Make sure the script is only attached to project during createProgram execution

src/server/project.ts

@@ -713,7 +713,11 @@ export abstract class Project implements LanguageServiceHost, ModuleResolutionHo
                 // This was missing path earlier but now the file exists. Update the root
                 existingValue.info = scriptInfo;
             }
-            scriptInfo.attachToProject(this);
+            // Make sure the script is only attached to project during createProgram execution
+            const creatingProgram = !this.languageService.getCurrentProgram(/*acceptOutdatedProgram*/ false);
+            if (creatingProgram) {
+                scriptInfo.attachToProject(this);
+            }
         }
         return scriptInfo;
     }

src/services/services.ts

@@ -1633,6 +1633,7 @@ export function createLanguageService(
 
     const syntaxTreeCache: SyntaxTreeCache = new SyntaxTreeCache(host);
     let program: Program;
+    let creatingProgram = false;
     let lastProjectVersion: string;
     let lastTypesRootVersion = 0;
 
@@ -1816,7 +1817,9 @@ export function createLanguageService(
             oldProgram: program,
             projectReferences,
         };
+        creatingProgram = true;
         program = createProgram(options);
+        creatingProgram = false;
 
         // 'getOrCreateSourceFile' depends on caching but should be used past this point.
         // After this point, the cache needs to be cleared to allow all collected snapshots to be released
@@ -3396,7 +3399,12 @@ export function createLanguageService(
         getEmitOutput,
         getNonBoundSourceFile,
         getProgram,
-        getCurrentProgram: () => program,
+        getCurrentProgram: (acceptOutdatedProgram = true) => {
+            if (!acceptOutdatedProgram && creatingProgram) {
+                return undefined;
+            }
+            return program;
+        },
         getAutoImportProvider,
         updateIsDefinitionOfReferencedSymbols,
         getApplicableRefactors,

src/services/types.ts

@@ -679,7 +679,7 @@ export interface LanguageService {
     getEmitOutput(fileName: string, emitOnlyDtsFiles?: boolean, forceDtsEmit?: boolean): EmitOutput;
 
     getProgram(): Program | undefined;
-    /** @internal */ getCurrentProgram(): Program | undefined;
+    /** @internal */ getCurrentProgram(acceptOutdatedProgram?: boolean): Program | undefined;
 
     /** @internal */ getNonBoundSourceFile(fileName: string): SourceFile;
     /** @internal */ getAutoImportProvider(): Program | undefined;