Bound createAnonymousTypeNodeEx reuse for recursive instantiation expression types

[Copilot]

A recursive typeof X<...> whose entity name isn't accessible from the current scope sends the node builder into unbounded recursion: when tryReuseExistingNonParameterTypeNode fails for an InstantiationExpressionType, the recovery boundary's fallback re-enters typeToTypeNode on the same type, which retries reuse on the same node, stacking another recovery boundary each time until the goroutine stack overflows.

Changes

• createAnonymousTypeNodeEx (internal/checker/nodebuilderimpl.go): wrap the tryReuseExistingNonParameterTypeNode call for InstantiationExpressionType with a visitedTypes add/delete so the inner re-entry hits the existing visitedTypes.Has guard and returns an elided-information placeholder instead of recursing.
• Regression test: testdata/tests/cases/compiler/symbolToNodeBoundaryNoStackOverflow.ts (the repro from the upstream issue).

if ast.IsTypeQueryNode(existing) && b.getTypeFromTypeNode(existing, false) == t {
    if b.ctx.visitedTypes.Has(typeId) {
        return b.createElidedInformationPlaceholder()
    }
    b.ctx.visitedTypes.Add(typeId)
    typeNode := b.tryReuseExistingNonParameterTypeNode(existing, t, nil, nil)
    b.ctx.visitedTypes.Delete(typeId)
    if typeNode != nil {
        return typeNode
    }
}

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Fixes an unbounded recursion/stack overflow in node building for recursive typeof X<...> instantiation expression types by bounding reuse attempts with the existing visitedTypes recursion guard, and adds a regression test to prevent reintroduction.

Changes:

• Add a visitedTypes add/delete guard around tryReuseExistingNonParameterTypeNode when reusing an existing typeof node for an InstantiationExpressionType.
• Add a compiler regression test reproducing the recursive typeof node.getNextNode<any> scenario.
• Add/update baselines (types, symbols, errors) for the new test.

Show a summary per file

File	Description
internal/checker/nodebuilderimpl.go	Bounds recursion during typeof reuse attempts by marking the instantiation type as visited.
testdata/tests/cases/compiler/symbolToNodeBoundaryNoStackOverflow.ts	Adds a repro case that previously triggered unbounded recursion/stack overflow.
testdata/baselines/reference/compiler/symbolToNodeBoundaryNoStackOverflow.types	Baseline output for types to validate the compiler output for the new test case.
testdata/baselines/reference/compiler/symbolToNodeBoundaryNoStackOverflow.symbols	Baseline output for symbols to validate symbol emission for the new test case.
testdata/baselines/reference/compiler/symbolToNodeBoundaryNoStackOverflow.errors.txt	Baseline output for the expected error(s) in the new test case.

Copilot's findings

• Files reviewed: 5/5 changed files
• Comments generated: 2

[Copilot]

Consider using a defer b.ctx.visitedTypes.Delete(typeId) immediately after Add so the visited set is reliably unwound even if this code is refactored later (e.g., additional early returns added) or if tryReuseExistingNonParameterTypeNode ever panics. This keeps the recursion-tracking state consistent and reduces the chance of hard-to-debug downstream behavior.

Suggested change

	typeNode := b.tryReuseExistingNonParameterTypeNode(existing, t, nil, nil)
	b.ctx.visitedTypes.Delete(typeId)
	defer b.ctx.visitedTypes.Delete(typeId)
	typeNode := b.tryReuseExistingNonParameterTypeNode(existing, t, nil, nil)

[Copilot]

The comment says the recursion bottoms out via the "visitedTypes guard below", but the guard is now immediately in this block. Suggest tweaking wording to avoid directional references (e.g., just "via the visitedTypes guard") to keep the comment accurate if surrounding code moves.

Suggested change

	// attempt so the inner recursion bottoms out via the visitedTypes guard below.
	// attempt so the inner recursion bottoms out via the visitedTypes guard.