Jake Bailey

Revamp user preferences serialization/deserialization

1

In working on improving the fourslash testing, I wanted to make user preferences serializable, such that we can directly go from JSON to prefs and back, and therefore also test...

Often when I see people's profiles, the top allocator is `WriteByte`, all from the checker building runtime map keys. We stringify data to use as map keys for union types,...

This reapplies #2197 after it was reverted in #2250. This includes a few changes over #2197. - Actually check concurrently. Oops. - Caveat; each file gets its own goroutine. I...

"Options diagnostics" were just config file diagnostics + global diagnostics. This was odd, because we then took that in places and combined it with... config file diags and global diags....

I was working on another missing thing and there were some tests missing. So, add: - `numberOfErrorsInCurrentFile` - `noErrors` - `errorExistsAtRange` - `currentLineContentIs` - `currentFileContentIs` - `errorExistsBetweenMarkers` - `errorExistsAfterMarker` -...

DOM update 2025-12-10

13

Pulling in the latest since a bunch changed.

Always set up host in node builder

6

This is https://github.com/microsoft/typescript-go/pull/1604 but here.

Remove reportErrors check in relateVariances

74

Fixes #55217 Fixes #61524 As noted by @Andarist, this check is what causes things to differ between errors and non-error modes in relation, causing oddities when the same relation is...

"Never nullish" checks miss "never nullish" through parens

1

### 🔎 Search Terms never nullish parenthesis ### 🕗 Version & Regression Information - This changed between versions 5.8 and 5.9 ### ⏯ Playground Link https://www.typescriptlang.org/play/?#code/MYewdgzgLgBAHgLhgbxgTydATgSzAcxgB8YBXMAEwFMAzPKimAX2LMtvsYF43q6wGMAIYRhYNAG4AsAChZs0JFg0QIGDzgB+AHRoYmzTAAGqgA4Qj+wwCJr0mYugwARkKzqYACi26rxsxYAlH629grgECAANlTaUSD4nioggfaO0bHxia5YqUA ### 💻 Code ```ts...

Use `go test -json` in updateFailing, detect baseline errors

2

This does two things: - Uses `go test -json` to stream the output in a parseable format. - With the parsed output, read each failing test's output to see if...