fix: workaround for move to file refactor restriction (#2227)

prevent Svelte files from showing up in the suggestions until TypeScript allows this

packages/typescript-plugin/src/language-service/index.ts

@@ -16,6 +16,7 @@ import { decorateUpdateImports } from './update-imports';
 import { decorateLanguageServiceHost } from './host';
 import { decorateNavigateToItems } from './navigate-to-items';
 import { decorateFileReferences } from './file-references';
+import { decorateMoveToRefactoringFileSuggestions } from './move-to-file';
 
 const patchedProject = new Set<string>();
 
@@ -64,6 +65,7 @@ function decorateLanguageServiceInner(
     decorateInlayHints(ls, info, typescript, logger);
     decorateNavigateToItems(ls, snapshotManager);
     decorateFileReferences(ls, snapshotManager);
+    decorateMoveToRefactoringFileSuggestions(ls);
     decorateDispose(ls, info.project, onDispose);
     return ls;
 }

packages/typescript-plugin/src/language-service/move-to-file.ts

@@ -0,0 +1,43 @@
+import type ts from 'typescript/lib/tsserverlibrary';
+
+export function decorateMoveToRefactoringFileSuggestions(ls: ts.LanguageService): void {
+    const getMoveToRefactoringFileSuggestions = ls.getMoveToRefactoringFileSuggestions;
+
+    ls.getMoveToRefactoringFileSuggestions = (
+        fileName,
+        positionOrRange,
+        preferences,
+        triggerReason,
+        kind
+    ) => {
+        const program = ls.getProgram();
+
+        if (!program) {
+            return getMoveToRefactoringFileSuggestions(
+                fileName,
+                positionOrRange,
+                preferences,
+                triggerReason,
+                kind
+            );
+        }
+
+        const getSourceFiles = program.getSourceFiles;
+        try {
+            // typescript currently only allows js/ts files to be moved to.
+            // Once there isn't a restriction anymore, we can remove this.
+            program.getSourceFiles = () =>
+                getSourceFiles().filter((file) => !file.fileName.endsWith('.svelte'));
+
+            return getMoveToRefactoringFileSuggestions(
+                fileName,
+                positionOrRange,
+                preferences,
+                triggerReason,
+                kind
+            );
+        } finally {
+            program.getSourceFiles = getSourceFiles;
+        }
+    };
+}