Refactor: move shouldRewriteModuleSpecifier to core package

Co-authored-by: andrewbranch <3277153+andrewbranch@users.noreply.github.com>

Author: Copilot

internal/checker/checker.go

@@ -14503,7 +14503,7 @@ func (c *Checker) resolveExternalModule(location *ast.Node, moduleReference stri
 				!tspath.IsDeclarationFileName(moduleReference) &&
 				!ast.IsLiteralImportTypeNode(location) &&
 				!ast.IsPartOfTypeOnlyImportOrExportDeclaration(location) {
-				shouldRewrite := c.shouldRewriteModuleSpecifier(moduleReference)
+				shouldRewrite := core.ShouldRewriteModuleSpecifier(moduleReference, c.compilerOptions)
 				if !resolvedModule.ResolvedUsingTsExtension && shouldRewrite {
 					relativeToSourceFile := tspath.GetRelativePathFromFile(
 						tspath.GetNormalizedAbsolutePath(importingSourceFile.FileName(), c.program.GetCurrentDirectory()),
@@ -30408,10 +30408,3 @@ func (c *Checker) GetEmitResolver(file *ast.SourceFile, skipDiagnostics bool) *e
 func (c *Checker) GetAliasedSymbol(symbol *ast.Symbol) *ast.Symbol {
 	return c.resolveAlias(symbol)
 }
-
-func (c *Checker) shouldRewriteModuleSpecifier(specifier string) bool {
-	return c.compilerOptions.RewriteRelativeImportExtensions.IsTrue() &&
-		tspath.PathIsRelative(specifier) &&
-		!tspath.IsDeclarationFileName(specifier) &&
-		tspath.HasTSFileExtension(specifier)
-}

internal/core/core.go

@@ -559,3 +559,7 @@ func IndexAfter(s string, pattern string, startIndex int) int {
 		return matched + startIndex
 	}
 }
+
+func ShouldRewriteModuleSpecifier(specifier string, compilerOptions *CompilerOptions) bool {
+	return compilerOptions.RewriteRelativeImportExtensions.IsTrue() && tspath.PathIsRelative(specifier) && !tspath.IsDeclarationFileName(specifier) && tspath.HasTSFileExtension(specifier)
+}

internal/transformers/utilities.go

@@ -336,7 +336,7 @@ func tryRenameExternalModule(factory *printer.NodeFactory, moduleName *ast.Liter
 }
 
 func rewriteModuleSpecifier(emitContext *printer.EmitContext, node *ast.Expression, compilerOptions *core.CompilerOptions) *ast.Expression {
-	if node == nil || !ast.IsStringLiteral(node) || !shouldRewriteModuleSpecifier(node.Text(), compilerOptions) {
+	if node == nil || !ast.IsStringLiteral(node) || !core.ShouldRewriteModuleSpecifier(node.Text(), compilerOptions) {
 		return node
 	}
 	updatedText := tspath.ChangeExtension(node.Text(), outputpaths.GetOutputExtension(node.Text(), compilerOptions.Jsx))
@@ -350,10 +350,6 @@ func rewriteModuleSpecifier(emitContext *printer.EmitContext, node *ast.Expressi
 	return node
 }
 
-func shouldRewriteModuleSpecifier(specifier string, compilerOptions *core.CompilerOptions) bool {
-	return compilerOptions.RewriteRelativeImportExtensions.IsTrue() && tspath.PathIsRelative(specifier) && !tspath.IsDeclarationFileName(specifier) && tspath.HasTSFileExtension(specifier)
-}
-
 func singleOrMany(nodes []*ast.Node, factory *printer.NodeFactory) *ast.Node {
 	if len(nodes) == 1 {
 		return nodes[0]