Fix implied formats, file watching, new source file creating during edits

src/compiler/diagnosticMessages.json

@@ -1464,6 +1464,22 @@
         "category": "Message",
         "code": 1457
     },
+    "File is ECMAScript module because '{0}' has field \"type\" with value \"module\"": {
+        "category": "Message",
+        "code": 1458
+    },
+    "File is CommonJS module because '{0}' has field \"type\" whose value is not \"module\"": {
+        "category": "Message",
+        "code": 1459
+    },
+    "File is CommonJS module because '{0}' does not have field \"type\"": {
+        "category": "Message",
+        "code": 1460
+    },
+    "File is CommonJS module because 'package.json' was not found": {
+        "category": "Message",
+        "code": 1461
+    },
 
     "The 'import.meta' meta-property is not allowed in files which will build into CommonJS output.": {
         "category": "Error",

src/compiler/moduleNameResolver.ts

@@ -543,6 +543,7 @@ namespace ts {
     }
 
     export interface TypeReferenceDirectiveResolutionCache extends PerDirectoryResolutionCache<ResolvedTypeReferenceDirectiveWithFailedLookupLocations>, PackageJsonInfoCache {
+        /*@internal*/ clearAllExceptPackageJsonInfoCache(): void;
     }
 
     export interface ModeAwareCache<T> {
@@ -570,6 +571,7 @@ namespace ts {
 
     export interface ModuleResolutionCache extends PerDirectoryResolutionCache<ResolvedModuleWithFailedLookupLocations>, NonRelativeModuleNameResolutionCache, PackageJsonInfoCache {
         getPackageJsonInfoCache(): PackageJsonInfoCache;
+        /*@internal*/ clearAllExceptPackageJsonInfoCache(): void;
     }
 
     /**
@@ -584,6 +586,7 @@ namespace ts {
         /*@internal*/ getPackageJsonInfo(packageJsonPath: string): PackageJsonInfo | boolean | undefined;
         /*@internal*/ setPackageJsonInfo(packageJsonPath: string, info: PackageJsonInfo | boolean): void;
         /*@internal*/ entries(): [Path, PackageJsonInfo | boolean][];
+        /*@internal*/ getInternalMap(): ESMap<Path, PackageJsonInfo | boolean> | undefined;
         clear(): void;
     }
 
@@ -649,7 +652,7 @@ namespace ts {
 
     function createPackageJsonInfoCache(currentDirectory: string, getCanonicalFileName: (s: string) => string): PackageJsonInfoCache {
         let cache: ESMap<Path, PackageJsonInfo | boolean> | undefined;
-        return { getPackageJsonInfo, setPackageJsonInfo, clear, entries };
+        return { getPackageJsonInfo, setPackageJsonInfo, clear, entries, getInternalMap };
         function getPackageJsonInfo(packageJsonPath: string) {
             return cache?.get(toPath(packageJsonPath, currentDirectory, getCanonicalFileName));
         }
@@ -663,6 +666,9 @@ namespace ts {
             const iter = cache?.entries();
             return iter ? arrayFrom(iter) : [];
         }
+        function getInternalMap() {
+            return cache;
+        }
     }
 
     function getOrCreateCache<T>(cacheWithRedirects: CacheWithRedirects<T>, redirectedReference: ResolvedProjectReference | undefined, key: string, create: () => T): T {
@@ -797,25 +803,30 @@ namespace ts {
         directoryToModuleNameMap?: CacheWithRedirects<ModeAwareCache<ResolvedModuleWithFailedLookupLocations>>,
         moduleNameToDirectoryMap?: CacheWithRedirects<PerModuleNameCache>,
     ): ModuleResolutionCache {
-        const preDirectoryResolutionCache = createPerDirectoryResolutionCache(currentDirectory, getCanonicalFileName, directoryToModuleNameMap ||= createCacheWithRedirects(options));
+        const perDirectoryResolutionCache = createPerDirectoryResolutionCache(currentDirectory, getCanonicalFileName, directoryToModuleNameMap ||= createCacheWithRedirects(options));
         moduleNameToDirectoryMap ||= createCacheWithRedirects(options);
         const packageJsonInfoCache = createPackageJsonInfoCache(currentDirectory, getCanonicalFileName);
 
         return {
             ...packageJsonInfoCache,
-            ...preDirectoryResolutionCache,
+            ...perDirectoryResolutionCache,
             getOrCreateCacheForModuleName,
             clear,
             update,
             getPackageJsonInfoCache: () => packageJsonInfoCache,
+            clearAllExceptPackageJsonInfoCache,
         };
 
         function clear() {
-            preDirectoryResolutionCache.clear();
-            moduleNameToDirectoryMap!.clear();
+            clearAllExceptPackageJsonInfoCache();
             packageJsonInfoCache.clear();
         }
 
+        function clearAllExceptPackageJsonInfoCache() {
+            perDirectoryResolutionCache.clear();
+            moduleNameToDirectoryMap!.clear();
+        }
+
         function update(options: CompilerOptions) {
             updateRedirectsMap(options, directoryToModuleNameMap!, moduleNameToDirectoryMap);
         }
@@ -926,12 +937,17 @@ namespace ts {
             ...packageJsonInfoCache,
             ...preDirectoryResolutionCache,
             clear,
+            clearAllExceptPackageJsonInfoCache,
         };
 
         function clear() {
-            preDirectoryResolutionCache.clear();
+            clearAllExceptPackageJsonInfoCache();
             packageJsonInfoCache!.clear();
         }
+
+        function clearAllExceptPackageJsonInfoCache() {
+            preDirectoryResolutionCache.clear();
+        }
     }
 
     export function resolveModuleNameFromCache(moduleName: string, containingFile: string, cache: ModuleResolutionCache, mode?: ModuleKind.CommonJS | ModuleKind.ESNext): ResolvedModuleWithFailedLookupLocations | undefined {

src/compiler/parser.ts

@@ -746,6 +746,8 @@ namespace ts {
          * check specified by `isFileProbablyExternalModule` will be used to set the field.
          */
         setExternalModuleIndicator?: (file: SourceFile) => void;
+        /*@internal*/ packageJsonLocations?: readonly string[];
+        /*@internal*/ packageJsonScope?: ReturnType<typeof getPackageScopeForPath>;
     }
 
     function setExternalModuleIndicator(sourceFile: SourceFile) {