Add way to handle different script kind for the source file to determine if program is upto date

Author: sheetalkamat

src/compiler/program.ts

@@ -653,6 +653,7 @@ namespace ts {
         rootFileNames: string[],
         newOptions: CompilerOptions,
         getSourceVersion: (path: Path, fileName: string) => string | undefined,
+        getScriptKind: ((path: Path, fileName: string) => ScriptKind) | undefined,
         fileExists: (fileName: string) => boolean,
         hasInvalidatedResolution: HasInvalidatedResolution,
         hasChangedAutomaticTypeDirectiveNames: HasChangedAutomaticTypeDirectiveNames | undefined,
@@ -688,13 +689,19 @@ namespace ts {
 
         function sourceFileNotUptoDate(sourceFile: SourceFile) {
             return !sourceFileVersionUptoDate(sourceFile) ||
+                !sourceFileScriptKindUptoDate(sourceFile) ||
                 hasInvalidatedResolution(sourceFile.path);
         }
 
         function sourceFileVersionUptoDate(sourceFile: SourceFile) {
             return sourceFile.version === getSourceVersion(sourceFile.resolvedPath, sourceFile.fileName);
         }
 
+        function sourceFileScriptKindUptoDate(sourceFile: SourceFile) {
+            return !getScriptKind ||
+                sourceFile.scriptKind === ensureScriptKind(sourceFile.fileName, getScriptKind(sourceFile.resolvedPath, sourceFile.fileName));
+        }
+
         function projectReferenceUptoDate(oldRef: ProjectReference, newRef: ProjectReference, index: number) {
             return projectReferenceIsEqualTo(oldRef, newRef) &&
                 resolvedProjectReferenceUptoDate(program!.getResolvedProjectReferences()![index], oldRef);

src/compiler/watchPublic.ts

@@ -426,7 +426,7 @@ namespace ts {
 
             // All resolutions are invalid if user provided resolutions
             const hasInvalidatedResolution = resolutionCache.createHasInvalidatedResolution(userProvidedResolution);
-            if (isProgramUptoDate(getCurrentProgram(), rootFileNames, compilerOptions, getSourceVersion, fileExists, hasInvalidatedResolution, hasChangedAutomaticTypeDirectiveNames, getParsedCommandLine, projectReferences)) {
+            if (isProgramUptoDate(getCurrentProgram(), rootFileNames, compilerOptions, getSourceVersion, /*getScriptKind*/ undefined, fileExists, hasInvalidatedResolution, hasChangedAutomaticTypeDirectiveNames, getParsedCommandLine, projectReferences)) {
                 if (hasChangedConfigFileParsingErrors) {
                     builderProgram = createProgram(/*rootNames*/ undefined, /*options*/ undefined, compilerHost, builderProgram, configFileParsingDiagnostics, projectReferences);
                     hasChangedConfigFileParsingErrors = false;

src/server/project.ts

@@ -412,7 +412,8 @@ namespace ts.server {
         }
 
         getScriptKind(fileName: string) {
-            const info = this.getOrCreateScriptInfoAndAttachToProject(fileName);
+            // Don't attach to the project if script kind is asked
+            const info = this.projectService.getOrCreateScriptInfoNotOpenedByClient(fileName, this.currentDirectory, this.directoryStructureHost);
             return (info && info.scriptKind)!; // TODO: GH#18217
         }
 

src/services/services.ts

@@ -1312,7 +1312,7 @@ namespace ts {
             };
 
             // If the program is already up-to-date, we can reuse it
-            if (isProgramUptoDate(program, rootFileNames, newSettings, (_path, fileName) => host.getScriptVersion(fileName), fileExists, hasInvalidatedResolution, hasChangedAutomaticTypeDirectiveNames, getParsedCommandLine, projectReferences)) {
+            if (isProgramUptoDate(program, rootFileNames, newSettings, (_path, fileName) => host.getScriptVersion(fileName), host.getScriptKind ? (_path, fileName) => host.getScriptKind!(fileName) : undefined, fileExists, hasInvalidatedResolution, hasChangedAutomaticTypeDirectiveNames, getParsedCommandLine, projectReferences)) {
                 return;
             }
 

src/testRunner/unittests/reuseProgramStructure.ts

@@ -913,7 +913,9 @@ namespace ts {
         ) {
             return isProgramUptoDate(
                 program, newRootFileNames, newOptions,
-                path => program.getSourceFileByPath(path)!.version, /*fileExists*/ returnFalse,
+                path => program.getSourceFileByPath(path)!.version,
+                /*getScfriptKind*/ undefined,
+                /*fileExists*/ returnFalse,
                 /*hasInvalidatedResolution*/ returnFalse,
                 /*hasChangedAutomaticTypeDirectiveNames*/ undefined,
                 /*getParsedCommandLine*/ returnUndefined,