No newline at end of metadata file causes misparsing of raw block

[iandol]

Explain the problem.

See https://groups.google.com/g/pandoc-discuss/c/FT_hz4lbNnA for context.

Use this metadata file (I tested with backticks but this causes problems in github so here I replace backticks with tildes; make sure no newline after end of raw block):

header-includes: |
  ~~~{=typst}
  #set heading(numbering: "«I»")
  #set text(font: "Alegreya Sans", size: 14pt, discretionary-ligatures: true, number-type: "old-style")
  ~~~

Now call pandoc with this file (type something into STDIN)

pandoc -s --metadata-file test.yaml -t typst --verbose
# Title

Some text.

[CTRL+D]

output...

`{=typst} #set heading(numbering: "«I»") #set text(font: "Alegreya Sans", size: 14pt, discretionary-ligatures: true, number-type: "old-style")`

= Title
<title>
Some text.

Note the header-include is malformed. Now add a newline in the metadata file:

header-includes: |
  ~~~{=typst}
  #set heading(numbering: "«I»")
  #set text(font: "Alegreya Sans", size: 14pt, discretionary-ligatures: true, number-type: "old-style")
  ~~~
  

And now the raw block gets output properly:

    #set heading(numbering: "«I»")
    #set text(font: "Alegreya Sans", size: 14pt, discretionary-ligatures: true, number-type: "old-style")
    
    
    = Title
    <title>
    Some text.

Honestly, I don't understand the YAML spec well enough to know if this is expected or not:

https://yaml.org/spec/1.2.2/#812-literal-style

The default block chomping is apparently clip: https://yaml.org/spec/1.2.2/#8112-block-chomping-indicator — but any setting (e.g. +) doesn't impact this behaviour in Pandoc...

[jgm]

Oh, I see -- you had a text file that didn't end in a newline?

[iandol]

Yes, I ended up with a separate metadata file as I couldn't get the header-includes to work added to the defaults file directly. Note if it is a raw inline then it works:

header-includes: |
  `#set heading(numbering: "«I»")`{=typst}

Test:

▷ pandoc -s --metadata-file test.yaml -t typst --verbose
# Title

Some text.

[CTRL+D]

...

#set heading(numbering: "«I»")


= Title
<title>
Some text.

So the lack of newline only affects raw blocks not raw inlines (which makes some sense).

[jgm]

Text files canonically are supposed to end with a newline; lots of things break if they don't.

[iandol]

Ok, as this is already a bit of an edge case, I'll close it...