ensure getComputedStyle always has a valid canvas provided

[DAcodedBEAT]

Expected behavior

getComputedStyle() from helpers.dom.js should be called with valid canvas values provided.

Current behavior

TypeError: Cannot read properties of null (reading 'ownerDocument')
  at getComputedStyle(../../node_modules/chart.js/dist/chunks/helpers.segment.js:1841:47)
  at getMaximumSize(../../node_modules/chart.js/dist/chunks/helpers.segment.js:1933:17)
  at DomPlatform.getMaximumSize(../../node_modules/chart.js/dist/chart.js:3435:12)
  at _a._resize(../../node_modules/chart.js/dist/chart.js:5700:35)
  at detached(../../node_modules/chart.js/dist/chart.js:6267:12)
  at _a.bindResponsiveEvents(../../node_modules/chart.js/dist/chart.js:6273:16)
  at _a.bindEvents(../../node_modules/chart.js/dist/chart.js:6215:12)
  at _a._checkEventBindings(../../node_modules/chart.js/dist/chart.js:5911:12)
  at _a.update(../../node_modules/chart.js/dist/chart.js:5860:10)
  at this._doResize(../../node_modules/chart.js/dist/chart.js:5628:46)
  at sentryWrapped(../../node_modules/@sentry/browser/esm/helpers.js:36:17)

From sentry:

Reproducible sample

.

Optional extra steps/info to reproduce

No response

chart.js version

4.4.3

Browser name and version

Experienced on Chrome >=124.0.0 according to my project's Sentry, but probably impacts others since this is an issue with the provided parameter.

Link to your project

No response

[DAcodedBEAT]

@etimberg / @LeeLenaleee I used optional chaining and null coalescing because of this discussion - #11651 (comment), which is why the CI pipeline failed. Give the word and I'll remove the rule so this pipeline can pass.

[LeeLenaleee]

I guess that this was not meant to be?

[DAcodedBEAT]

this was removed since it didn't provide any additional information than the function signature already provided (not even variable types). If you still want this, I can revert this change.

[DAcodedBEAT]

@etimberg / @LeeLenaleee can you re-review this?