fix(editor): Prevent infinite loop in expressions crashing the browser

[elsmr]

Summary

• Move logic to resolve expressions for parameters into 1 place and debounce updates
• Update using watchers (or computedWithControl) instead of computed to limit rerenders

To reproduce:

• Return an array from a node
• Add an expression in the next node that mutates the data {{ array.reverse() }}
• Before: browser crash, After: works fine

⚠️ The mutation of input data is not fixed in this PR

Related Linear tickets, Github issues, and Community forum posts

https://linear.app/n8n/issue/PAY-1261/bug-expression-freezing-workflow

Review / Merge checklist

• PR title and summary are descriptive. (conventions)
• Docs updated or follow-up ticket created.
• Tests included.
• PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)

[codecov]

Codecov Report

Attention: Patch coverage is 86.33094% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...editor-ui/src/composables/useResolvedExpression.ts	88.31%	9 Missing ⚠️
...es/editor-ui/src/components/ParameterInputList.vue	71.42%	7 Missing and 1 partial ⚠️
...src/components/AssignmentCollection/Assignment.vue	94.11%	1 Missing ⚠️
...editor-ui/src/components/ParameterInputWrapper.vue	94.11%	0 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!

[cypress]

n8n    Run #9075

Run Properties:   Passed #9075  •  51046014ed: 🌳 🖥️ browsers:node18.12.0-chrome107 🤖 elsmr 🗃️ e2e/*

Project	n8n
Branch Review	node-1517-expression-extensions-typing-reverse-crashes-fe-2
Run status	Passed #9075
Run duration	04m 26s
Commit	51046014ed: 🌳 🖥️ browsers:node18.12.0-chrome107 🤖 elsmr 🗃️ e2e/*
Committer	Elias Meire
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	2
Pending	5
Skipped	0
Passing	433
View all changes introduced in this branch ↗︎

[r00gm]

It works as promised ❤️

[github-actions]

✅ All Cypress E2E specs passed

[janober]

Got released with n8n@1.78.0