Fix(54376) (#54975)

src/services/codefixes/importFixes.ts

@@ -194,7 +194,7 @@ export interface ImportAdder {
     hasFixes(): boolean;
     addImportFromDiagnostic: (diagnostic: DiagnosticWithLocation, context: CodeFixContextBase) => void;
     addImportFromExportedSymbol: (exportedSymbol: Symbol, isValidTypeOnlyUseSite?: boolean) => void;
-    writeFixes: (changeTracker: textChanges.ChangeTracker) => void;
+    writeFixes: (changeTracker: textChanges.ChangeTracker, oldFileQuotePreference?: QuotePreference) => void;
 }
 
 /** @internal */
@@ -345,8 +345,15 @@ function createImportAdderWorker(sourceFile: SourceFile, program: Program, useAu
         }
     }
 
-    function writeFixes(changeTracker: textChanges.ChangeTracker) {
-        const quotePreference = getQuotePreference(sourceFile, preferences);
+    function writeFixes(changeTracker: textChanges.ChangeTracker, oldFileQuotePreference?: QuotePreference) {
+        let quotePreference: QuotePreference;
+        if (sourceFile.imports.length === 0 && oldFileQuotePreference !== undefined) {
+            // If the target file has no imports, we must use the same quote preference as the file we are importing from.
+            quotePreference = oldFileQuotePreference;
+        }
+        else {
+            quotePreference = getQuotePreference(sourceFile, preferences);
+        }
         for (const fix of addToNamespace) {
             addNamespaceQualifier(changeTracker, sourceFile, fix);
         }

src/services/refactors/moveToFile.ts

@@ -254,7 +254,7 @@ function getNewStatementsAndRemoveFromOldFile(
         }
     }
     if (importAdder) {
-        importAdder.writeFixes(changes);
+        importAdder.writeFixes(changes, quotePreference);
     }
     if (imports.length && body.length) {
         return [

tests/cases/fourslash/moveToFile_blankExistingFile.ts

@@ -22,7 +22,7 @@ verify.moveToFile({
 import { p } from './a';
 
 
-import { b } from "./other";
+import { b } from './other';
 
 
 const y: Date = p + b;

tests/cases/fourslash/moveToFile_consistentQuoteStyle.ts

@@ -0,0 +1,36 @@
+
+/// <reference path='fourslash.ts' />
+
+// @Filename: /bar.ts
+////export const tt = 2;
+
+// @Filename: /a.ts
+////import { b } from './other';
+////const a = 1;
+////[|const c = a + b;|]
+
+// @Filename: /other.ts
+////export const b = 2;
+
+
+verify.moveToFile({
+    newFileContents: {
+        "/a.ts":
+`export const a = 1;
+`,
+
+        "/bar.ts":
+`import { a } from './a';
+
+import { b } from './other';
+
+export const tt = 2;
+const c = a + b;
+`,
+    },
+    interactiveRefactorArguments: { targetFile: "/bar.ts" },
+
+    preferences: {
+        quotePreference: "single",
+    }
+});

tests/cases/fourslash/moveToFile_differentDirectories2.ts

@@ -25,7 +25,7 @@ y;`,
         "/src/dir2/bar.ts":
 `import { a } from '../dir1/a';
 
-import { b } from "../dir1/other";
+import { b } from '../dir1/other';
 
 
 export const y = b + a;