Merge pull request #9170 from Microsoft/emptyTupleAssertions

Correctly check types in type assertions

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -11524,7 +11524,10 @@ namespace ts {
 
         function checkAssertion(node: AssertionExpression) {
             const exprType = getRegularTypeOfObjectLiteral(checkExpression(node.expression));
+
+            checkSourceElement(node.type);
             const targetType = getTypeFromTypeNode(node.type);
+
             if (produceDiagnostics && targetType !== unknownType) {
                 const widenedType = getWidenedType(exprType);
                 if (!isTypeComparableTo(targetType, widenedType)) {

tests/baselines/reference/defaultValueInFunctionTypes.errors.txt

@@ -1,8 +1,11 @@
 tests/cases/compiler/defaultValueInFunctionTypes.ts(1,9): error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
+tests/cases/compiler/defaultValueInFunctionTypes.ts(2,11): error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
 
 
-==== tests/cases/compiler/defaultValueInFunctionTypes.ts (1 errors) ====
+==== tests/cases/compiler/defaultValueInFunctionTypes.ts (2 errors) ====
     var x: (a: number = 1) => number;
             ~~~~~~~~~~~~~
 !!! error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
-    var y = <(a : string = "") => any>(undefined)
+    var y = <(a : string = "") => any>(undefined)
+              ~~~~~~~~~~~~~~~
+!!! error TS2371: A parameter initializer is only allowed in a function or constructor implementation.

tests/baselines/reference/duplicatePropertiesInTypeAssertions01.errors.txt

@@ -0,0 +1,11 @@
+tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions01.ts(2,11): error TS2300: Duplicate identifier 'a'.
+tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions01.ts(2,22): error TS2300: Duplicate identifier 'a'.
+
+
+==== tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions01.ts (2 errors) ====
+    
+    let x = <{a: number; a: number}>{};
+              ~
+!!! error TS2300: Duplicate identifier 'a'.
+                         ~
+!!! error TS2300: Duplicate identifier 'a'.

tests/baselines/reference/duplicatePropertiesInTypeAssertions01.js

@@ -0,0 +1,12 @@
+//// [duplicatePropertiesInTypeAssertions01.ts]
+
+let x = <{a: number; a: number}>{};
+
+//// [duplicatePropertiesInTypeAssertions01.js]
+var x = {};
+
+
+//// [duplicatePropertiesInTypeAssertions01.d.ts]
+declare let x: {
+    a: number;
+};

tests/baselines/reference/duplicatePropertiesInTypeAssertions02.errors.txt

@@ -0,0 +1,11 @@
+tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions02.ts(2,16): error TS2300: Duplicate identifier 'a'.
+tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions02.ts(2,27): error TS2300: Duplicate identifier 'a'.
+
+
+==== tests/cases/conformance/expressions/typeAssertions/duplicatePropertiesInTypeAssertions02.ts (2 errors) ====
+    
+    let x = {} as {a: number; a: number};
+                   ~
+!!! error TS2300: Duplicate identifier 'a'.
+                              ~
+!!! error TS2300: Duplicate identifier 'a'.

tests/baselines/reference/duplicatePropertiesInTypeAssertions02.js

@@ -0,0 +1,12 @@
+//// [duplicatePropertiesInTypeAssertions02.ts]
+
+let x = {} as {a: number; a: number};
+
+//// [duplicatePropertiesInTypeAssertions02.js]
+var x = {};
+
+
+//// [duplicatePropertiesInTypeAssertions02.d.ts]
+declare let x: {
+    a: number;
+};

tests/baselines/reference/emptyTuplesTypeAssertion01.errors.txt

@@ -0,0 +1,9 @@
+tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion01.ts(2,10): 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];

tests/baselines/reference/emptyTuplesTypeAssertion01.js

@@ -0,0 +1,13 @@
+//// [emptyTuplesTypeAssertion01.ts]
+
+let x = <[]>[];
+let y = x[0];
+
+//// [emptyTuplesTypeAssertion01.js]
+var x = [];
+var y = x[0];
+
+
+//// [emptyTuplesTypeAssertion01.d.ts]
+declare let x: [];
+declare let y: never;

tests/baselines/reference/emptyTuplesTypeAssertion02.errors.txt

@@ -0,0 +1,9 @@
+tests/cases/conformance/types/tuple/emptyTuples/emptyTuplesTypeAssertion02.ts(2,15): 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];

tests/baselines/reference/emptyTuplesTypeAssertion02.js

@@ -0,0 +1,13 @@
+//// [emptyTuplesTypeAssertion02.ts]
+
+let x = [] as [];
+let y = x[0];
+
+//// [emptyTuplesTypeAssertion02.js]
+var x = [];
+var y = x[0];
+
+
+//// [emptyTuplesTypeAssertion02.d.ts]
+declare let x: [];
+declare let y: never;