 > ```
 >
-> Hello, friend!
+> Hello, !
 >
-> Or used inline: To you I say “Hello, friend!”
+> Or used inline: To you I say “Hello, !”
 
 Alternatively, the second argument of the shortcode can point to a
 custom key in your YAML frontmatter, e.g.
@@ -74,7 +74,7 @@ my-data:
 > {{< partial _hello.md my-data.friends >}}
 > ```
 >
-> Hello, amigo!
+> Hello, !
 
 Another, possibly less convenient, option is to provide JSON in the
 shortcode data. Any key-value pair that starts with `{` or `[` will be

_extensions/partials/quarto-partials.lua

@@ -123,18 +123,20 @@ local function quarto_partial(args, kwargs, meta, raw_args, context)
         assert(false, msg)
       end
     end
-  else
+  elseif meta[partial_key] then
     partial_data = copy(meta[partial_key])
   end
 
-  local data_str = pandoc_stringify(partial_data)
+  if #partial_data > 0 then
+    local data_str = pandoc_stringify(partial_data)
 
-  if type(data_str) == "string" then
-    quarto.log.error("Please choose a metadata key from your YAML frontmatter that contains a table of partial data.")
-    assert(false, "Expected a table of partial data in YAML frontmatter key " .. partial_key)
-  end
+    if type(data_str) == "string" then
+      quarto.log.error("Please choose a metadata key from your YAML frontmatter that contains a table of partial data.")
+      assert(false, "Expected a table of partial data in YAML frontmatter key " .. partial_key)
+    end
 
-  data = data_str
+    data = data_str
+  end
 
   for k, v in pairs(kwargs) do
     local v_is_json_string = false