Client does not start

[tensionhead]

Describe the bug
After global (or local) installation with npm, hitting mmdc in the terminal gives:

file:///usr/local/lib/node_modules/@mermaid-js/mermaid-cli/src/index.js:260
      const svg = container.getElementsByTagName?.('svg')?.[0]
                                                 ^

SyntaxError: Unexpected token '.'
    at Loader.moduleStrategy (internal/modules/esm/translators.js:133:18)

To Reproduce
Steps to reproduce the behavior:

1. Install the mermaid client via npm install -g @mermaid-js/mermaid-cli
2. run the mmdc client in a terminal

Desktop :

OS: Ubuntu 22.04

Additional context
I also tried the alternative installation instructions, a local installation via npm yields the exact same error. Installation via yarn failed because of dependecy issues.

[KSR-Yasuda]

Perhaps are you using Node.js < 14.x ?
Optional chaining (?.) syntax is supported from Node v14.

[tensionhead]

Indeed, the standard Node.js installation from the Ubuntu software sources gives version v12.x. Thanks, I am gonna check how to install a >= v14.x version!

EDIT: Ok following this guide, I got Node.js 14.4 and npm 6.14.5 installed.

However, after re-installing the mermaid-cli I now get when starting the mmdc client in the terminal:

internal/modules/run_main.js:54
    internalBinding('errors').triggerUncaughtException(
                              ^

Error [ERR_MODULE_NOT_FOUND]: Cannot find package '/usr/local/lib/node_modules/@mermaid-js/mermaid-cli/node_modules/chalk/source/node_modules/' imported from /usr/local/lib/node_modules/@mermaid-js/mermaid-cli/node_modules/chalk/source/index.js
    at packageMainResolve (internal/modules/esm/resolve.js:465:9)
    at packageResolve (internal/modules/esm/resolve.js:607:14)
    at moduleResolve (internal/modules/esm/resolve.js:659:14)
    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:752:11)
    at Loader.resolve (internal/modules/esm/loader.js:97:40)
    at Loader.getModuleJob (internal/modules/esm/loader.js:242:28)
    at ModuleWrap.<anonymous> (internal/modules/esm/module_job.js:50:40)
    at link (internal/modules/esm/module_job.js:49:36) {
  code: 'ERR_MODULE_NOT_FOUND'

[tensionhead]

Ok I think I got it, using

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash

then nvm install --lts and finally npm install @mermaid-js/mermaid-cli I got the client running! Node.js is now v18.17.0 and mmdc works 🚀

[aloisklink]

Yep, sorry, we only support Node v14.13 and up, and we'll soon have to drop Node v14 support, since it's no longer supported by the Node.JS team, and many of our dependencies are dropping support too.

It's listed in

mermaid-cli/package.json

Line 13 in 57f8262

"node": "^14.13 || >=16.0"

, so NPM should have printed a warning about it, but your NPM version might have been too old for this!

Node.js installation from the Ubuntu software sources

FYI, I would highly recommend not using the default Ubuntu apt repo for Node.JS. LTS Node.JS releases are only actively maintained by the Node.JS team for 2.5 years (see https://github.com/nodejs/release#release-schedule). Afterwards, you're relying on the Debian/Ubuntu team to fix security issues, but they generally struggle with backporting security fixes, since Node.JS is a very large project.

NVM is great if you're a developer, but since it's doesn't automatically update Node.JS, it's not great from a security standpoint.

If you're running Ubuntu, snap or the NodeSource apt repo are generally what I'd recommend using to install Node.JS, so that you'll get automatic updates!