🐛 Avoid recursion in generators due to no tail-call optimizations #739
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Robdel12
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Update dependency @percy/cli to v1.0.0-beta.74 [](https://renovatebot.com) This PR contains the following updates: | Package | Change | Age | Adoption | Passing | Confidence | |---|---|---|---|---|---| | [`@percy/cli](https://togithub.com/percy/cli)` | [`1.0.0-beta.73` -> `1.0.0-beta.74`](https://renovatebot.com/diffs/npm/`@percy%2fcli/1.0.0-beta.73/1.0.0-beta.74)` | [](https://docs.renovatebot.com/merge-confidence/)` | [](https://docs.renovatebot.com/merge-confidence/)` | [](https://docs.renovatebot.com/merge-confidence/)` | [](https://docs.renovatebot.com/merge-confidence/)` | --- ### Release Notes <details> <summary>percy/cli</summary> ### [`v1.0.0-beta.74`](https://togithub.com/percy/cli/releases/v1.0.0-beta.74) [Compare Source](https://togithub.com/percy/cli/compare/v1.0.0-beta.73...v1.0.0-beta.74) <!-- Release notes generated using configuration in .github/release.yml at master --> #### What's Changed ##### 🐛 Bug Fixes - 🐛 Avoid recursion in generators due to no tail-call optimizations by [`@​wwilsman](https://togithub.com/wwilsman)` in [percy/cli#739 ##### ⬆️⬇️ Dependency Updates - ⬆️ Bump shelljs from 0.8.4 to 0.8.5 by [`@​dependabot](https://togithub.com/dependabot)` in [percy/cli#722 - ⬆️ Bump [`@​babel/preset-env](https://togithub.com/babel/preset-env)` from 7.16.7 to 7.16.8 by [`@​dependabot](https://togithub.com/dependabot)` in [percy/cli#723 - ⬆️ Bump ws from 8.4.0 to 8.4.2 by [`@​dependabot](https://togithub.com/dependabot)` in [percy/cli#729 - ⬆️ Bump nock from 13.2.1 to 13.2.2 by [`@​dependabot](https://togithub.com/dependabot)` in [percy/cli#725 - ⬆️ Bump log4js from 6.3.0 to 6.4.0 by [`@​dependabot](https://togithub.com/dependabot)` in [percy/cli#736 **Full Changelog**: percy/cli@v1.0.0-beta.73...v1.0.0-beta.74 </details> --- ### Configuration 📅 **Schedule**: "before 3am on Monday" (UTC). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, click this checkbox. --- This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#github/rust-lang/crates.io).
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What is this?
The check within the
waitForutil was originally created as a recursive function. With recent changes, the util was converted to make use of the cancelability of generators. However, generators cannot be tail-call optimized like the previous implementation was. This is due to technical reasons within V8 around the nature of how generator'snext()function handles script evaluation.Because the
waitForutil polls and may run for a long time, the lack of tail-call optimization caused the call stack to continuously grow the longer the util took to resolve. Eventually this could/will result in call stack errors (#735).This PR refactors the generator within the util to use a
while (true)loop rather than a recursiveyield*. The infinite loop is broken if thepredicatepasses at least once and at least one more time ifidleis provided.