[PR#5468] refactor: remove TypeScript non null assertions

[aloisklink]

📑 Summary

Note

This PR does not target the develop branch. Instead it targets:

• fix: move from objects to Maps #5468

I'm not a big fan of using TypeScript's non-null assertion operator (e.g. map.get(val)!).

Instead, I've tried to rewrite the code when possible, so it's not needed. E.g., instead of doing:

if (map.has(x)) {
  return map.get(x);
}

I've tried to do things that TypeScript can understand, e.g.

const val = map.get(x);
if (val !== undefined) {
  return val;
}

There's also some other misc improvements I found when reviewing #5468.

There should be no functional changes to the code, this is a refactoring only change.

📏 Design Decisions

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

📋 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
  • NOPE, targets fix: move from objects to Maps #5468

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 84 lines in your changes are missing coverage. Please review.

Project coverage is 5.72%. Comparing base (50c9ede) to head (730fa89).

Additional details and impacted files

@@           Coverage Diff            @@
##           fix/maps   #5518   +/-   ##
========================================
  Coverage      5.72%   5.72%           
========================================
  Files           278     277    -1     
  Lines         42018   42012    -6     
  Branches        490     515   +25     
========================================
  Hits           2407    2407           
+ Misses        39611   39605    -6     

Flag	Coverage Δ
unit	5.72% <0.00%> (+<0.01%)	⬆️

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

Files	Coverage Δ
packages/mermaid/src/diagrams/git/gitGraphAst.js	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/state/stateDb.js	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/pie/pieRenderer.ts	0.00% <0.00%> (ø)
packages/mermaid/src/mermaidAPI.ts	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/class/classDb.ts	0.00% <0.00%> (ø)
...ges/mermaid/src/diagrams/class/classRenderer-v2.ts	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/sankey/sankeyDB.ts	0.00% <0.00%> (ø)
...ckages/mermaid/src/diagrams/sequence/sequenceDb.ts	0.00% <0.00%> (ø)
...id/src/diagrams/requirement/requirementRenderer.js	0.00% <0.00%> (ø)
packages/mermaid/src/diagrams/block/blockDB.ts	0.00% <0.00%> (ø)
... and 1 more

... and 1 file with indirect coverage changes

[Yash-Singh1]

Yeah, this is definitely a better way to interact with Maps 👍🏾 .