fix: move from objects to Maps

[Yash-Singh1]

📑 Summary

Switches from objects to Maps in places where the keys accepted are user inputs.

Resolves #5451

📏 Design Decisions

Describe the way your implementation works or what design decisions you made if applicable.

This is a breaking change for v11 since it changes the structure of the databases and as such can break code that relies on the db, e.g.

https://github.com/excalidraw/mermaid-to-excalidraw/blob/d0b00dc63eeabd5e92ca3997650f47bf4901cb2c/src/parser/flowchart.ts#L226

Why?

The main reason for this change was so that we wouldn't have to validate for constructor and __proto__ (#5451) everytime we have to modify or get a property on the database objects. Another good reason would be that objects in JavaScript are generally designed to work like dynamic structs, where the JIT compiler would store the shape of the object and rereference that shape everytime that object is passed around. However, when we have a "map" with user-generated keys, Maps work better because they are designed for that purpose.

📋 Tasks

Make sure you

• 📖 have read the contribution guidelines
• 💻 have added necessary unit/e2e tests.
• 📓 have added documentation. Make sure MERMAID_RELEASE_VERSION is used for all new features.
• 🔖 targeted develop branch

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[codecov]

Codecov Report

Attention: Patch coverage is 0.50251% with 396 lines in your changes are missing coverage. Please review.

Project coverage is 5.73%. Comparing base (0326d89) to head (00eaebe).

Additional details and impacted files

@@            Coverage Diff             @@
##           develop   #5468      +/-   ##
==========================================
- Coverage     5.74%   5.73%   -0.01%     
==========================================
  Files          277     278       +1     
  Lines        41967   41991      +24     
  Branches       515     490      -25     
==========================================
  Hits          2409    2409              
- Misses       39558   39582      +24     

Flag	Coverage Δ
unit	5.73% <0.50%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
packages/mermaid/src/diagrams/gantt/ganttDb.js	77.47% <66.66%> (ø)
packages/mermaid/src/diagrams/sequence/svgDraw.js	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/class/classTypes.ts	0.00% <0.00%> (ø)
...ckages/mermaid/src/diagrams/gantt/ganttRenderer.js	0.00% <0.00%> (ø)
...ages/mermaid-flowchart-elk/src/flowRenderer-elk.js	0.00% <0.00%> (ø)
...ckages/mermaid/src/diagrams/class/classRenderer.js	0.00% <0.00%> (ø)
...ges/mermaid/src/diagrams/flowchart/flowRenderer.js	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/pie/pieRenderer.ts	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/er/erRenderer.js	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/pie/pieDb.ts	0.00% <0.00%> (ø)
... and 17 more

... and 1 file with indirect coverage changes

[sidharthv96]

Appreciate the effort! Can you take a look at the E2E failures?

[sidharthv96]

@Yash-Singh1 were you able to fix the tests?
Keeping this PR open for long will create more conflicts for you.

[Yash-Singh1]

Hi @sidharthv96, sorry for the late reply, I was busy with exams. I just fixed the e2e tests.

[sidharthv96]

No worries @Yash-Singh1! Hope they went well :)
Let's wait for a review from someone else as well, as the size is big.

[Yokozuna59]

Thanks for the great work!

I have a few comments. Is there a reason for some tests to be different? Like, some of them use it.each and some don't?

And I just would like the PR description to have the "why". Like listing the possible limitations of objects or downsides.

[aloisklink]

Awesome work @Yash-Singh1!!!

This is something I've wanted to do for a while too, so it's awesome to see you've done it (I can imagine that all the .js files must have been really painful without TypeScript).

I've got some minor nitpicks about not using the ! non-null assertion in TypeScript, but I've made a separate PR: #5518 for fixing this. You're welcome to merge it into your branch, or maybe we can merge this PR first, and then the other refactoring PR can also land.

[sidharthv96]

Merging this now, as both the review comments are non blockers, and can be done in a follow up PR.

[mermaid-bot]

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