Fix debug assertion failure in move to file refactor for symbols exported separately

Co-authored-by: RyanCavanaugh <[email protected]>

Author: Copilot

src/services/refactors/helpers.ts

@@ -75,25 +75,24 @@ export function addTargetFileImports(
      * but sometimes it fails because of unresolved imports from files, or when a source file is not available for the target file (in this case when creating a new file).
      * So in that case, fall back to copying the import verbatim.
      */
-    importsToCopy.forEach(([isValidTypeOnlyUseSite, declaration], symbol) => {
-        const targetSymbol = skipAlias(symbol, checker);
-        if (checker.isUnknownSymbol(targetSymbol)) {
-            importAdder.addVerbatimImport(Debug.checkDefined(declaration ?? findAncestor(symbol.declarations?.[0], isAnyImportOrRequireStatement)));
-        }
-        else if (targetSymbol.parent === undefined) {
-            Debug.assert(declaration !== undefined, "expected module symbol to have a declaration");
-            const aliasedSymbol = checker.getAliasedSymbol(symbol);
-            if (aliasedSymbol.flags & SymbolFlags.Module) {
-                importAdder.addImportForModuleSymbol(symbol, isValidTypeOnlyUseSite, declaration);
-            }
-            else {
-                // If the aliased symbol is not a module, fall back to verbatim import
-                importAdder.addVerbatimImport(Debug.checkDefined(declaration ?? findAncestor(symbol.declarations?.[0], isAnyImportOrRequireStatement)));
-            }
-        }
-        else {
-            importAdder.addImportFromExportedSymbol(targetSymbol, isValidTypeOnlyUseSite, declaration);
-        }
+    importsToCopy.forEach(([isValidTypeOnlyUseSite, declaration], symbol) => {
+        const targetSymbol = skipAlias(symbol, checker);
+        if (checker.isUnknownSymbol(targetSymbol)) {
+            importAdder.addVerbatimImport(Debug.checkDefined(declaration ?? findAncestor(symbol.declarations?.[0], isAnyImportOrRequireStatement)));
+        }
+        else if (targetSymbol.parent === undefined) {
+            if (targetSymbol.flags & SymbolFlags.Module) {
+                Debug.assert(declaration !== undefined, "expected module symbol to have a declaration");
+                importAdder.addImportForModuleSymbol(symbol, isValidTypeOnlyUseSite, declaration);
+            }
+            else {
+                // If the target symbol has no parent but isn't a module, fall back to verbatim import
+                importAdder.addVerbatimImport(Debug.checkDefined(declaration ?? findAncestor(symbol.declarations?.[0], isAnyImportOrRequireStatement)));
+            }
+        }
+        else {
+            importAdder.addImportFromExportedSymbol(targetSymbol, isValidTypeOnlyUseSite, declaration);
+        }
     });
 
     addImportsForMovedSymbols(targetFileImportsFromOldFile, oldFile.fileName, importAdder, program);

tests/cases/fourslash/moveToNewFileSymbolWithoutParent.ts

@@ -0,0 +1,27 @@
+/// <reference path='fourslash.ts' />
+
+// Test case to reproduce the debug assertion failure
+// When moving symbols that don't have a parent but aren't modules
+// This reproduces the scenario with symbols exported separately from declaration
+
+// @Filename: /lib.ts
+////const Component = function() { return "component"; };
+////export { Component };
+
+// @Filename: /main.ts
+////import { Component } from "./lib";
+////[|function useComponent() {
+////    return Component();
+////}|]
+
+verify.moveToNewFile({
+    newFileContents: {
+        "/main.ts": ``,
+        "/useComponent.ts": `import { Component } from "./lib";
+
+function useComponent() {
+    return Component();
+}
+`
+    }
+});