Parse method does not return a boolean

Describe the bug The mermaid.parse() method is supposed to return a boolean when passed a string of mermaid markdown, but it is instead returning undefined for valid markup, and an Uncaught error on invalid markup.

To Reproduce mermaid.parse('graph TD\n') = returns undefined mermaid.parse('graph TD\n{') = returns Uncaught {str: "Parse error on line 1...

Expected behavior Per this section of the current documentation,

“The function mermaid.parse(txt) takes a text string as an argument and returns true if the text is syntactically correct and false if it is not.”

mermaid.parse('graph TD\n') = should return true mermaid.parse('graph TD\n{') = should return false

Screenshots

Desktop (please complete the following information):

• OS: Windows 10 Pro
• Browser: Chrome
• Version: 77.0.3865.120

[klemmchr]

You’re right, I also consider that to be a flaw in the docs. I like the idea of a separate method, that could be handy. Will implement that.

[klemmchr]

Still the parse function would throw an exception (because removing that would be a breaking change). Regarding execution flow, it would stop if you don’t catch the exception. And if you catch it, you automatically know that the parser failed. Imo that’s a suitable solution that would also fit the code you posted (if you change it a bit).