diff --git a/lib/tsc.js b/lib/tsc.js
index 5deb6914e51..15e9273877a 100644
--- a/lib/tsc.js
+++ b/lib/tsc.js
@@ -24064,14 +24064,15 @@ var ts;
             }
             function symbolToParameterDeclaration(parameterSymbol, context, preserveModifierFlags) {
                 var parameterDeclaration = ts.getDeclarationOfKind(parameterSymbol, 148);
-                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol) && !!parameterSymbol.isRestParameter);
+                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol));
                 var parameterType = getTypeOfSymbol(parameterSymbol);
                 if (parameterDeclaration && isRequiredInitializedParameter(parameterDeclaration)) {
                     parameterType = getOptionalType(parameterType);
                 }
                 var parameterTypeNode = typeToTypeNodeHelper(parameterType, context);
                 var modifiers = !(context.flags & 8192) && preserveModifierFlags && parameterDeclaration && parameterDeclaration.modifiers && parameterDeclaration.modifiers.map(ts.getSynthesizedClone);
-                var dotDotDotToken = !parameterDeclaration || ts.isRestParameter(parameterDeclaration) ? ts.createToken(24) : undefined;
+                var isRest = parameterDeclaration ? ts.isRestParameter(parameterDeclaration) : parameterSymbol.isRestParameter;
+                var dotDotDotToken = isRest ? ts.createToken(24) : undefined;
                 var name = parameterDeclaration
                     ? parameterDeclaration.name ?
                         parameterDeclaration.name.kind === 71 ?
diff --git a/lib/tsserver.js b/lib/tsserver.js
index 5a484bbeeca..427b048aa5a 100644
--- a/lib/tsserver.js
+++ b/lib/tsserver.js
@@ -25501,14 +25501,15 @@ var ts;
             }
             function symbolToParameterDeclaration(parameterSymbol, context, preserveModifierFlags) {
                 var parameterDeclaration = ts.getDeclarationOfKind(parameterSymbol, 148);
-                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol) && !!parameterSymbol.isRestParameter);
+                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol));
                 var parameterType = getTypeOfSymbol(parameterSymbol);
                 if (parameterDeclaration && isRequiredInitializedParameter(parameterDeclaration)) {
                     parameterType = getOptionalType(parameterType);
                 }
                 var parameterTypeNode = typeToTypeNodeHelper(parameterType, context);
                 var modifiers = !(context.flags & 8192) && preserveModifierFlags && parameterDeclaration && parameterDeclaration.modifiers && parameterDeclaration.modifiers.map(ts.getSynthesizedClone);
-                var dotDotDotToken = !parameterDeclaration || ts.isRestParameter(parameterDeclaration) ? ts.createToken(24) : undefined;
+                var isRest = parameterDeclaration ? ts.isRestParameter(parameterDeclaration) : parameterSymbol.isRestParameter;
+                var dotDotDotToken = isRest ? ts.createToken(24) : undefined;
                 var name = parameterDeclaration
                     ? parameterDeclaration.name ?
                         parameterDeclaration.name.kind === 71 ?
@@ -94560,7 +94561,7 @@ var ts;
                 return { configFileName: configFileName, configFileErrors: configFileErrors };
             };
             ProjectService.prototype.telemetryOnOpenFile = function (scriptInfo) {
-                if (!this.eventHandler || !scriptInfo.isJavaScript() || !ts.addToSeen(this.allJsFilesForOpenFileTelemetry, scriptInfo.path)) {
+                if (this.syntaxOnly || !this.eventHandler || !scriptInfo.isJavaScript() || !ts.addToSeen(this.allJsFilesForOpenFileTelemetry, scriptInfo.path)) {
                     return;
                 }
                 var info = { checkJs: !!scriptInfo.getDefaultProject().getSourceFile(scriptInfo.path).checkJsDirective };
diff --git a/lib/tsserverlibrary.js b/lib/tsserverlibrary.js
index 74de8471c41..a3b09d06f3b 100644
--- a/lib/tsserverlibrary.js
+++ b/lib/tsserverlibrary.js
@@ -29632,14 +29632,15 @@ var ts;
             }
             function symbolToParameterDeclaration(parameterSymbol, context, preserveModifierFlags) {
                 var parameterDeclaration = ts.getDeclarationOfKind(parameterSymbol, 148 /* Parameter */);
-                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol) && !!parameterSymbol.isRestParameter);
+                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol));
                 var parameterType = getTypeOfSymbol(parameterSymbol);
                 if (parameterDeclaration && isRequiredInitializedParameter(parameterDeclaration)) {
                     parameterType = getOptionalType(parameterType);
                 }
                 var parameterTypeNode = typeToTypeNodeHelper(parameterType, context);
                 var modifiers = !(context.flags & 8192 /* OmitParameterModifiers */) && preserveModifierFlags && parameterDeclaration && parameterDeclaration.modifiers && parameterDeclaration.modifiers.map(ts.getSynthesizedClone);
-                var dotDotDotToken = !parameterDeclaration || ts.isRestParameter(parameterDeclaration) ? ts.createToken(24 /* DotDotDotToken */) : undefined;
+                var isRest = parameterDeclaration ? ts.isRestParameter(parameterDeclaration) : parameterSymbol.isRestParameter;
+                var dotDotDotToken = isRest ? ts.createToken(24 /* DotDotDotToken */) : undefined;
                 var name = parameterDeclaration
                     ? parameterDeclaration.name ?
                         parameterDeclaration.name.kind === 71 /* Identifier */ ?
@@ -112961,7 +112962,7 @@ var ts;
                 return { configFileName: configFileName, configFileErrors: configFileErrors };
             };
             ProjectService.prototype.telemetryOnOpenFile = function (scriptInfo) {
-                if (!this.eventHandler || !scriptInfo.isJavaScript() || !ts.addToSeen(this.allJsFilesForOpenFileTelemetry, scriptInfo.path)) {
+                if (this.syntaxOnly || !this.eventHandler || !scriptInfo.isJavaScript() || !ts.addToSeen(this.allJsFilesForOpenFileTelemetry, scriptInfo.path)) {
                     return;
                 }
                 var info = { checkJs: !!scriptInfo.getDefaultProject().getSourceFile(scriptInfo.path).checkJsDirective };
diff --git a/lib/typescript.js b/lib/typescript.js
index e52f70dd527..68f66dc8dca 100644
--- a/lib/typescript.js
+++ b/lib/typescript.js
@@ -29632,14 +29632,15 @@ var ts;
             }
             function symbolToParameterDeclaration(parameterSymbol, context, preserveModifierFlags) {
                 var parameterDeclaration = ts.getDeclarationOfKind(parameterSymbol, 148 /* Parameter */);
-                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol) && !!parameterSymbol.isRestParameter);
+                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol));
                 var parameterType = getTypeOfSymbol(parameterSymbol);
                 if (parameterDeclaration && isRequiredInitializedParameter(parameterDeclaration)) {
                     parameterType = getOptionalType(parameterType);
                 }
                 var parameterTypeNode = typeToTypeNodeHelper(parameterType, context);
                 var modifiers = !(context.flags & 8192 /* OmitParameterModifiers */) && preserveModifierFlags && parameterDeclaration && parameterDeclaration.modifiers && parameterDeclaration.modifiers.map(ts.getSynthesizedClone);
-                var dotDotDotToken = !parameterDeclaration || ts.isRestParameter(parameterDeclaration) ? ts.createToken(24 /* DotDotDotToken */) : undefined;
+                var isRest = parameterDeclaration ? ts.isRestParameter(parameterDeclaration) : parameterSymbol.isRestParameter;
+                var dotDotDotToken = isRest ? ts.createToken(24 /* DotDotDotToken */) : undefined;
                 var name = parameterDeclaration
                     ? parameterDeclaration.name ?
                         parameterDeclaration.name.kind === 71 /* Identifier */ ?
diff --git a/lib/typescriptServices.js b/lib/typescriptServices.js
index e52f70dd527..68f66dc8dca 100644
--- a/lib/typescriptServices.js
+++ b/lib/typescriptServices.js
@@ -29632,14 +29632,15 @@ var ts;
             }
             function symbolToParameterDeclaration(parameterSymbol, context, preserveModifierFlags) {
                 var parameterDeclaration = ts.getDeclarationOfKind(parameterSymbol, 148 /* Parameter */);
-                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol) && !!parameterSymbol.isRestParameter);
+                ts.Debug.assert(!!parameterDeclaration || isTransientSymbol(parameterSymbol));
                 var parameterType = getTypeOfSymbol(parameterSymbol);
                 if (parameterDeclaration && isRequiredInitializedParameter(parameterDeclaration)) {
                     parameterType = getOptionalType(parameterType);
                 }
                 var parameterTypeNode = typeToTypeNodeHelper(parameterType, context);
                 var modifiers = !(context.flags & 8192 /* OmitParameterModifiers */) && preserveModifierFlags && parameterDeclaration && parameterDeclaration.modifiers && parameterDeclaration.modifiers.map(ts.getSynthesizedClone);
-                var dotDotDotToken = !parameterDeclaration || ts.isRestParameter(parameterDeclaration) ? ts.createToken(24 /* DotDotDotToken */) : undefined;
+                var isRest = parameterDeclaration ? ts.isRestParameter(parameterDeclaration) : parameterSymbol.isRestParameter;
+                var dotDotDotToken = isRest ? ts.createToken(24 /* DotDotDotToken */) : undefined;
                 var name = parameterDeclaration
                     ? parameterDeclaration.name ?
                         parameterDeclaration.name.kind === 71 /* Identifier */ ?