diff --git a/tests/baselines/reference/TupleType3.errors.txt b/tests/baselines/reference/TupleType3.errors.txt
deleted file mode 100644
index a7f5b117325..00000000000
--- a/tests/baselines/reference/TupleType3.errors.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-tests/cases/conformance/parser/ecmascript5/TupleTypes/TupleType3.ts(1,8): error TS1122: A tuple type element list cannot be empty.
-
-
-==== tests/cases/conformance/parser/ecmascript5/TupleTypes/TupleType3.ts (1 errors) ====
-    var v: []
-           ~~
-!!! error TS1122: A tuple type element list cannot be empty.
\ No newline at end of file
diff --git a/tests/baselines/reference/anyIndexedAccessArrayNoException.errors.txt b/tests/baselines/reference/anyIndexedAccessArrayNoException.errors.txt
index 01c5bd6b2e2..e207468122b 100644
--- a/tests/baselines/reference/anyIndexedAccessArrayNoException.errors.txt
+++ b/tests/baselines/reference/anyIndexedAccessArrayNoException.errors.txt
@@ -1,11 +1,8 @@
-tests/cases/compiler/anyIndexedAccessArrayNoException.ts(1,12): error TS1122: A tuple type element list cannot be empty.
 tests/cases/compiler/anyIndexedAccessArrayNoException.ts(1,12): error TS2538: Type '[]' cannot be used as an index type.
 
 
-==== tests/cases/compiler/anyIndexedAccessArrayNoException.ts (2 errors) ====
+==== tests/cases/compiler/anyIndexedAccessArrayNoException.ts (1 errors) ====
     var x: any[[]];
                ~~
-!!! error TS1122: A tuple type element list cannot be empty.
-               ~~
 !!! error TS2538: Type '[]' cannot be used as an index type.
     
\ No newline at end of file
diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
index bf6db412bf8..837497afc84 100644
--- a/tests/baselines/reference/api/tsserverlibrary.d.ts
+++ b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -231,143 +231,144 @@ declare namespace ts {
         TypeLiteral = 166,
         ArrayType = 167,
         TupleType = 168,
-        UnionType = 169,
-        IntersectionType = 170,
-        ConditionalType = 171,
-        InferType = 172,
-        ParenthesizedType = 173,
-        ThisType = 174,
-        TypeOperator = 175,
-        IndexedAccessType = 176,
-        MappedType = 177,
-        LiteralType = 178,
-        ImportType = 179,
-        ObjectBindingPattern = 180,
-        ArrayBindingPattern = 181,
-        BindingElement = 182,
-        ArrayLiteralExpression = 183,
-        ObjectLiteralExpression = 184,
-        PropertyAccessExpression = 185,
-        ElementAccessExpression = 186,
-        CallExpression = 187,
-        NewExpression = 188,
-        TaggedTemplateExpression = 189,
-        TypeAssertionExpression = 190,
-        ParenthesizedExpression = 191,
-        FunctionExpression = 192,
-        ArrowFunction = 193,
-        DeleteExpression = 194,
-        TypeOfExpression = 195,
-        VoidExpression = 196,
-        AwaitExpression = 197,
-        PrefixUnaryExpression = 198,
-        PostfixUnaryExpression = 199,
-        BinaryExpression = 200,
-        ConditionalExpression = 201,
-        TemplateExpression = 202,
-        YieldExpression = 203,
-        SpreadElement = 204,
-        ClassExpression = 205,
-        OmittedExpression = 206,
-        ExpressionWithTypeArguments = 207,
-        AsExpression = 208,
-        NonNullExpression = 209,
-        MetaProperty = 210,
-        TemplateSpan = 211,
-        SemicolonClassElement = 212,
-        Block = 213,
-        VariableStatement = 214,
-        EmptyStatement = 215,
-        ExpressionStatement = 216,
-        IfStatement = 217,
-        DoStatement = 218,
-        WhileStatement = 219,
-        ForStatement = 220,
-        ForInStatement = 221,
-        ForOfStatement = 222,
-        ContinueStatement = 223,
-        BreakStatement = 224,
-        ReturnStatement = 225,
-        WithStatement = 226,
-        SwitchStatement = 227,
-        LabeledStatement = 228,
-        ThrowStatement = 229,
-        TryStatement = 230,
-        DebuggerStatement = 231,
-        VariableDeclaration = 232,
-        VariableDeclarationList = 233,
-        FunctionDeclaration = 234,
-        ClassDeclaration = 235,
-        InterfaceDeclaration = 236,
-        TypeAliasDeclaration = 237,
-        EnumDeclaration = 238,
-        ModuleDeclaration = 239,
-        ModuleBlock = 240,
-        CaseBlock = 241,
-        NamespaceExportDeclaration = 242,
-        ImportEqualsDeclaration = 243,
-        ImportDeclaration = 244,
-        ImportClause = 245,
-        NamespaceImport = 246,
-        NamedImports = 247,
-        ImportSpecifier = 248,
-        ExportAssignment = 249,
-        ExportDeclaration = 250,
-        NamedExports = 251,
-        ExportSpecifier = 252,
-        MissingDeclaration = 253,
-        ExternalModuleReference = 254,
-        JsxElement = 255,
-        JsxSelfClosingElement = 256,
-        JsxOpeningElement = 257,
-        JsxClosingElement = 258,
-        JsxFragment = 259,
-        JsxOpeningFragment = 260,
-        JsxClosingFragment = 261,
-        JsxAttribute = 262,
-        JsxAttributes = 263,
-        JsxSpreadAttribute = 264,
-        JsxExpression = 265,
-        CaseClause = 266,
-        DefaultClause = 267,
-        HeritageClause = 268,
-        CatchClause = 269,
-        PropertyAssignment = 270,
-        ShorthandPropertyAssignment = 271,
-        SpreadAssignment = 272,
-        EnumMember = 273,
-        SourceFile = 274,
-        Bundle = 275,
-        UnparsedSource = 276,
-        InputFiles = 277,
-        JSDocTypeExpression = 278,
-        JSDocAllType = 279,
-        JSDocUnknownType = 280,
-        JSDocNullableType = 281,
-        JSDocNonNullableType = 282,
-        JSDocOptionalType = 283,
-        JSDocFunctionType = 284,
-        JSDocVariadicType = 285,
-        JSDocComment = 286,
-        JSDocTypeLiteral = 287,
-        JSDocSignature = 288,
-        JSDocTag = 289,
-        JSDocAugmentsTag = 290,
-        JSDocClassTag = 291,
-        JSDocCallbackTag = 292,
-        JSDocParameterTag = 293,
-        JSDocReturnTag = 294,
-        JSDocTypeTag = 295,
-        JSDocTemplateTag = 296,
-        JSDocTypedefTag = 297,
-        JSDocPropertyTag = 298,
-        SyntaxList = 299,
-        NotEmittedStatement = 300,
-        PartiallyEmittedExpression = 301,
-        CommaListExpression = 302,
-        MergeDeclarationMarker = 303,
-        EndOfDeclarationMarker = 304,
-        Count = 305,
+        OptionalType = 169,
+        UnionType = 170,
+        IntersectionType = 171,
+        ConditionalType = 172,
+        InferType = 173,
+        ParenthesizedType = 174,
+        ThisType = 175,
+        TypeOperator = 176,
+        IndexedAccessType = 177,
+        MappedType = 178,
+        LiteralType = 179,
+        ImportType = 180,
+        ObjectBindingPattern = 181,
+        ArrayBindingPattern = 182,
+        BindingElement = 183,
+        ArrayLiteralExpression = 184,
+        ObjectLiteralExpression = 185,
+        PropertyAccessExpression = 186,
+        ElementAccessExpression = 187,
+        CallExpression = 188,
+        NewExpression = 189,
+        TaggedTemplateExpression = 190,
+        TypeAssertionExpression = 191,
+        ParenthesizedExpression = 192,
+        FunctionExpression = 193,
+        ArrowFunction = 194,
+        DeleteExpression = 195,
+        TypeOfExpression = 196,
+        VoidExpression = 197,
+        AwaitExpression = 198,
+        PrefixUnaryExpression = 199,
+        PostfixUnaryExpression = 200,
+        BinaryExpression = 201,
+        ConditionalExpression = 202,
+        TemplateExpression = 203,
+        YieldExpression = 204,
+        SpreadElement = 205,
+        ClassExpression = 206,
+        OmittedExpression = 207,
+        ExpressionWithTypeArguments = 208,
+        AsExpression = 209,
+        NonNullExpression = 210,
+        MetaProperty = 211,
+        TemplateSpan = 212,
+        SemicolonClassElement = 213,
+        Block = 214,
+        VariableStatement = 215,
+        EmptyStatement = 216,
+        ExpressionStatement = 217,
+        IfStatement = 218,
+        DoStatement = 219,
+        WhileStatement = 220,
+        ForStatement = 221,
+        ForInStatement = 222,
+        ForOfStatement = 223,
+        ContinueStatement = 224,
+        BreakStatement = 225,
+        ReturnStatement = 226,
+        WithStatement = 227,
+        SwitchStatement = 228,
+        LabeledStatement = 229,
+        ThrowStatement = 230,
+        TryStatement = 231,
+        DebuggerStatement = 232,
+        VariableDeclaration = 233,
+        VariableDeclarationList = 234,
+        FunctionDeclaration = 235,
+        ClassDeclaration = 236,
+        InterfaceDeclaration = 237,
+        TypeAliasDeclaration = 238,
+        EnumDeclaration = 239,
+        ModuleDeclaration = 240,
+        ModuleBlock = 241,
+        CaseBlock = 242,
+        NamespaceExportDeclaration = 243,
+        ImportEqualsDeclaration = 244,
+        ImportDeclaration = 245,
+        ImportClause = 246,
+        NamespaceImport = 247,
+        NamedImports = 248,
+        ImportSpecifier = 249,
+        ExportAssignment = 250,
+        ExportDeclaration = 251,
+        NamedExports = 252,
+        ExportSpecifier = 253,
+        MissingDeclaration = 254,
+        ExternalModuleReference = 255,
+        JsxElement = 256,
+        JsxSelfClosingElement = 257,
+        JsxOpeningElement = 258,
+        JsxClosingElement = 259,
+        JsxFragment = 260,
+        JsxOpeningFragment = 261,
+        JsxClosingFragment = 262,
+        JsxAttribute = 263,
+        JsxAttributes = 264,
+        JsxSpreadAttribute = 265,
+        JsxExpression = 266,
+        CaseClause = 267,
+        DefaultClause = 268,
+        HeritageClause = 269,
+        CatchClause = 270,
+        PropertyAssignment = 271,
+        ShorthandPropertyAssignment = 272,
+        SpreadAssignment = 273,
+        EnumMember = 274,
+        SourceFile = 275,
+        Bundle = 276,
+        UnparsedSource = 277,
+        InputFiles = 278,
+        JSDocTypeExpression = 279,
+        JSDocAllType = 280,
+        JSDocUnknownType = 281,
+        JSDocNullableType = 282,
+        JSDocNonNullableType = 283,
+        JSDocOptionalType = 284,
+        JSDocFunctionType = 285,
+        JSDocVariadicType = 286,
+        JSDocComment = 287,
+        JSDocTypeLiteral = 288,
+        JSDocSignature = 289,
+        JSDocTag = 290,
+        JSDocAugmentsTag = 291,
+        JSDocClassTag = 292,
+        JSDocCallbackTag = 293,
+        JSDocParameterTag = 294,
+        JSDocReturnTag = 295,
+        JSDocTypeTag = 296,
+        JSDocTemplateTag = 297,
+        JSDocTypedefTag = 298,
+        JSDocPropertyTag = 299,
+        SyntaxList = 300,
+        NotEmittedStatement = 301,
+        PartiallyEmittedExpression = 302,
+        CommaListExpression = 303,
+        MergeDeclarationMarker = 304,
+        EndOfDeclarationMarker = 305,
+        Count = 306,
         FirstAssignment = 58,
         LastAssignment = 70,
         FirstCompoundAssignment = 59,
@@ -379,7 +380,7 @@ declare namespace ts {
         FirstFutureReservedWord = 108,
         LastFutureReservedWord = 116,
         FirstTypeNode = 161,
-        LastTypeNode = 179,
+        LastTypeNode = 180,
         FirstPunctuation = 17,
         LastPunctuation = 70,
         FirstToken = 0,
@@ -393,10 +394,10 @@ declare namespace ts {
         FirstBinaryOperator = 27,
         LastBinaryOperator = 70,
         FirstNode = 146,
-        FirstJSDocNode = 278,
-        LastJSDocNode = 298,
-        FirstJSDocTagNode = 289,
-        LastJSDocTagNode = 298
+        FirstJSDocNode = 279,
+        LastJSDocNode = 299,
+        FirstJSDocTagNode = 290,
+        LastJSDocTagNode = 299
     }
     enum NodeFlags {
         None = 0,
@@ -751,6 +752,10 @@ declare namespace ts {
         kind: SyntaxKind.TupleType;
         elementTypes: NodeArray<TypeNode>;
     }
+    interface OptionalTypeNode extends TypeNode {
+        kind: SyntaxKind.OptionalType;
+        type: TypeNode;
+    }
     type UnionOrIntersectionTypeNode = UnionTypeNode | IntersectionTypeNode;
     interface UnionTypeNode extends TypeNode {
         kind: SyntaxKind.UnionType;
@@ -2249,6 +2254,9 @@ declare namespace ts {
     }
     interface GenericType extends InterfaceType, TypeReference {
     }
+    interface TupleType extends GenericType {
+        minLength: number;
+    }
     interface UnionOrIntersectionType extends Type {
         types: Type[];
     }
@@ -3590,7 +3598,9 @@ declare namespace ts {
     function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
     function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
     function createTupleTypeNode(elementTypes: ReadonlyArray<TypeNode>): TupleTypeNode;
-    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: ReadonlyArray<TypeNode>): TupleTypeNode;
+    function updateTupleTypeNode(node: TupleTypeNode, elementTypes: ReadonlyArray<TypeNode>): TupleTypeNode;
+    function createOptionalTypeNode(type: TypeNode): OptionalTypeNode;
+    function updateOptionalTypeNode(node: OptionalTypeNode, type: TypeNode): OptionalTypeNode;
     function createUnionTypeNode(types: ReadonlyArray<TypeNode>): UnionTypeNode;
     function updateUnionTypeNode(node: UnionTypeNode, types: NodeArray<TypeNode>): UnionTypeNode;
     function createIntersectionTypeNode(types: ReadonlyArray<TypeNode>): IntersectionTypeNode;
diff --git a/tests/baselines/reference/api/typescript.d.ts b/tests/baselines/reference/api/typescript.d.ts
index 32316e23f12..8a3315927a3 100644
--- a/tests/baselines/reference/api/typescript.d.ts
+++ b/tests/baselines/reference/api/typescript.d.ts
@@ -231,143 +231,144 @@ declare namespace ts {
         TypeLiteral = 166,
         ArrayType = 167,
         TupleType = 168,
-        UnionType = 169,
-        IntersectionType = 170,
-        ConditionalType = 171,
-        InferType = 172,
-        ParenthesizedType = 173,
-        ThisType = 174,
-        TypeOperator = 175,
-        IndexedAccessType = 176,
-        MappedType = 177,
-        LiteralType = 178,
-        ImportType = 179,
-        ObjectBindingPattern = 180,
-        ArrayBindingPattern = 181,
-        BindingElement = 182,
-        ArrayLiteralExpression = 183,
-        ObjectLiteralExpression = 184,
-        PropertyAccessExpression = 185,
-        ElementAccessExpression = 186,
-        CallExpression = 187,
-        NewExpression = 188,
-        TaggedTemplateExpression = 189,
-        TypeAssertionExpression = 190,
-        ParenthesizedExpression = 191,
-        FunctionExpression = 192,
-        ArrowFunction = 193,
-        DeleteExpression = 194,
-        TypeOfExpression = 195,
-        VoidExpression = 196,
-        AwaitExpression = 197,
-        PrefixUnaryExpression = 198,
-        PostfixUnaryExpression = 199,
-        BinaryExpression = 200,
-        ConditionalExpression = 201,
-        TemplateExpression = 202,
-        YieldExpression = 203,
-        SpreadElement = 204,
-        ClassExpression = 205,
-        OmittedExpression = 206,
-        ExpressionWithTypeArguments = 207,
-        AsExpression = 208,
-        NonNullExpression = 209,
-        MetaProperty = 210,
-        TemplateSpan = 211,
-        SemicolonClassElement = 212,
-        Block = 213,
-        VariableStatement = 214,
-        EmptyStatement = 215,
-        ExpressionStatement = 216,
-        IfStatement = 217,
-        DoStatement = 218,
-        WhileStatement = 219,
-        ForStatement = 220,
-        ForInStatement = 221,
-        ForOfStatement = 222,
-        ContinueStatement = 223,
-        BreakStatement = 224,
-        ReturnStatement = 225,
-        WithStatement = 226,
-        SwitchStatement = 227,
-        LabeledStatement = 228,
-        ThrowStatement = 229,
-        TryStatement = 230,
-        DebuggerStatement = 231,
-        VariableDeclaration = 232,
-        VariableDeclarationList = 233,
-        FunctionDeclaration = 234,
-        ClassDeclaration = 235,
-        InterfaceDeclaration = 236,
-        TypeAliasDeclaration = 237,
-        EnumDeclaration = 238,
-        ModuleDeclaration = 239,
-        ModuleBlock = 240,
-        CaseBlock = 241,
-        NamespaceExportDeclaration = 242,
-        ImportEqualsDeclaration = 243,
-        ImportDeclaration = 244,
-        ImportClause = 245,
-        NamespaceImport = 246,
-        NamedImports = 247,
-        ImportSpecifier = 248,
-        ExportAssignment = 249,
-        ExportDeclaration = 250,
-        NamedExports = 251,
-        ExportSpecifier = 252,
-        MissingDeclaration = 253,
-        ExternalModuleReference = 254,
-        JsxElement = 255,
-        JsxSelfClosingElement = 256,
-        JsxOpeningElement = 257,
-        JsxClosingElement = 258,
-        JsxFragment = 259,
-        JsxOpeningFragment = 260,
-        JsxClosingFragment = 261,
-        JsxAttribute = 262,
-        JsxAttributes = 263,
-        JsxSpreadAttribute = 264,
-        JsxExpression = 265,
-        CaseClause = 266,
-        DefaultClause = 267,
-        HeritageClause = 268,
-        CatchClause = 269,
-        PropertyAssignment = 270,
-        ShorthandPropertyAssignment = 271,
-        SpreadAssignment = 272,
-        EnumMember = 273,
-        SourceFile = 274,
-        Bundle = 275,
-        UnparsedSource = 276,
-        InputFiles = 277,
-        JSDocTypeExpression = 278,
-        JSDocAllType = 279,
-        JSDocUnknownType = 280,
-        JSDocNullableType = 281,
-        JSDocNonNullableType = 282,
-        JSDocOptionalType = 283,
-        JSDocFunctionType = 284,
-        JSDocVariadicType = 285,
-        JSDocComment = 286,
-        JSDocTypeLiteral = 287,
-        JSDocSignature = 288,
-        JSDocTag = 289,
-        JSDocAugmentsTag = 290,
-        JSDocClassTag = 291,
-        JSDocCallbackTag = 292,
-        JSDocParameterTag = 293,
-        JSDocReturnTag = 294,
-        JSDocTypeTag = 295,
-        JSDocTemplateTag = 296,
-        JSDocTypedefTag = 297,
-        JSDocPropertyTag = 298,
-        SyntaxList = 299,
-        NotEmittedStatement = 300,
-        PartiallyEmittedExpression = 301,
-        CommaListExpression = 302,
-        MergeDeclarationMarker = 303,
-        EndOfDeclarationMarker = 304,
-        Count = 305,
+        OptionalType = 169,
+        UnionType = 170,
+        IntersectionType = 171,
+        ConditionalType = 172,
+        InferType = 173,
+        ParenthesizedType = 174,
+        ThisType = 175,
+        TypeOperator = 176,
+        IndexedAccessType = 177,
+        MappedType = 178,
+        LiteralType = 179,
+        ImportType = 180,
+        ObjectBindingPattern = 181,
+        ArrayBindingPattern = 182,
+        BindingElement = 183,
+        ArrayLiteralExpression = 184,
+        ObjectLiteralExpression = 185,
+        PropertyAccessExpression = 186,
+        ElementAccessExpression = 187,
+        CallExpression = 188,
+        NewExpression = 189,
+        TaggedTemplateExpression = 190,
+        TypeAssertionExpression = 191,
+        ParenthesizedExpression = 192,
+        FunctionExpression = 193,
+        ArrowFunction = 194,
+        DeleteExpression = 195,
+        TypeOfExpression = 196,
+        VoidExpression = 197,
+        AwaitExpression = 198,
+        PrefixUnaryExpression = 199,
+        PostfixUnaryExpression = 200,
+        BinaryExpression = 201,
+        ConditionalExpression = 202,
+        TemplateExpression = 203,
+        YieldExpression = 204,
+        SpreadElement = 205,
+        ClassExpression = 206,
+        OmittedExpression = 207,
+        ExpressionWithTypeArguments = 208,
+        AsExpression = 209,
+        NonNullExpression = 210,
+        MetaProperty = 211,
+        TemplateSpan = 212,
+        SemicolonClassElement = 213,
+        Block = 214,
+        VariableStatement = 215,
+        EmptyStatement = 216,
+        ExpressionStatement = 217,
+        IfStatement = 218,
+        DoStatement = 219,
+        WhileStatement = 220,
+        ForStatement = 221,
+        ForInStatement = 222,
+        ForOfStatement = 223,
+        ContinueStatement = 224,
+        BreakStatement = 225,
+        ReturnStatement = 226,
+        WithStatement = 227,
+        SwitchStatement = 228,
+        LabeledStatement = 229,
+        ThrowStatement = 230,
+        TryStatement = 231,
+        DebuggerStatement = 232,
+        VariableDeclaration = 233,
+        VariableDeclarationList = 234,
+        FunctionDeclaration = 235,
+        ClassDeclaration = 236,
+        InterfaceDeclaration = 237,
+        TypeAliasDeclaration = 238,
+        EnumDeclaration = 239,
+        ModuleDeclaration = 240,
+        ModuleBlock = 241,
+        CaseBlock = 242,
+        NamespaceExportDeclaration = 243,
+        ImportEqualsDeclaration = 244,
+        ImportDeclaration = 245,
+        ImportClause = 246,
+        NamespaceImport = 247,
+        NamedImports = 248,
+        ImportSpecifier = 249,
+        ExportAssignment = 250,
+        ExportDeclaration = 251,
+        NamedExports = 252,
+        ExportSpecifier = 253,
+        MissingDeclaration = 254,
+        ExternalModuleReference = 255,
+        JsxElement = 256,
+        JsxSelfClosingElement = 257,
+        JsxOpeningElement = 258,
+        JsxClosingElement = 259,
+        JsxFragment = 260,
+        JsxOpeningFragment = 261,
+        JsxClosingFragment = 262,
+        JsxAttribute = 263,
+        JsxAttributes = 264,
+        JsxSpreadAttribute = 265,
+        JsxExpression = 266,
+        CaseClause = 267,
+        DefaultClause = 268,
+        HeritageClause = 269,
+        CatchClause = 270,
+        PropertyAssignment = 271,
+        ShorthandPropertyAssignment = 272,
+        SpreadAssignment = 273,
+        EnumMember = 274,
+        SourceFile = 275,
+        Bundle = 276,
+        UnparsedSource = 277,
+        InputFiles = 278,
+        JSDocTypeExpression = 279,
+        JSDocAllType = 280,
+        JSDocUnknownType = 281,
+        JSDocNullableType = 282,
+        JSDocNonNullableType = 283,
+        JSDocOptionalType = 284,
+        JSDocFunctionType = 285,
+        JSDocVariadicType = 286,
+        JSDocComment = 287,
+        JSDocTypeLiteral = 288,
+        JSDocSignature = 289,
+        JSDocTag = 290,
+        JSDocAugmentsTag = 291,
+        JSDocClassTag = 292,
+        JSDocCallbackTag = 293,
+        JSDocParameterTag = 294,
+        JSDocReturnTag = 295,
+        JSDocTypeTag = 296,
+        JSDocTemplateTag = 297,
+        JSDocTypedefTag = 298,
+        JSDocPropertyTag = 299,
+        SyntaxList = 300,
+        NotEmittedStatement = 301,
+        PartiallyEmittedExpression = 302,
+        CommaListExpression = 303,
+        MergeDeclarationMarker = 304,
+        EndOfDeclarationMarker = 305,
+        Count = 306,
         FirstAssignment = 58,
         LastAssignment = 70,
         FirstCompoundAssignment = 59,
@@ -379,7 +380,7 @@ declare namespace ts {
         FirstFutureReservedWord = 108,
         LastFutureReservedWord = 116,
         FirstTypeNode = 161,
-        LastTypeNode = 179,
+        LastTypeNode = 180,
         FirstPunctuation = 17,
         LastPunctuation = 70,
         FirstToken = 0,
@@ -393,10 +394,10 @@ declare namespace ts {
         FirstBinaryOperator = 27,
         LastBinaryOperator = 70,
         FirstNode = 146,
-        FirstJSDocNode = 278,
-        LastJSDocNode = 298,
-        FirstJSDocTagNode = 289,
-        LastJSDocTagNode = 298
+        FirstJSDocNode = 279,
+        LastJSDocNode = 299,
+        FirstJSDocTagNode = 290,
+        LastJSDocTagNode = 299
     }
     enum NodeFlags {
         None = 0,
@@ -751,6 +752,10 @@ declare namespace ts {
         kind: SyntaxKind.TupleType;
         elementTypes: NodeArray<TypeNode>;
     }
+    interface OptionalTypeNode extends TypeNode {
+        kind: SyntaxKind.OptionalType;
+        type: TypeNode;
+    }
     type UnionOrIntersectionTypeNode = UnionTypeNode | IntersectionTypeNode;
     interface UnionTypeNode extends TypeNode {
         kind: SyntaxKind.UnionType;
@@ -2249,6 +2254,9 @@ declare namespace ts {
     }
     interface GenericType extends InterfaceType, TypeReference {
     }
+    interface TupleType extends GenericType {
+        minLength: number;
+    }
     interface UnionOrIntersectionType extends Type {
         types: Type[];
     }
@@ -3590,7 +3598,9 @@ declare namespace ts {
     function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
     function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
     function createTupleTypeNode(elementTypes: ReadonlyArray<TypeNode>): TupleTypeNode;
-    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: ReadonlyArray<TypeNode>): TupleTypeNode;
+    function updateTupleTypeNode(node: TupleTypeNode, elementTypes: ReadonlyArray<TypeNode>): TupleTypeNode;
+    function createOptionalTypeNode(type: TypeNode): OptionalTypeNode;
+    function updateOptionalTypeNode(node: OptionalTypeNode, type: TypeNode): OptionalTypeNode;
     function createUnionTypeNode(types: ReadonlyArray<TypeNode>): UnionTypeNode;
     function updateUnionTypeNode(node: UnionTypeNode, types: NodeArray<TypeNode>): UnionTypeNode;
     function createIntersectionTypeNode(types: ReadonlyArray<TypeNode>): IntersectionTypeNode;
diff --git a/tests/baselines/reference/arrayLiterals3.errors.txt b/tests/baselines/reference/arrayLiterals3.errors.txt
index a3a3b88bc4a..8ce34900b0a 100644
--- a/tests/baselines/reference/arrayLiterals3.errors.txt
+++ b/tests/baselines/reference/arrayLiterals3.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(10,5): error TS2322: Type 'undefined[]' is not assignable to type '[any, any, any]'.
-  Property '0' is missing in type 'undefined[]'.
+tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(10,5): error TS2322: Type '[]' is not assignable to type '[any, any, any]'.
+  Property '0' is missing in type '[]'.
 tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(11,5): error TS2322: Type '[string, number, boolean]' is not assignable to type '[boolean, string, number]'.
   Type 'string' is not assignable to type 'boolean'.
 tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(17,5): error TS2322: Type '[number, number, string, boolean]' is not assignable to type '[number, number]'.
@@ -30,8 +30,8 @@ tests/cases/conformance/expressions/arrayLiterals/arrayLiterals3.ts(34,5): error
     
     var a0: [any, any, any] = [];                             // Error
         ~~
-!!! error TS2322: Type 'undefined[]' is not assignable to type '[any, any, any]'.
-!!! error TS2322:   Property '0' is missing in type 'undefined[]'.
+!!! error TS2322: Type '[]' is not assignable to type '[any, any, any]'.
+!!! error TS2322:   Property '0' is missing in type '[]'.
     var a1: [boolean, string, number] = ["string", 1, true];  // Error
         ~~
 !!! error TS2322: Type '[string, number, boolean]' is not assignable to type '[boolean, string, number]'.
diff --git a/tests/baselines/reference/arrayLiterals3.types b/tests/baselines/reference/arrayLiterals3.types
index 7d890f38fb4..bf3ff4cf4f6 100644
--- a/tests/baselines/reference/arrayLiterals3.types
+++ b/tests/baselines/reference/arrayLiterals3.types
@@ -10,7 +10,7 @@
 
 var a0: [any, any, any] = [];                             // Error
 >a0 : [any, any, any]
->[] : undefined[]
+>[] : []
 
 var a1: [boolean, string, number] = ["string", 1, true];  // Error
 >a1 : [boolean, string, number]
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion01.errors.txt b/tests/baselines/reference/emptyTuplesTypeAssertion01.errors.txt
deleted file mode 100644
index bfe850a5749..00000000000
--- a/tests/baselines/reference/emptyTuplesTypeAssertion01.errors.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion01.ts(1,10): error TS1122: A tuple type element list cannot be empty.
-
-
-==== tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion01.ts (1 errors) ====
-    let x = <[]>[];
-             ~~
-!!! error TS1122: A tuple type element list cannot be empty.
-    let y = x[0];
\ No newline at end of file
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion01.types b/tests/baselines/reference/emptyTuplesTypeAssertion01.types
index 3ccfab4cb61..0a278c01d31 100644
--- a/tests/baselines/reference/emptyTuplesTypeAssertion01.types
+++ b/tests/baselines/reference/emptyTuplesTypeAssertion01.types
@@ -2,7 +2,7 @@
 let x = <[]>[];
 >x : []
 ><[]>[] : []
->[] : undefined[]
+>[] : []
 
 let y = x[0];
 >y : never
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion02.errors.txt b/tests/baselines/reference/emptyTuplesTypeAssertion02.errors.txt
deleted file mode 100644
index 1bbf96e6aec..00000000000
--- a/tests/baselines/reference/emptyTuplesTypeAssertion02.errors.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion02.ts(1,15): error TS1122: A tuple type element list cannot be empty.
-
-
-==== tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion02.ts (1 errors) ====
-    let x = [] as [];
-                  ~~
-!!! error TS1122: A tuple type element list cannot be empty.
-    let y = x[0];
\ No newline at end of file
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion02.types b/tests/baselines/reference/emptyTuplesTypeAssertion02.types
index 9b791a5e415..ef35e90eac2 100644
--- a/tests/baselines/reference/emptyTuplesTypeAssertion02.types
+++ b/tests/baselines/reference/emptyTuplesTypeAssertion02.types
@@ -2,7 +2,7 @@
 let x = [] as [];
 >x : []
 >[] as [] : []
->[] : undefined[]
+>[] : []
 
 let y = x[0];
 >y : never
diff --git a/tests/baselines/reference/keyofAndIndexedAccessErrors.errors.txt b/tests/baselines/reference/keyofAndIndexedAccessErrors.errors.txt
index c74c90c510f..14cfbd1ceab 100644
--- a/tests/baselines/reference/keyofAndIndexedAccessErrors.errors.txt
+++ b/tests/baselines/reference/keyofAndIndexedAccessErrors.errors.txt
@@ -15,7 +15,6 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(35,21): error
 tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(36,21): error TS2538: Type 'boolean' cannot be used as an index type.
 tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(41,31): error TS2538: Type 'boolean' cannot be used as an index type.
 tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(46,16): error TS2538: Type 'boolean' cannot be used as an index type.
-tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(49,12): error TS1122: A tuple type element list cannot be empty.
 tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(63,33): error TS2345: Argument of type '"size"' is not assignable to parameter of type '"name" | "width" | "height" | "visible"'.
 tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(64,33): error TS2345: Argument of type '"name" | "size"' is not assignable to parameter of type '"name" | "width" | "height" | "visible"'.
   Type '"size"' is not assignable to type '"name" | "width" | "height" | "visible"'.
@@ -61,7 +60,7 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(117,5): error
   Type 'T' is not assignable to type 'U'.
 
 
-==== tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts (34 errors) ====
+==== tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts (33 errors) ====
     class Shape {
         name: string;
         width: number;
@@ -145,8 +144,6 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(117,5): error
     
     type T60 = {}["toString"];
     type T61 = []["toString"];
-               ~~
-!!! error TS1122: A tuple type element list cannot be empty.
     
     declare let cond: boolean;
     
diff --git a/tests/baselines/reference/promiseEmptyTupleNoException.errors.txt b/tests/baselines/reference/promiseEmptyTupleNoException.errors.txt
index 73d768ddfeb..77e78a676b4 100644
--- a/tests/baselines/reference/promiseEmptyTupleNoException.errors.txt
+++ b/tests/baselines/reference/promiseEmptyTupleNoException.errors.txt
@@ -1,13 +1,10 @@
-tests/cases/compiler/promiseEmptyTupleNoException.ts(1,38): error TS1122: A tuple type element list cannot be empty.
 tests/cases/compiler/promiseEmptyTupleNoException.ts(3,3): error TS2322: Type 'any[]' is not assignable to type '[]'.
   Types of property 'length' are incompatible.
     Type 'number' is not assignable to type '0'.
 
 
-==== tests/cases/compiler/promiseEmptyTupleNoException.ts (2 errors) ====
+==== tests/cases/compiler/promiseEmptyTupleNoException.ts (1 errors) ====
     export async function get(): Promise<[]> {
-                                         ~~
-!!! error TS1122: A tuple type element list cannot be empty.
       let emails = [];
       return emails;
       ~~~~~~~~~~~~~~
diff --git a/tests/baselines/reference/strictTupleLength.errors.txt b/tests/baselines/reference/strictTupleLength.errors.txt
index 23915f1f6fa..a4a51cc9b0f 100644
--- a/tests/baselines/reference/strictTupleLength.errors.txt
+++ b/tests/baselines/reference/strictTupleLength.errors.txt
@@ -1,14 +1,11 @@
-tests/cases/conformance/types/tuple/strictTupleLength.ts(1,9): error TS1122: A tuple type element list cannot be empty.
 tests/cases/conformance/types/tuple/strictTupleLength.ts(11,5): error TS2403: Subsequent variable declarations must have the same type.  Variable 't1' must be of type '[number]', but here has type '[number, number]'.
 tests/cases/conformance/types/tuple/strictTupleLength.ts(12,5): error TS2403: Subsequent variable declarations must have the same type.  Variable 't2' must be of type '[number, number]', but here has type '[number]'.
 tests/cases/conformance/types/tuple/strictTupleLength.ts(18,1): error TS2322: Type 'number[]' is not assignable to type '[number]'.
   Property '0' is missing in type 'number[]'.
 
 
-==== tests/cases/conformance/types/tuple/strictTupleLength.ts (4 errors) ====
+==== tests/cases/conformance/types/tuple/strictTupleLength.ts (3 errors) ====
     var t0: [];
-            ~~
-!!! error TS1122: A tuple type element list cannot be empty.
     var t1: [number];
     var t2: [number, number];
     var arr: number[];
diff --git a/tests/baselines/reference/tupleTypes.errors.txt b/tests/baselines/reference/tupleTypes.errors.txt
index 16a8f66ba79..e2b73b7613a 100644
--- a/tests/baselines/reference/tupleTypes.errors.txt
+++ b/tests/baselines/reference/tupleTypes.errors.txt
@@ -1,6 +1,5 @@
-tests/cases/compiler/tupleTypes.ts(1,9): error TS1122: A tuple type element list cannot be empty.
-tests/cases/compiler/tupleTypes.ts(14,1): error TS2322: Type 'undefined[]' is not assignable to type '[number, string]'.
-  Property '0' is missing in type 'undefined[]'.
+tests/cases/compiler/tupleTypes.ts(14,1): error TS2322: Type '[]' is not assignable to type '[number, string]'.
+  Property '0' is missing in type '[]'.
 tests/cases/compiler/tupleTypes.ts(15,1): error TS2322: Type '[number]' is not assignable to type '[number, string]'.
   Property '1' is missing in type '[number]'.
 tests/cases/compiler/tupleTypes.ts(17,1): error TS2322: Type '[string, number]' is not assignable to type '[number, string]'.
@@ -8,7 +7,7 @@ tests/cases/compiler/tupleTypes.ts(17,1): error TS2322: Type '[string, number]'
 tests/cases/compiler/tupleTypes.ts(18,1): error TS2322: Type '[number, string, number]' is not assignable to type '[number, string]'.
   Types of property 'length' are incompatible.
     Type '3' is not assignable to type '2'.
-tests/cases/compiler/tupleTypes.ts(41,1): error TS2322: Type 'undefined[]' is not assignable to type '[number, string]'.
+tests/cases/compiler/tupleTypes.ts(41,1): error TS2322: Type '[]' is not assignable to type '[number, string]'.
 tests/cases/compiler/tupleTypes.ts(47,1): error TS2322: Type '[number, string]' is not assignable to type 'number[]'.
   Types of property 'pop' are incompatible.
     Type '() => string | number' is not assignable to type '() => number'.
@@ -25,10 +24,8 @@ tests/cases/compiler/tupleTypes.ts(51,1): error TS2322: Type '[number, {}]' is n
   Type '{}' is not assignable to type 'string'.
 
 
-==== tests/cases/compiler/tupleTypes.ts (10 errors) ====
+==== tests/cases/compiler/tupleTypes.ts (9 errors) ====
     var v1: [];  // Error
-            ~~
-!!! error TS1122: A tuple type element list cannot be empty.
     var v2: [number];
     var v3: [number, string];
     var v4: [number, [string, string]];
@@ -43,8 +40,8 @@ tests/cases/compiler/tupleTypes.ts(51,1): error TS2322: Type '[number, {}]' is n
     
     t = [];               // Error
     ~
-!!! error TS2322: Type 'undefined[]' is not assignable to type '[number, string]'.
-!!! error TS2322:   Property '0' is missing in type 'undefined[]'.
+!!! error TS2322: Type '[]' is not assignable to type '[number, string]'.
+!!! error TS2322:   Property '0' is missing in type '[]'.
     t = [1];              // Error
     ~
 !!! error TS2322: Type '[number]' is not assignable to type '[number, string]'.
@@ -83,7 +80,7 @@ tests/cases/compiler/tupleTypes.ts(51,1): error TS2322: Type '[number, {}]' is n
     tt = [undefined, undefined];
     tt = [];  // Error
     ~~
-!!! error TS2322: Type 'undefined[]' is not assignable to type '[number, string]'.
+!!! error TS2322: Type '[]' is not assignable to type '[number, string]'.
     
     var a: number[];
     var a1: [number, string];
diff --git a/tests/baselines/reference/tupleTypes.types b/tests/baselines/reference/tupleTypes.types
index 3f68d4c7e2d..2bedb114312 100644
--- a/tests/baselines/reference/tupleTypes.types
+++ b/tests/baselines/reference/tupleTypes.types
@@ -42,9 +42,9 @@ var t2: number|string;
 >t2 : string | number
 
 t = [];               // Error
->t = [] : undefined[]
+>t = [] : []
 >t : [number, string]
->[] : undefined[]
+>[] : []
 
 t = [1];              // Error
 >t = [1] : [number]
@@ -188,9 +188,9 @@ tt = [undefined, undefined];
 >undefined : undefined
 
 tt = [];  // Error
->tt = [] : undefined[]
+>tt = [] : []
 >tt : [number, string]
->[] : undefined[]
+>[] : []
 
 var a: number[];
 >a : number[]