Throw error if mermaid rendering fails

[aloisklink]

📑 Summary

Throws an error if mermaid rendering fails. If there is an error:

• mermaid-cli exits with exitcode 1.
• The errors are logged to stderr (console.error).
• Changed Behaviour: If there is an error, there is no output file. Previously there was an output file that said "Syntax error in graph: mermaid version 9.1.2" (e.g.: mermaid-error.png)

Resolves #276, resolves #245, resolves #138, resolves #109

Example:

me@me:~/mermaid-cli$ node index.bundle.js -i test-negative/invalid.expect-error.mmd -o test-output/invalid.expect-error.svg -c test-positive/config.json
Generating single mermaid chart

Parse error on line 2:
...nceDiagram  Nothing:Valid
----------------------^
Expecting 'SOLID_OPEN_ARROW', 'DOTTED_OPEN_ARROW', 'SOLID_ARROW', 'DOTTED_ARROW', 'SOLID_CROSS', 'DOTTED_CROSS', 'SOLID_POINT', 'DOTTED_POINT', got 'TXT'
me@me:~/mermaid-cli$ echo $?
1

📏 Design Decisions

Uses the new initThrowsError from Mermaid that was added in mermaid-js/mermaid#3052 by @MindaugasLaganeckas.

Important: I'm not sure whether to classify this as a feature or a fix.
Because this changes behaviour, maybe it is worth hiding this behind an option?
Or maybe we could add an option to use the old behaviour, something like --ignore-errors?

We should also add a warning to the release notes, e.g. something like

**⚠️ mermaid-cli now throws an error if mermaid fails, instead of making a diagram containing "Syntax Error"**

To simplify the src-test code, I used require("fs/promises");, which is only supported in NodeJS 14+. I don't think this is a big deal, since it's only in the test code, but I can change it to require("fs").promises (NodeJS 10+).

📋 Tasks

Make sure you

• 📖 have read the contribution guidelines
  • I tried to follow the old code style, e.g. I used "string" instead of 'string' when the old code used ". The style errors can be fixed with npx standard --fix though.
• 💻 have added unit/e2e tests (if appropriate)
  • The test code now runs on the test-negative folder too.
• 🔖 targeted master branch

[aloisklink]

I'm using require("fs/promises") here because it is what is recommended by the Node.JS documentation: see https://nodejs.org/docs/latest-v18.x/api/fs.html#promises-api

However, if we want to support Node.JS v10 and v12 (possibly not needed, since this is just test code), we can change to:

Suggested change

	const fs = require("fs/promises");
	const fs = require("fs").promises;

[MindaugasLaganeckas]

Thank you for helping me out!!! 🏅 😄 This has been a long awaited feature!

[aloisklink]

Thank you for helping me out!!! 🏅 😄 This has been a long awaited feature!

No worries 😄, I've got a library that uses mermaid-cli, so I was happy to help!