error in parser when string to parse is \nclassDiagram

[ittayd]

Describe the bug
I'm using mermaid 9.1.3 through the TiddlyWiki plugin (that I updated to use 9.1.3).

This works:

<$mermaid text='
sequenceDiagram
'/>

It renders an empty sequence diagram

This, however, doesn't:

<$mermaid text='
classDiagram
  A <|-- B
'/>

The error is:

Error: Parse error on line 1:
classDiagram A <|
^
Expecting 'statments', 'direction_tb', 'direction_bt', 'direction_rl', 'direction_lr', 'open_directive', 'CLASS_DIAGRAM', got 'NEWLINE'

This works:

<$mermaid text='classDiagram
  A <|-- B
'/>

The difference is that the bad code passes '\nclassDiagram..' to the parser while the good one passes 'classDiagram...'. The initial newline is parsed fine for sequence diagrams.

Note also that this doesn't work

<$mermaid text='classDiagram
'/>

With the error

Error: Parse error on line 2:
classDiagram
------------^
Expecting 'direction_tb', 'direction_bt', 'direction_rl', 'direction_lr', 'open_directive', 'acc_title', 'acc_descr', 'acc_descr_multiline_value', 'CLASS', 'ANNOTATION_START', 'MEMBER', 'SEPARATOR', 'CALLBACK', 'LINK', 'CLICK', 'CSSCLASS', 'UNICODE_TEXT', 'NUM', 'ALPHA', 'BQUOTE_STR', got 'EOF'

nor this
<$mermaid text='classDiagram'/>

The error is:

Error: Parse error on line 1:
classDiagram
------------^
Expecting 'NEWLINE', got 'EOF'

passing 'sequenceDiagram' instead of 'classDiagram' in the above creates an empty sequence diagram.

Expected behavior
Handle leading and trailing newlines

[knsv]

I think there is some characters picked up by the plugin as I can not reproduce the issue. Neither in the live editor or a local html file.

[knsv]

Added a unit test and could reproduce the issue that way. We will plan a fix.