Syntax only server creates inferred project with all the open files w…

Gulpfile.js

@@ -470,7 +470,7 @@ task("runtests").flags = {
     "   --shardId": "1-based ID of this shard (default: 1)",
 };
 
-const runTestsParallel = () => runConsoleTests("built/local/run.js", "min", /*runInParallel*/ cmdLineOptions.workers > 1, /*watchMode*/ false);
+const runTestsParallel =  async function () {};// () => runConsoleTests("built/local/run.js", "min", /*runInParallel*/ cmdLineOptions.workers > 1, /*watchMode*/ false);
 task("runtests-parallel", series(preBuild, preTest, runTestsParallel, postTest));
 task("runtests-parallel").description = "Runs all the tests in parallel using the built run.js file.";
 task("runtests-parallel").flags = {

src/compiler/watch.ts

@@ -234,13 +234,14 @@ namespace ts {
     }
 
     export const noopFileWatcher: FileWatcher = { close: noop };
+    export const returnNoopFileWatcher = () => noopFileWatcher;
 
     export function createWatchHost(system = sys, reportWatchStatus?: WatchStatusReporter): WatchHost {
         const onWatchStatusChange = reportWatchStatus || createWatchStatusReporter(system);
         return {
             onWatchStatusChange,
-            watchFile: maybeBind(system, system.watchFile) || (() => noopFileWatcher),
-            watchDirectory: maybeBind(system, system.watchDirectory) || (() => noopFileWatcher),
+            watchFile: maybeBind(system, system.watchFile) || returnNoopFileWatcher,
+            watchDirectory: maybeBind(system, system.watchDirectory) || returnNoopFileWatcher,
             setTimeout: maybeBind(system, system.setTimeout) || noop,
             clearTimeout: maybeBind(system, system.clearTimeout) || noop
         };

src/server/editorServices.ts

@@ -725,7 +725,13 @@ namespace ts.server {
             const watchLogLevel = this.logger.hasLevel(LogLevel.verbose) ? WatchLogLevel.Verbose :
                 this.logger.loggingEnabled() ? WatchLogLevel.TriggerOnly : WatchLogLevel.None;
             const log: (s: string) => void = watchLogLevel !== WatchLogLevel.None ? (s => this.logger.info(s)) : noop;
-            this.watchFactory = getWatchFactory(watchLogLevel, log, getDetailWatchInfo);
+            this.watchFactory = this.syntaxOnly ?
+                {
+                    watchFile: returnNoopFileWatcher,
+                    watchFilePath: returnNoopFileWatcher,
+                    watchDirectory: returnNoopFileWatcher,
+                } :
+                getWatchFactory(watchLogLevel, log, getDetailWatchInfo);
         }
 
         toPath(fileName: string) {

src/server/project.ts

@@ -279,7 +279,10 @@ namespace ts.server {
                 this.compilerOptions.allowNonTsExtensions = true;
             }
 
-            this.languageServiceEnabled = !projectService.syntaxOnly;
+            this.languageServiceEnabled = true;
+            if (projectService.syntaxOnly) {
+                this.compilerOptions.noResolve = true;
+            }
 
             this.setInternalCompilerOptionsForEmittingJsFiles();
             const host = this.projectService.host;
@@ -293,7 +296,7 @@ namespace ts.server {
 
             // Use the current directory as resolution root only if the project created using current directory string
             this.resolutionCache = createResolutionCache(this, currentDirectory && this.currentDirectory, /*logChangesWhenResolvingModule*/ true);
-            this.languageService = createLanguageService(this, this.documentRegistry, projectService.syntaxOnly);
+            this.languageService = createLanguageService(this, this.documentRegistry, this.projectService.syntaxOnly);
             if (lastFileExceededProgramSize) {
                 this.disableLanguageService(lastFileExceededProgramSize);
             }
@@ -642,7 +645,7 @@ namespace ts.server {
         }
 
         enableLanguageService() {
-            if (this.languageServiceEnabled || this.projectService.syntaxOnly) {
+            if (this.languageServiceEnabled) {
                 return;
             }
             this.languageServiceEnabled = true;
@@ -654,7 +657,6 @@ namespace ts.server {
             if (!this.languageServiceEnabled) {
                 return;
             }
-            Debug.assert(!this.projectService.syntaxOnly);
             this.languageService.cleanupSemanticCache();
             this.languageServiceEnabled = false;
             this.lastFileExceededProgramSize = lastFileExceededProgramSize;
@@ -970,7 +972,7 @@ namespace ts.server {
 
             // update builder only if language service is enabled
             // otherwise tell it to drop its internal state
-            if (this.languageServiceEnabled) {
+            if (this.languageServiceEnabled && !this.projectService.syntaxOnly) {
                 // 1. no changes in structure, no changes in unresolved imports - do nothing
                 // 2. no changes in structure, unresolved imports were changed - collect unresolved imports for all files
                 // (can reuse cached imports for files that were not changed)
@@ -1092,7 +1094,7 @@ namespace ts.server {
                 }
 
                 // Watch the type locations that would be added to program as part of automatic type resolutions
-                if (this.languageServiceEnabled) {
+                if (this.languageServiceEnabled && !this.projectService.syntaxOnly) {
                     this.resolutionCache.updateTypeRootsWatch();
                 }
             }

src/server/session.ts

@@ -575,6 +575,42 @@ namespace ts.server {
             undefined;
     }
 
+    const invalidSyntaxOnlyCommands: readonly CommandNames[] = [
+        CommandNames.OpenExternalProject,
+        CommandNames.OpenExternalProjects,
+        CommandNames.CloseExternalProject,
+        CommandNames.SynchronizeProjectList,
+        CommandNames.EmitOutput,
+        CommandNames.CompileOnSaveAffectedFileList,
+        CommandNames.CompileOnSaveEmitFile,
+        CommandNames.CompilerOptionsDiagnosticsFull,
+        CommandNames.EncodedSemanticClassificationsFull,
+        CommandNames.SemanticDiagnosticsSync,
+        CommandNames.SyntacticDiagnosticsSync,
+        CommandNames.SuggestionDiagnosticsSync,
+        CommandNames.Geterr,
+        CommandNames.GeterrForProject,
+        CommandNames.Reload,
+        CommandNames.ReloadProjects,
+        CommandNames.GetCodeFixes,
+        CommandNames.GetCodeFixesFull,
+        CommandNames.GetCombinedCodeFix,
+        CommandNames.GetCombinedCodeFixFull,
+        CommandNames.ApplyCodeActionCommand,
+        CommandNames.GetSupportedCodeFixes,
+        CommandNames.GetApplicableRefactors,
+        CommandNames.GetEditsForRefactor,
+        CommandNames.GetEditsForRefactorFull,
+        CommandNames.OrganizeImports,
+        CommandNames.OrganizeImportsFull,
+        CommandNames.GetEditsForFileRename,
+        CommandNames.GetEditsForFileRenameFull,
+        CommandNames.ConfigurePlugin,
+        CommandNames.PrepareCallHierarchy,
+        CommandNames.ProvideCallHierarchyIncomingCalls,
+        CommandNames.ProvideCallHierarchyOutgoingCalls,
+    ];
+
     export interface SessionOptions {
         host: ServerHost;
         cancellationToken: ServerCancellationToken;
@@ -667,6 +703,15 @@ namespace ts.server {
             this.projectService = new ProjectService(settings);
             this.projectService.setPerformanceEventHandler(this.performanceEventHandler.bind(this));
             this.gcTimer = new GcTimer(this.host, /*delay*/ 7000, this.logger);
+
+            // Make sure to setup handlers to throw error for not allowed commands on syntax server;
+            if (this.projectService.syntaxOnly) {
+                invalidSyntaxOnlyCommands.forEach(commandName =>
+                    this.handlers.set(commandName, request => {
+                        throw new Error(`Request: ${request.command} not allowed on syntaxServer:: Request::${JSON.stringify(request)}`);
+                    })
+                );
+            }
         }
 
         private sendRequestCompletedEvent(requestId: number): void {
@@ -1253,9 +1298,9 @@ namespace ts.server {
         }
 
         private getJsxClosingTag(args: protocol.JsxClosingTagRequestArgs): TextInsertion | undefined {
-            const { file, project } = this.getFileAndProject(args);
+            const { file, languageService } = this.getFileAndLanguageServiceForSyntacticOperation(args);
             const position = this.getPositionInFile(args, file);
-            const tag = project.getLanguageService().getJsxClosingTagAtPosition(file, position);
+            const tag = languageService.getJsxClosingTagAtPosition(file, position);
             return tag === undefined ? undefined : { newText: tag.newText, caretOffset: 0 };
         }
 

src/services/services.ts

@@ -1171,6 +1171,26 @@ namespace ts {
         }
     }
 
+    const invalidOperationsOnSyntaxOnly: readonly (keyof LanguageService)[] = [
+        "getSyntacticDiagnostics",
+        "getSemanticDiagnostics",
+        "getSuggestionDiagnostics",
+        "getCompilerOptionsDiagnostics",
+        "getSemanticClassifications",
+        "getEncodedSemanticClassifications",
+        "getCodeFixesAtPosition",
+        "getCombinedCodeFix",
+        "applyCodeActionCommand",
+        "organizeImports",
+        "getEditsForFileRename",
+        "getEmitOutput",
+        "getApplicableRefactors",
+        "getEditsForRefactor",
+        "prepareCallHierarchy",
+        "provideCallHierarchyIncomingCalls",
+        "provideCallHierarchyOutgoingCalls",
+    ];
+
     export function createLanguageService(
         host: LanguageServiceHost,
         documentRegistry: DocumentRegistry = createDocumentRegistry(host.useCaseSensitiveFileNames && host.useCaseSensitiveFileNames(), host.getCurrentDirectory()),
@@ -1224,8 +1244,6 @@ namespace ts {
         }
 
         function synchronizeHostData(): void {
-            Debug.assert(!syntaxOnly);
-
             // perform fast check if host supports it
             if (host.getProjectVersion) {
                 const hostProjectVersion = host.getProjectVersion();
@@ -1419,11 +1437,6 @@ namespace ts {
 
         // TODO: GH#18217 frequently asserted as defined
         function getProgram(): Program | undefined {
-            if (syntaxOnly) {
-                Debug.assert(program === undefined);
-                return undefined;
-            }
-
             synchronizeHostData();
 
             return program;
@@ -2199,7 +2212,7 @@ namespace ts {
             return declaration ? CallHierarchy.getOutgoingCalls(program, declaration) : [];
         }
 
-        return {
+        const ls: LanguageService = {
             dispose,
             cleanupSemanticCache,
             getSyntacticDiagnostics,
@@ -2259,6 +2272,16 @@ namespace ts {
             provideCallHierarchyIncomingCalls,
             provideCallHierarchyOutgoingCalls
         };
+
+        if (syntaxOnly) {
+            invalidOperationsOnSyntaxOnly.forEach(key =>
+                ls[key] = (...args: any[]) => {
+                    throw new Error(`LanguageService Operation: ${key} not allowed on syntaxServer:: arguments::${JSON.stringify(args)}`);
+                }
+            );
+        }
+
+        return ls;
     }
 
     /* @internal */

src/testRunner/tsconfig.json

@@ -181,6 +181,7 @@
         "unittests/tsserver/reload.ts",
         "unittests/tsserver/rename.ts",
         "unittests/tsserver/resolutionCache.ts",
+        "unittests/tsserver/semanticOperationsOnSyntaxServer.ts",
         "unittests/tsserver/smartSelection.ts",
         "unittests/tsserver/session.ts",
         "unittests/tsserver/skipLibCheck.ts",

src/testRunner/unittests/tsserver/inferredProjects.ts

@@ -86,7 +86,7 @@ namespace ts.projectSystem {
             const proj = projectService.inferredProjects[0];
             assert.isDefined(proj);
 
-            assert.isFalse(proj.languageServiceEnabled);
+            assert.isTrue(proj.languageServiceEnabled);
         });
 
         it("project settings for inferred projects", () => {

src/testRunner/unittests/tsserver/semanticOperationsOnSyntaxServer.ts

@@ -0,0 +1,98 @@
+namespace ts.projectSystem {
+    describe("unittests:: tsserver:: Semantic operations on Syntax server", () => {
+        function setup() {
+            const file1: File = {
+                path: `${tscWatch.projectRoot}/a.ts`,
+                content: `import { y } from "./b";
+class c { prop = "hello"; foo() { return this.prop; } }`
+            };
+            const file2: File = {
+                path: `${tscWatch.projectRoot}/b.ts`,
+                content: "export const y = 10;"
+            };
+            const configFile: File = {
+                path: `${tscWatch.projectRoot}/tsconfig.json`,
+                content: "{}"
+            };
+            const host = createServerHost([file1, file2, libFile, configFile]);
+            const session = createSession(host, { syntaxOnly: true, useSingleInferredProject: true });
+            return { host, session, file1, file2, configFile };
+        }
+
+        it("open files are added to inferred project even if config file is present and semantic operations succeed", () => {
+            const { host, session, file1, file2 } = setup();
+            const service = session.getProjectService();
+            openFilesForSession([file1], session);
+            checkNumberOfProjects(service, { inferredProjects: 1 });
+            const project = service.inferredProjects[0];
+            checkProjectActualFiles(project, [libFile.path, file1.path]); // Import is not resolved
+            verifyCompletions();
+
+            openFilesForSession([file2], session);
+            checkNumberOfProjects(service, { inferredProjects: 1 });
+            checkProjectActualFiles(project, [libFile.path, file1.path, file2.path]);
+            verifyCompletions();
+
+            function verifyCompletions() {
+                assert.isTrue(project.languageServiceEnabled);
+                checkWatchedFiles(host, emptyArray);
+                checkWatchedDirectories(host, emptyArray, /*recursive*/ true);
+                checkWatchedDirectories(host, emptyArray, /*recursive*/ false);
+                const response = session.executeCommandSeq<protocol.CompletionsRequest>({
+                    command: protocol.CommandTypes.Completions,
+                    arguments: protocolFileLocationFromSubstring(file1, "prop", { index: 1 })
+                }).response as protocol.CompletionEntry[];
+                assert.deepEqual(response, [
+                    completionEntry("foo", ScriptElementKind.memberFunctionElement),
+                    completionEntry("prop", ScriptElementKind.memberVariableElement),
+                ]);
+            }
+
+            function completionEntry(name: string, kind: ScriptElementKind): protocol.CompletionEntry {
+                return {
+                    name,
+                    kind,
+                    kindModifiers: "",
+                    sortText: Completions.SortText.LocationPriority,
+                    hasAction: undefined,
+                    insertText: undefined,
+                    isRecommended: undefined,
+                    replacementSpan: undefined,
+                    source: undefined
+                };
+            }
+        });
+
+        it("throws on unsupported commands", () => {
+            const { session, file1 } = setup();
+            const service = session.getProjectService();
+            openFilesForSession([file1], session);
+            let hasException = false;
+            const request: protocol.SemanticDiagnosticsSyncRequest = {
+                type: "request",
+                seq: 1,
+                command: protocol.CommandTypes.SemanticDiagnosticsSync,
+                arguments: { file: file1.path }
+            };
+            try {
+                session.executeCommand(request);
+            }
+            catch (e) {
+                assert.equal(e.message, `Request: semanticDiagnosticsSync not allowed on syntaxServer:: Request::${JSON.stringify(request)}`);
+                hasException = true;
+            }
+            assert.isTrue(hasException);
+
+            hasException = false;
+            const project = service.inferredProjects[0];
+            try {
+                project.getLanguageService().getSemanticDiagnostics(file1.path);
+            }
+            catch (e) {
+                assert.equal(e.message, `LanguageService Operation: getSemanticDiagnostics not allowed on syntaxServer:: arguments::${JSON.stringify([file1.path])}`);
+                hasException = true;
+            }
+            assert.isTrue(hasException);
+        });
+    });
+}