Unit tests should be fast 🐎

This is a continuation of https://github.com/microsoft/vscode/issues/134972. A unit test shouldn’t take longer than 50ms. An easy way to “speed up” setTimeout and friends is @hediet’s runWithFakedTimers-utility

To reproduce these numbers

• run ./scripts/test.sh --reporter json > ~/Desktop/test_out.json
• open the file and remove the first non-json lines
• run jq '.tests | map(select(.duration > 50)) | sort_by(.duration) | [.[] | "- [ ] " + (.duration|tostring) + "ms, " + .fullTitle ]' ~/Desktop/test_out.json

tests slower than 50ms

• 51ms, ExtHostAuthentication createIfNone - false
• 52ms, IndexDBStorageDatabase (browser) Clear
• 54ms, MarkdownRenderer Code block renderer asyncRenderCallback should not be invoked if result is immediately disposed
• 54ms, Notebook Find Update find matches basics
• 56ms, Async Limiter async
• 57ms, PFS writeFile (string) - flush on write
• 57ms, ExtHostAuthentication Can get multiple sessions (with different scopes) in one extension
• 57ms, ExtHostAuthentication Can get multiple sessions (from different providers) in one extension
• 57ms, Notebook Find Update find matches basics 3
• 57ms, Notebook Find Reset when match not found, #127198
• 58ms, Notebook Find Update find matches, #112748
• 60ms, FoldingRanges test max folding regions
• 60ms, ExtHostAuthentication clearSessionPreference - true
• 61ms, Notebook Find Update find matches basics 2
• 69ms, SQLite Storage Library very large item value
• 74ms, ExtHostAuthentication silently getting session should return a session (if any) regardless of preference - fixes #137819
• 76ms, Workbench - TerminalWordLinkDetector should link words as defined by wordSeparators
• 76ms, Files - TextFileEditorModel backup and restore (large, #121347)
• 97ms, TerminalProfileService should get profiles from remoteTerminalService when there is a remote authority
• 107ms, MarkdownRenderer Code block renderer asyncRenderCallback should not be invoked if dispose is called before code block is rendered
• 121ms, IndexDBStorageDatabase (browser) Basics
• 140ms, Native Modules (Windows, macOS) keytar
• 157ms, Editor Controller issue #23913: Greater than 1000+ multi cursor typing replacement text appears inverted, lines begin to drop off selection
• 201ms, Encoding autoGuessEncoding (UTF8)

[bpasero]

Working on a couple of things with https://github.com/microsoft/vscode/pull/155147

• more adoption of runWithFakedTimers 🚀
• figured out that we run a fs.fdatasyncSync(fd); for every writeFile to ensure data is flushed to disk which makes writing slower and figured out a way to disable this for most tests except the ones that want to test writing specifically
• adopted inMemory scheme for some of my tests and even found a bug in our in-memory fs-provider

Before: scripts/test.sh 23.83s user 5.24s system 41% cpu 1:10.09 total

After: scripts/test.sh 24.31s user 5.06s system 47% cpu 1:02.10 total

[jrieken]

@bpasero One thing we noticed is that quite some tests use the DiskFileSystemProvider. Those will surely benefit from an InMem-provider