ditch empty tuple check

KiaraGrouwstra · KiaraGrouwstra · commit 665f44fdd1ef · 2017-08-13T16:38:48.000+08:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -2646,11 +2646,7 @@ namespace ts {
                                 return createTupleTypeNode(tupleConstituentNodes);
                             }
                         }
-                        if (context.encounteredError || (context.flags & NodeBuilderFlags.AllowEmptyTuple)) {
-                            return createTupleTypeNode([]);
-                        }
-                        context.encounteredError = true;
-                        return undefined;
+                        return createTupleTypeNode([]);
                     }
                     else {
                         const outerTypeParameters = type.target.outerTypeParameters;
@@ -18737,10 +18733,6 @@ namespace ts {
         function checkTupleType(node: TupleTypeNode) {
             // Grammar checking
             const hasErrorFromDisallowedTrailingComma = checkGrammarForDisallowedTrailingComma(node.elementTypes);
-            if (!hasErrorFromDisallowedTrailingComma && node.elementTypes.length === 0) {
-                grammarErrorOnNode(node, Diagnostics.A_tuple_type_element_list_cannot_be_empty);
-            }
-
             forEach(node.elementTypes, checkSourceElement);
         }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
@@ -2651,9 +2651,9 @@ namespace ts {
         AllowQualifedNameInPlaceOfIdentifier    = 1 << 11,
         AllowAnonymousIdentifier                = 1 << 13,
         AllowEmptyUnionOrIntersection           = 1 << 14,
-        AllowEmptyTuple                         = 1 << 15,
+        // AllowEmptyTuple                         = 1 << 15,
 
-        IgnoreErrors = AllowThisInObjectLiteral | AllowQualifedNameInPlaceOfIdentifier | AllowAnonymousIdentifier | AllowEmptyUnionOrIntersection | AllowEmptyTuple,
+        IgnoreErrors = AllowThisInObjectLiteral | AllowQualifedNameInPlaceOfIdentifier | AllowAnonymousIdentifier | AllowEmptyUnionOrIntersection,
 
         // State
         InObjectTypeLiteral                     = 1 << 20,
diff --git a/tests/baselines/reference/TupleType3.errors.txt b/tests/baselines/reference/TupleType3.errors.txt
diff --git a/tests/baselines/reference/TupleType3.symbols b/tests/baselines/reference/TupleType3.symbols
@@ -0,0 +1,4 @@
+=== tests/cases/conformance/parser/ecmascript5/TupleTypes/TupleType3.ts ===
+var v: []
+>v : Symbol(v, Decl(TupleType3.ts, 0, 3))
+
diff --git a/tests/baselines/reference/TupleType3.types b/tests/baselines/reference/TupleType3.types
@@ -0,0 +1,4 @@
+=== tests/cases/conformance/parser/ecmascript5/TupleTypes/TupleType3.ts ===
+var v: []
+>v : []
+
diff --git 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.
     
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion01.errors.txt b/tests/baselines/reference/emptyTuplesTypeAssertion01.errors.txt
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion01.symbols b/tests/baselines/reference/emptyTuplesTypeAssertion01.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion01.ts ===
+let x = <[]>[];
+>x : Symbol(x, Decl(emptyTuplesTypeAssertion01.ts, 0, 3))
+
+let y = x[0];
+>y : Symbol(y, Decl(emptyTuplesTypeAssertion01.ts, 1, 3))
+>x : Symbol(x, Decl(emptyTuplesTypeAssertion01.ts, 0, 3))
+
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion01.types b/tests/baselines/reference/emptyTuplesTypeAssertion01.types
@@ -0,0 +1,12 @@
+=== tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion01.ts ===
+let x = <[]>[];
+>x : []
+><[]>[] : []
+>[] : undefined[]
+
+let y = x[0];
+>y : never
+>x[0] : never
+>x : []
+>0 : 0
+
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion02.errors.txt b/tests/baselines/reference/emptyTuplesTypeAssertion02.errors.txt
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion02.symbols b/tests/baselines/reference/emptyTuplesTypeAssertion02.symbols
@@ -0,0 +1,8 @@
+=== tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion02.ts ===
+let x = [] as [];
+>x : Symbol(x, Decl(emptyTuplesTypeAssertion02.ts, 0, 3))
+
+let y = x[0];
+>y : Symbol(y, Decl(emptyTuplesTypeAssertion02.ts, 1, 3))
+>x : Symbol(x, Decl(emptyTuplesTypeAssertion02.ts, 0, 3))
+
diff --git a/tests/baselines/reference/emptyTuplesTypeAssertion02.types b/tests/baselines/reference/emptyTuplesTypeAssertion02.types
@@ -0,0 +1,12 @@
+=== tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion02.ts ===
+let x = [] as [];
+>x : []
+>[] as [] : []
+>[] : undefined[]
+
+let y = x[0];
+>y : never
+>x[0] : never
+>x : []
+>0 : 0
+
diff --git 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"'.
@@ -29,7 +28,7 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(76,5): error
 tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(77,5): error TS2322: Type 'keyof (T & U)' is not assignable to type 'keyof (T | U)'.
 
 
-==== tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts (25 errors) ====
+==== tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts (24 errors) ====
     class Shape {
         name: string;
         width: number;
@@ -113,8 +112,6 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(77,5): 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
@@ -1,14 +1,11 @@
-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 'pop' are incompatible.
     Type '() => any' is not assignable to type '() => never'.
       Type 'any' is not assignable to type 'never'.
 
 
-==== 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/cases/compiler/tupleTypes.ts b/tests/cases/compiler/tupleTypes.ts
@@ -1,7 +1,8 @@
-var v1: [];  // Error
+var v1: [] = [];
 var v2: [number];
 var v3: [number, string];
 var v4: [number, [string, string]];
+var v5: number[] = v1;
 
 var t: [number, string];
 var t0 = t[0];   // number

Original file line number	Diff line number	Diff line change
`@@ -2646,11 +2646,7 @@ namespace ts {`
`2646`	`2646`	`return createTupleTypeNode(tupleConstituentNodes);`
`2647`	`2647`	`}`
`2648`	`2648`	`}`
`2649`		`- if (context.encounteredError \|\| (context.flags & NodeBuilderFlags.AllowEmptyTuple)) {`
`2650`		`- return createTupleTypeNode([]);`
`2651`		`- }`
`2652`		`- context.encounteredError = true;`
`2653`		`- return undefined;`
	`2649`	`+ return createTupleTypeNode([]);`
`2654`	`2650`	`}`
`2655`	`2651`	`else {`
`2656`	`2652`	`const outerTypeParameters = type.target.outerTypeParameters;`
`@@ -18737,10 +18733,6 @@ namespace ts {`
`18737`	`18733`	`function checkTupleType(node: TupleTypeNode) {`
`18738`	`18734`	`// Grammar checking`
`18739`	`18735`	`const hasErrorFromDisallowedTrailingComma = checkGrammarForDisallowedTrailingComma(node.elementTypes);`
`18740`		`- if (!hasErrorFromDisallowedTrailingComma && node.elementTypes.length === 0) {`
`18741`		`- grammarErrorOnNode(node, Diagnostics.A_tuple_type_element_list_cannot_be_empty);`
`18742`		`- }`
`18743`		`-`
`18744`	`18736`	`forEach(node.elementTypes, checkSourceElement);`
`18745`	`18737`	`}`
`18746`	`18738`
-Original file line number
+Diff line change
@@ @@ -0,0 +1,4 @@ @@
 +=== tests/cases/conformance/parser/ecmascript5/TupleTypes/TupleType3.ts ===
 +var v: []
 +>v : []
++