From 424e7673b56c9aa0f86a6020daa18e817d837f39 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 12:27:45 -0700
Subject: [PATCH 1/9] Clear node builder links when done

---
 internal/checker/nodebuilder.go | 6 ++----
 internal/core/linkstore.go      | 7 +++++++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 0a8570ea8f..74a835ee73 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -43,6 +43,8 @@ func (b *NodeBuilder) popContext() {
 	stackSize := len(b.ctxStack)
 	if stackSize == 0 {
 		b.impl.ctx = nil
+		b.impl.links.Clear()
+		b.impl.symbolLinks.Clear()
 	} else {
 		b.impl.ctx = b.ctxStack[stackSize-1]
 		b.ctxStack = b.ctxStack[:stackSize-1]
@@ -169,7 +171,3 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 	impl := newNodeBuilderImpl(ch, e)
 	return &NodeBuilder{impl: impl, ctxStack: make([]*NodeBuilderContext, 0, 1), host: ch.program}
 }
-
-func (c *Checker) GetDiagnosticNodeBuilder() *NodeBuilder {
-	return c.nodeBuilder
-}
diff --git a/internal/core/linkstore.go b/internal/core/linkstore.go
index c1b05ee7e8..25cd3d4553 100644
--- a/internal/core/linkstore.go
+++ b/internal/core/linkstore.go
@@ -28,3 +28,10 @@ func (s *LinkStore[K, V]) Has(key K) bool {
 func (s *LinkStore[K, V]) TryGet(key K) *V {
 	return s.entries[key]
 }
+
+func (s *LinkStore[K, V]) Clear() {
+	clear(s.entries)
+	*s = LinkStore[K, V]{
+		entries: s.entries,
+	}
+}

From e1397f514604275cd713563ebfc3e4be79bc6c80 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 12:58:45 -0700
Subject: [PATCH 2/9] what if fresh builder each time

---
 internal/checker/checker.go     |  5 -----
 internal/checker/nodebuilder.go |  4 ++++
 internal/checker/printer.go     | 26 +++++++++++++++-----------
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/internal/checker/checker.go b/internal/checker/checker.go
index 75b2f72d53..244a106eed 100644
--- a/internal/checker/checker.go
+++ b/internal/checker/checker.go
@@ -22,7 +22,6 @@ import (
 	"github.com/microsoft/typescript-go/internal/jsnum"
 	"github.com/microsoft/typescript-go/internal/module"
 	"github.com/microsoft/typescript-go/internal/modulespecifiers"
-	"github.com/microsoft/typescript-go/internal/printer"
 	"github.com/microsoft/typescript-go/internal/scanner"
 	"github.com/microsoft/typescript-go/internal/stringutil"
 	"github.com/microsoft/typescript-go/internal/tsoptions"
@@ -847,8 +846,6 @@ type Checker struct {
 	markNodeAssignments                         func(*ast.Node) bool
 	emitResolver                                *emitResolver
 	emitResolverOnce                            sync.Once
-	diagnosticConstructionContext               *printer.EmitContext
-	nodeBuilder                                 *NodeBuilder
 	_jsxNamespace                               string
 	_jsxFactoryEntity                           *ast.Node
 	skipDirectInferenceNodes                    collections.Set[*ast.Node]
@@ -1065,8 +1062,6 @@ func NewChecker(program Program) *Checker {
 	c.getGlobalClassAccessorDecoratorTargetType = c.getGlobalTypeResolver("ClassAccessorDecoratorTarget", 2 /*arity*/, true /*reportErrors*/)
 	c.getGlobalClassAccessorDecoratorResultType = c.getGlobalTypeResolver("ClassAccessorDecoratorResult", 2 /*arity*/, true /*reportErrors*/)
 	c.getGlobalClassFieldDecoratorContextType = c.getGlobalTypeResolver("ClassFieldDecoratorContext", 2 /*arity*/, true /*reportErrors*/)
-	c.diagnosticConstructionContext = printer.NewEmitContext()
-	c.nodeBuilder = NewNodeBuilder(c, c.diagnosticConstructionContext)
 	c.initializeClosures()
 	c.initializeIterationResolvers()
 	c.initializeChecker()
diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 74a835ee73..ef316698f9 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -171,3 +171,7 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 	impl := newNodeBuilderImpl(ch, e)
 	return &NodeBuilder{impl: impl, ctxStack: make([]*NodeBuilderContext, 0, 1), host: ch.program}
 }
+
+func (c *Checker) NewNodeBuilder() *NodeBuilder {
+	return NewNodeBuilder(c, printer.NewEmitContext())
+}
diff --git a/internal/checker/printer.go b/internal/checker/printer.go
index 4b668e2c16..58b5c86d72 100644
--- a/internal/checker/printer.go
+++ b/internal/checker/printer.go
@@ -182,7 +182,8 @@ func (c *Checker) typeToStringEx(t *Type, enclosingDeclaration *ast.Node, flags
 	if noTruncation {
 		combinedFlags = combinedFlags | nodebuilder.FlagsNoTruncation
 	}
-	typeNode := c.nodeBuilder.TypeToTypeNode(t, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
+	nodeBuilder := c.NewNodeBuilder()
+	typeNode := nodeBuilder.TypeToTypeNode(t, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
 	if typeNode == nil {
 		panic("should always get typenode")
 	}
@@ -190,9 +191,9 @@ func (c *Checker) typeToStringEx(t *Type, enclosingDeclaration *ast.Node, flags
 	// Otherwise, we always strip comments out.
 	var printer *printer.Printer
 	if t == c.unresolvedType {
-		printer = createPrinterWithDefaults(c.diagnosticConstructionContext)
+		printer = createPrinterWithDefaults(nodeBuilder.EmitContext())
 	} else {
-		printer = createPrinterWithRemoveComments(c.diagnosticConstructionContext)
+		printer = createPrinterWithRemoveComments(nodeBuilder.EmitContext())
 	}
 	var sourceFile *ast.SourceFile
 	if enclosingDeclaration != nil {
@@ -245,22 +246,23 @@ func (c *Checker) symbolToStringEx(symbol *ast.Symbol, enclosingDeclaration *ast
 		internalNodeFlags |= nodebuilder.InternalFlagsWriteComputedProps
 	}
 
+	nodeBuilder := c.NewNodeBuilder()
 	var sourceFile *ast.SourceFile
 	if enclosingDeclaration != nil {
 		sourceFile = ast.GetSourceFileOfNode(enclosingDeclaration)
 	}
 	var printer_ *printer.Printer
 	if enclosingDeclaration != nil && enclosingDeclaration.Kind == ast.KindSourceFile {
-		printer_ = createPrinterWithRemoveCommentsNeverAsciiEscape(c.diagnosticConstructionContext)
+		printer_ = createPrinterWithRemoveCommentsNeverAsciiEscape(nodeBuilder.EmitContext())
 	} else {
-		printer_ = createPrinterWithRemoveComments(c.diagnosticConstructionContext)
+		printer_ = createPrinterWithRemoveComments(nodeBuilder.EmitContext())
 	}
 
 	var builder func(symbol *ast.Symbol, meaning ast.SymbolFlags, enclosingDeclaration *ast.Node, flags nodebuilder.Flags, internalFlags nodebuilder.InternalFlags, tracker nodebuilder.SymbolTracker) *ast.Node
 	if flags&SymbolFormatFlagsAllowAnyNodeKind != 0 {
-		builder = c.nodeBuilder.SymbolToNode
+		builder = nodeBuilder.SymbolToNode
 	} else {
-		builder = c.nodeBuilder.SymbolToEntityName
+		builder = nodeBuilder.SymbolToEntityName
 	}
 	entity := builder(symbol, meaning, enclosingDeclaration, nodeFlags, internalNodeFlags, nil)         // TODO: GH#18217
 	printer_.Write(entity /*sourceFile*/, sourceFile, getTrailingSemicolonDeferringWriter(writer), nil) // TODO: GH#18217
@@ -294,9 +296,10 @@ func (c *Checker) signatureToStringEx(signature *Signature, enclosingDeclaration
 	writer, putWriter := printer.GetSingleLineStringWriter()
 	defer putWriter()
 
+	nodeBuilder := c.NewNodeBuilder()
 	combinedFlags := toNodeBuilderFlags(flags) | nodebuilder.FlagsIgnoreErrors | nodebuilder.FlagsWriteTypeParametersInQualifiedName
-	sig := c.nodeBuilder.SignatureToSignatureDeclaration(signature, sigOutput, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
-	printer_ := createPrinterWithRemoveCommentsOmitTrailingSemicolon(c.diagnosticConstructionContext)
+	sig := nodeBuilder.SignatureToSignatureDeclaration(signature, sigOutput, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
+	printer_ := createPrinterWithRemoveCommentsOmitTrailingSemicolon(nodeBuilder.EmitContext())
 	var sourceFile *ast.SourceFile
 	if enclosingDeclaration != nil {
 		sourceFile = ast.GetSourceFileOfNode(enclosingDeclaration)
@@ -312,9 +315,10 @@ func (c *Checker) typePredicateToString(typePredicate *TypePredicate) string {
 func (c *Checker) typePredicateToStringEx(typePredicate *TypePredicate, enclosingDeclaration *ast.Node, flags TypeFormatFlags) string {
 	writer, putWriter := printer.GetSingleLineStringWriter()
 	defer putWriter()
+	nodeBuilder := c.NewNodeBuilder()
 	combinedFlags := toNodeBuilderFlags(flags) | nodebuilder.FlagsIgnoreErrors | nodebuilder.FlagsWriteTypeParametersInQualifiedName
-	predicate := c.nodeBuilder.TypePredicateToTypePredicateNode(typePredicate, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil) // TODO: GH#18217
-	printer_ := createPrinterWithRemoveComments(c.diagnosticConstructionContext)
+	predicate := nodeBuilder.TypePredicateToTypePredicateNode(typePredicate, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil) // TODO: GH#18217
+	printer_ := createPrinterWithRemoveComments(nodeBuilder.EmitContext())
 	var sourceFile *ast.SourceFile
 	if enclosingDeclaration != nil {
 		sourceFile = ast.GetSourceFileOfNode(enclosingDeclaration)

From 3b5d48f82713f822328f0e42bd1531da78667fe2 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 13:35:33 -0700
Subject: [PATCH 3/9] Revert "Clear node builder links when done"

This reverts commit 424e7673b56c9aa0f86a6020daa18e817d837f39.
---
 internal/checker/nodebuilder.go | 6 ++++--
 internal/core/linkstore.go      | 7 -------
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index ef316698f9..78a27bd6f5 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -43,8 +43,6 @@ func (b *NodeBuilder) popContext() {
 	stackSize := len(b.ctxStack)
 	if stackSize == 0 {
 		b.impl.ctx = nil
-		b.impl.links.Clear()
-		b.impl.symbolLinks.Clear()
 	} else {
 		b.impl.ctx = b.ctxStack[stackSize-1]
 		b.ctxStack = b.ctxStack[:stackSize-1]
@@ -175,3 +173,7 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 func (c *Checker) NewNodeBuilder() *NodeBuilder {
 	return NewNodeBuilder(c, printer.NewEmitContext())
 }
+
+func (c *Checker) GetDiagnosticNodeBuilder() *NodeBuilder {
+	return c.nodeBuilder
+}
diff --git a/internal/core/linkstore.go b/internal/core/linkstore.go
index 25cd3d4553..c1b05ee7e8 100644
--- a/internal/core/linkstore.go
+++ b/internal/core/linkstore.go
@@ -28,10 +28,3 @@ func (s *LinkStore[K, V]) Has(key K) bool {
 func (s *LinkStore[K, V]) TryGet(key K) *V {
 	return s.entries[key]
 }
-
-func (s *LinkStore[K, V]) Clear() {
-	clear(s.entries)
-	*s = LinkStore[K, V]{
-		entries: s.entries,
-	}
-}

From a9be7e611148516116086562ad852a934cec925c Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 13:38:26 -0700
Subject: [PATCH 4/9] oops

---
 internal/checker/nodebuilder.go | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 78a27bd6f5..13c8a5e497 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -173,7 +173,3 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 func (c *Checker) NewNodeBuilder() *NodeBuilder {
 	return NewNodeBuilder(c, printer.NewEmitContext())
 }
-
-func (c *Checker) GetDiagnosticNodeBuilder() *NodeBuilder {
-	return c.nodeBuilder
-}

From 254241cafc3f356ffa6ba538f7abfeeb646df5ea Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 13:55:47 -0700
Subject: [PATCH 5/9] Share a NodeBuilder during checkSourceFile

---
 internal/checker/checker.go     | 4 ++++
 internal/checker/nodebuilder.go | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/internal/checker/checker.go b/internal/checker/checker.go
index 244a106eed..e617fda51c 100644
--- a/internal/checker/checker.go
+++ b/internal/checker/checker.go
@@ -22,6 +22,7 @@ import (
 	"github.com/microsoft/typescript-go/internal/jsnum"
 	"github.com/microsoft/typescript-go/internal/module"
 	"github.com/microsoft/typescript-go/internal/modulespecifiers"
+	"github.com/microsoft/typescript-go/internal/printer"
 	"github.com/microsoft/typescript-go/internal/scanner"
 	"github.com/microsoft/typescript-go/internal/stringutil"
 	"github.com/microsoft/typescript-go/internal/tsoptions"
@@ -846,6 +847,7 @@ type Checker struct {
 	markNodeAssignments                         func(*ast.Node) bool
 	emitResolver                                *emitResolver
 	emitResolverOnce                            sync.Once
+	nodeBuilderDuringCheckSourceFile            *NodeBuilder
 	_jsxNamespace                               string
 	_jsxFactoryEntity                           *ast.Node
 	skipDirectInferenceNodes                    collections.Set[*ast.Node]
@@ -2107,6 +2109,7 @@ func (c *Checker) checkSourceFile(ctx context.Context, sourceFile *ast.SourceFil
 	links := c.sourceFileLinks.Get(sourceFile)
 	if !links.typeChecked {
 		c.ctx = ctx
+		c.nodeBuilderDuringCheckSourceFile = NewNodeBuilder(c, printer.NewEmitContext())
 		// Grammar checking
 		c.checkGrammarSourceFile(sourceFile)
 		c.renamedBindingElementsInTypes = nil
@@ -2129,6 +2132,7 @@ func (c *Checker) checkSourceFile(ctx context.Context, sourceFile *ast.SourceFil
 			c.wasCanceled = true
 		}
 		c.ctx = nil
+		c.nodeBuilderDuringCheckSourceFile = nil
 		links.typeChecked = true
 	}
 }
diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 13c8a5e497..25d50d918f 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -171,5 +171,8 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 }
 
 func (c *Checker) NewNodeBuilder() *NodeBuilder {
+	if c.nodeBuilderDuringCheckSourceFile != nil {
+		return c.nodeBuilderDuringCheckSourceFile
+	}
 	return NewNodeBuilder(c, printer.NewEmitContext())
 }

From 6c8bcf871056cd6b2ec6bc4ab34454268e4cee5c Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 14:04:03 -0700
Subject: [PATCH 6/9] Avoid too much recreation

---
 internal/checker/checker.go     | 5 +++--
 internal/checker/nodebuilder.go | 5 ++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/internal/checker/checker.go b/internal/checker/checker.go
index e617fda51c..55a260992a 100644
--- a/internal/checker/checker.go
+++ b/internal/checker/checker.go
@@ -22,7 +22,6 @@ import (
 	"github.com/microsoft/typescript-go/internal/jsnum"
 	"github.com/microsoft/typescript-go/internal/module"
 	"github.com/microsoft/typescript-go/internal/modulespecifiers"
-	"github.com/microsoft/typescript-go/internal/printer"
 	"github.com/microsoft/typescript-go/internal/scanner"
 	"github.com/microsoft/typescript-go/internal/stringutil"
 	"github.com/microsoft/typescript-go/internal/tsoptions"
@@ -847,6 +846,7 @@ type Checker struct {
 	markNodeAssignments                         func(*ast.Node) bool
 	emitResolver                                *emitResolver
 	emitResolverOnce                            sync.Once
+	inCheckSourceFile                           bool
 	nodeBuilderDuringCheckSourceFile            *NodeBuilder
 	_jsxNamespace                               string
 	_jsxFactoryEntity                           *ast.Node
@@ -2109,7 +2109,7 @@ func (c *Checker) checkSourceFile(ctx context.Context, sourceFile *ast.SourceFil
 	links := c.sourceFileLinks.Get(sourceFile)
 	if !links.typeChecked {
 		c.ctx = ctx
-		c.nodeBuilderDuringCheckSourceFile = NewNodeBuilder(c, printer.NewEmitContext())
+		c.inCheckSourceFile = true
 		// Grammar checking
 		c.checkGrammarSourceFile(sourceFile)
 		c.renamedBindingElementsInTypes = nil
@@ -2132,6 +2132,7 @@ func (c *Checker) checkSourceFile(ctx context.Context, sourceFile *ast.SourceFil
 			c.wasCanceled = true
 		}
 		c.ctx = nil
+		c.inCheckSourceFile = false
 		c.nodeBuilderDuringCheckSourceFile = nil
 		links.typeChecked = true
 	}
diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 25d50d918f..87112c4db2 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -171,7 +171,10 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 }
 
 func (c *Checker) NewNodeBuilder() *NodeBuilder {
-	if c.nodeBuilderDuringCheckSourceFile != nil {
+	if c.inCheckSourceFile {
+		if c.nodeBuilderDuringCheckSourceFile == nil {
+			c.nodeBuilderDuringCheckSourceFile = NewNodeBuilder(c, printer.NewEmitContext())
+		}
 		return c.nodeBuilderDuringCheckSourceFile
 	}
 	return NewNodeBuilder(c, printer.NewEmitContext())

From 78c8a46db718ce3d832481a055e2e53ace6c2d2f Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 14:04:39 -0700
Subject: [PATCH 7/9] rename

---
 internal/checker/nodebuilder.go | 2 +-
 internal/checker/printer.go     | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 87112c4db2..8db58d4328 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -170,7 +170,7 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 	return &NodeBuilder{impl: impl, ctxStack: make([]*NodeBuilderContext, 0, 1), host: ch.program}
 }
 
-func (c *Checker) NewNodeBuilder() *NodeBuilder {
+func (c *Checker) GetNodeBuilder() *NodeBuilder {
 	if c.inCheckSourceFile {
 		if c.nodeBuilderDuringCheckSourceFile == nil {
 			c.nodeBuilderDuringCheckSourceFile = NewNodeBuilder(c, printer.NewEmitContext())
diff --git a/internal/checker/printer.go b/internal/checker/printer.go
index 58b5c86d72..3fb4cead0b 100644
--- a/internal/checker/printer.go
+++ b/internal/checker/printer.go
@@ -182,7 +182,7 @@ func (c *Checker) typeToStringEx(t *Type, enclosingDeclaration *ast.Node, flags
 	if noTruncation {
 		combinedFlags = combinedFlags | nodebuilder.FlagsNoTruncation
 	}
-	nodeBuilder := c.NewNodeBuilder()
+	nodeBuilder := c.GetNodeBuilder()
 	typeNode := nodeBuilder.TypeToTypeNode(t, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
 	if typeNode == nil {
 		panic("should always get typenode")
@@ -246,7 +246,7 @@ func (c *Checker) symbolToStringEx(symbol *ast.Symbol, enclosingDeclaration *ast
 		internalNodeFlags |= nodebuilder.InternalFlagsWriteComputedProps
 	}
 
-	nodeBuilder := c.NewNodeBuilder()
+	nodeBuilder := c.GetNodeBuilder()
 	var sourceFile *ast.SourceFile
 	if enclosingDeclaration != nil {
 		sourceFile = ast.GetSourceFileOfNode(enclosingDeclaration)
@@ -296,7 +296,7 @@ func (c *Checker) signatureToStringEx(signature *Signature, enclosingDeclaration
 	writer, putWriter := printer.GetSingleLineStringWriter()
 	defer putWriter()
 
-	nodeBuilder := c.NewNodeBuilder()
+	nodeBuilder := c.GetNodeBuilder()
 	combinedFlags := toNodeBuilderFlags(flags) | nodebuilder.FlagsIgnoreErrors | nodebuilder.FlagsWriteTypeParametersInQualifiedName
 	sig := nodeBuilder.SignatureToSignatureDeclaration(signature, sigOutput, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
 	printer_ := createPrinterWithRemoveCommentsOmitTrailingSemicolon(nodeBuilder.EmitContext())
@@ -315,7 +315,7 @@ func (c *Checker) typePredicateToString(typePredicate *TypePredicate) string {
 func (c *Checker) typePredicateToStringEx(typePredicate *TypePredicate, enclosingDeclaration *ast.Node, flags TypeFormatFlags) string {
 	writer, putWriter := printer.GetSingleLineStringWriter()
 	defer putWriter()
-	nodeBuilder := c.NewNodeBuilder()
+	nodeBuilder := c.GetNodeBuilder()
 	combinedFlags := toNodeBuilderFlags(flags) | nodebuilder.FlagsIgnoreErrors | nodebuilder.FlagsWriteTypeParametersInQualifiedName
 	predicate := nodeBuilder.TypePredicateToTypePredicateNode(typePredicate, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil) // TODO: GH#18217
 	printer_ := createPrinterWithRemoveComments(nodeBuilder.EmitContext())

From 04cec18dc79292e3970b189b8eb074892b530579 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Wed, 25 Jun 2025 14:04:59 -0700
Subject: [PATCH 8/9] internal

---
 internal/checker/nodebuilder.go | 2 +-
 internal/checker/printer.go     | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 8db58d4328..41c4b22235 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -170,7 +170,7 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 	return &NodeBuilder{impl: impl, ctxStack: make([]*NodeBuilderContext, 0, 1), host: ch.program}
 }
 
-func (c *Checker) GetNodeBuilder() *NodeBuilder {
+func (c *Checker) getNodeBuilder() *NodeBuilder {
 	if c.inCheckSourceFile {
 		if c.nodeBuilderDuringCheckSourceFile == nil {
 			c.nodeBuilderDuringCheckSourceFile = NewNodeBuilder(c, printer.NewEmitContext())
diff --git a/internal/checker/printer.go b/internal/checker/printer.go
index 3fb4cead0b..fe0affceda 100644
--- a/internal/checker/printer.go
+++ b/internal/checker/printer.go
@@ -182,7 +182,7 @@ func (c *Checker) typeToStringEx(t *Type, enclosingDeclaration *ast.Node, flags
 	if noTruncation {
 		combinedFlags = combinedFlags | nodebuilder.FlagsNoTruncation
 	}
-	nodeBuilder := c.GetNodeBuilder()
+	nodeBuilder := c.getNodeBuilder()
 	typeNode := nodeBuilder.TypeToTypeNode(t, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
 	if typeNode == nil {
 		panic("should always get typenode")
@@ -246,7 +246,7 @@ func (c *Checker) symbolToStringEx(symbol *ast.Symbol, enclosingDeclaration *ast
 		internalNodeFlags |= nodebuilder.InternalFlagsWriteComputedProps
 	}
 
-	nodeBuilder := c.GetNodeBuilder()
+	nodeBuilder := c.getNodeBuilder()
 	var sourceFile *ast.SourceFile
 	if enclosingDeclaration != nil {
 		sourceFile = ast.GetSourceFileOfNode(enclosingDeclaration)
@@ -296,7 +296,7 @@ func (c *Checker) signatureToStringEx(signature *Signature, enclosingDeclaration
 	writer, putWriter := printer.GetSingleLineStringWriter()
 	defer putWriter()
 
-	nodeBuilder := c.GetNodeBuilder()
+	nodeBuilder := c.getNodeBuilder()
 	combinedFlags := toNodeBuilderFlags(flags) | nodebuilder.FlagsIgnoreErrors | nodebuilder.FlagsWriteTypeParametersInQualifiedName
 	sig := nodeBuilder.SignatureToSignatureDeclaration(signature, sigOutput, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil)
 	printer_ := createPrinterWithRemoveCommentsOmitTrailingSemicolon(nodeBuilder.EmitContext())
@@ -315,7 +315,7 @@ func (c *Checker) typePredicateToString(typePredicate *TypePredicate) string {
 func (c *Checker) typePredicateToStringEx(typePredicate *TypePredicate, enclosingDeclaration *ast.Node, flags TypeFormatFlags) string {
 	writer, putWriter := printer.GetSingleLineStringWriter()
 	defer putWriter()
-	nodeBuilder := c.GetNodeBuilder()
+	nodeBuilder := c.getNodeBuilder()
 	combinedFlags := toNodeBuilderFlags(flags) | nodebuilder.FlagsIgnoreErrors | nodebuilder.FlagsWriteTypeParametersInQualifiedName
 	predicate := nodeBuilder.TypePredicateToTypePredicateNode(typePredicate, enclosingDeclaration, combinedFlags, nodebuilder.InternalFlagsNone, nil) // TODO: GH#18217
 	printer_ := createPrinterWithRemoveComments(nodeBuilder.EmitContext())

From bee631ed33b2b1370c9e079167675c7993f132fc Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Thu, 26 Jun 2025 15:40:43 -0700
Subject: [PATCH 9/9] Undo reuse change, sad

---
 internal/checker/checker.go     | 5 -----
 internal/checker/nodebuilder.go | 6 ------
 2 files changed, 11 deletions(-)

diff --git a/internal/checker/checker.go b/internal/checker/checker.go
index 3962b04717..6edc56adf4 100644
--- a/internal/checker/checker.go
+++ b/internal/checker/checker.go
@@ -848,8 +848,6 @@ type Checker struct {
 	markNodeAssignments                         func(*ast.Node) bool
 	emitResolver                                *emitResolver
 	emitResolverOnce                            sync.Once
-	inCheckSourceFile                           bool
-	nodeBuilderDuringCheckSourceFile            *NodeBuilder
 	_jsxNamespace                               string
 	_jsxFactoryEntity                           *ast.Node
 	skipDirectInferenceNodes                    collections.Set[*ast.Node]
@@ -2112,7 +2110,6 @@ func (c *Checker) checkSourceFile(ctx context.Context, sourceFile *ast.SourceFil
 	links := c.sourceFileLinks.Get(sourceFile)
 	if !links.typeChecked {
 		c.ctx = ctx
-		c.inCheckSourceFile = true
 		// Grammar checking
 		c.checkGrammarSourceFile(sourceFile)
 		c.renamedBindingElementsInTypes = nil
@@ -2135,8 +2132,6 @@ func (c *Checker) checkSourceFile(ctx context.Context, sourceFile *ast.SourceFil
 			c.wasCanceled = true
 		}
 		c.ctx = nil
-		c.inCheckSourceFile = false
-		c.nodeBuilderDuringCheckSourceFile = nil
 		links.typeChecked = true
 	}
 }
diff --git a/internal/checker/nodebuilder.go b/internal/checker/nodebuilder.go
index 41c4b22235..b6be4efda6 100644
--- a/internal/checker/nodebuilder.go
+++ b/internal/checker/nodebuilder.go
@@ -171,11 +171,5 @@ func NewNodeBuilder(ch *Checker, e *printer.EmitContext) *NodeBuilder {
 }
 
 func (c *Checker) getNodeBuilder() *NodeBuilder {
-	if c.inCheckSourceFile {
-		if c.nodeBuilderDuringCheckSourceFile == nil {
-			c.nodeBuilderDuringCheckSourceFile = NewNodeBuilder(c, printer.NewEmitContext())
-		}
-		return c.nodeBuilderDuringCheckSourceFile
-	}
 	return NewNodeBuilder(c, printer.NewEmitContext())
 }