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Merge pull request #5992 from Microsoft/allow-type-predicates-as-return-types-only

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Allow type predicates as return types only
This commit is contained in:
Nathan Shively-Sanders
2016-01-13 09:55:40 -08:00
parent 5f024a3c9f a9f2cb6d6e
commit 911d07a81b
8 changed files with 281 additions and 143 deletions
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src/compiler/checker.ts
+73 -88
View File
@@ -11187,7 +11187,53 @@ namespace ts {
return -1;
}
function isInLegalParameterTypePredicatePosition(node: Node): boolean {
function checkTypePredicate(node: TypePredicateNode) {
const parent = getTypePredicateParent(node);
if (!parent) {
return;
}
const returnType = getReturnTypeOfSignature(getSignatureFromDeclaration(parent));
if (!returnType || !(returnType.flags & TypeFlags.PredicateType)) {
return;
}
const { parameterName } = node;
if (parameterName.kind === SyntaxKind.ThisType) {
getTypeFromThisTypeNode(parameterName as ThisTypeNode);
}
else {
const typePredicate = <IdentifierTypePredicate>(<PredicateType>returnType).predicate;
if (typePredicate.parameterIndex >= 0) {
if (parent.parameters[typePredicate.parameterIndex].dotDotDotToken) {
error(parameterName,
Diagnostics.A_type_predicate_cannot_reference_a_rest_parameter);
}
else {
checkTypeAssignableTo(typePredicate.type,
getTypeOfNode(parent.parameters[typePredicate.parameterIndex]),
node.type);
}
}
else if (parameterName) {
let hasReportedError = false;
for (const { name } of parent.parameters) {
if ((name.kind === SyntaxKind.ObjectBindingPattern ||
name.kind === SyntaxKind.ArrayBindingPattern) &&
checkIfTypePredicateVariableIsDeclaredInBindingPattern(
<BindingPattern>name,
parameterName,
typePredicate.parameterName)) {
hasReportedError = true;
break;
}
}
if (!hasReportedError) {
error(node.parameterName, Diagnostics.Cannot_find_parameter_0, typePredicate.parameterName);
}
}
}
}
function getTypePredicateParent(node: Node): SignatureDeclaration {
switch (node.parent.kind) {
case SyntaxKind.ArrowFunction:
case SyntaxKind.CallSignature:
@@ -11196,22 +11242,35 @@ namespace ts {
case SyntaxKind.FunctionType:
case SyntaxKind.MethodDeclaration:
case SyntaxKind.MethodSignature:
return node === (<SignatureDeclaration>node.parent).type;
const parent = <SignatureDeclaration>node.parent;
if (node === parent.type) {
return parent;
}
}
return false;
}
function isInLegalThisTypePredicatePosition(node: Node): boolean {
if (isInLegalParameterTypePredicatePosition(node)) {
return true;
function checkIfTypePredicateVariableIsDeclaredInBindingPattern(
pattern: BindingPattern,
predicateVariableNode: Node,
predicateVariableName: string) {
for (const { name } of pattern.elements) {
if (name.kind === SyntaxKind.Identifier &&
(<Identifier>name).text === predicateVariableName) {
error(predicateVariableNode,
Diagnostics.A_type_predicate_cannot_reference_element_0_in_a_binding_pattern,
predicateVariableName);
return true;
}
else if (name.kind === SyntaxKind.ArrayBindingPattern ||
name.kind === SyntaxKind.ObjectBindingPattern) {
if (checkIfTypePredicateVariableIsDeclaredInBindingPattern(
<BindingPattern>name,
predicateVariableNode,
predicateVariableName)) {
return true;
}
}
}
switch (node.parent.kind) {
case SyntaxKind.PropertyDeclaration:
case SyntaxKind.PropertySignature:
case SyntaxKind.GetAccessor:
return node === (node.parent as (PropertyDeclaration | GetAccessorDeclaration | PropertySignature)).type;
}
return false;
}
function checkSignatureDeclaration(node: SignatureDeclaration) {
@@ -11230,68 +11289,8 @@ namespace ts {
forEach(node.parameters, checkParameter);
if (node.type) {
if (node.type.kind === SyntaxKind.TypePredicate) {
const returnType = getReturnTypeOfSignature(getSignatureFromDeclaration(node));
if (!returnType || !(returnType.flags & TypeFlags.PredicateType)) {
return;
}
const typePredicate = (returnType as PredicateType).predicate;
const typePredicateNode = node.type as TypePredicateNode;
checkSourceElement(typePredicateNode);
if (isIdentifierTypePredicate(typePredicate)) {
if (typePredicate.parameterIndex >= 0) {
if (node.parameters[typePredicate.parameterIndex].dotDotDotToken) {
error(typePredicateNode.parameterName,
Diagnostics.A_type_predicate_cannot_reference_a_rest_parameter);
}
else {
checkTypeAssignableTo(typePredicate.type,
getTypeOfNode(node.parameters[typePredicate.parameterIndex]),
typePredicateNode.type);
}
}
else if (typePredicateNode.parameterName) {
let hasReportedError = false;
for (var param of node.parameters) {
if (hasReportedError) {
break;
}
if (param.name.kind === SyntaxKind.ObjectBindingPattern ||
param.name.kind === SyntaxKind.ArrayBindingPattern) {
checkSourceElement(node.type);
(function checkBindingPattern(pattern: BindingPattern) {
for (const element of pattern.elements) {
if (element.name.kind === SyntaxKind.Identifier &&
(<Identifier>element.name).text === typePredicate.parameterName) {
error(typePredicateNode.parameterName,
Diagnostics.A_type_predicate_cannot_reference_element_0_in_a_binding_pattern,
typePredicate.parameterName);
hasReportedError = true;
break;
}
else if (element.name.kind === SyntaxKind.ArrayBindingPattern ||
element.name.kind === SyntaxKind.ObjectBindingPattern) {
checkBindingPattern(<BindingPattern>element.name);
}
}
})(<BindingPattern>param.name);
}
}
if (!hasReportedError) {
error(typePredicateNode.parameterName,
Diagnostics.Cannot_find_parameter_0,
typePredicate.parameterName);
}
}
}
}
else {
checkSourceElement(node.type);
}
}
if (produceDiagnostics) {
checkCollisionWithArgumentsInGeneratedCode(node);
@@ -14460,20 +14459,6 @@ namespace ts {
}
}
function checkTypePredicate(node: TypePredicateNode) {
const { parameterName } = node;
if (parameterName.kind === SyntaxKind.Identifier && !isInLegalParameterTypePredicatePosition(node)) {
error(node, Diagnostics.A_type_predicate_is_only_allowed_in_return_type_position_for_functions_and_methods);
}
else if (parameterName.kind === SyntaxKind.ThisType) {
if (!isInLegalThisTypePredicatePosition(node)) {
error(node, Diagnostics.A_this_based_type_predicate_is_only_allowed_within_a_class_or_interface_s_members_get_accessors_or_return_type_positions_for_functions_and_methods);
}
else {
getTypeFromThisTypeNode(parameterName as ThisTypeNode);
}
}
}
function checkSourceElement(node: Node): void {
if (!node) {
src/compiler/diagnosticMessages.json
-8
View File
@@ -711,10 +711,6 @@
"category": "Error",
"code": 1227
},
"A type predicate is only allowed in return type position for functions and methods.": {
"category": "Error",
"code": 1228
},
"A type predicate cannot reference a rest parameter.": {
"category": "Error",
"code": 1229
@@ -1655,10 +1651,6 @@
"category": "Error",
"code": 2518
},
"A 'this'-based type predicate is only allowed within a class or interface's members, get accessors, or return type positions for functions and methods.": {
"category": "Error",
"code": 2519
},
"Duplicate identifier '{0}'. Compiler uses declaration '{1}' to support async functions.": {
"category": "Error",
"code": 2520
src/compiler/parser.ts
+36 -15
View File
@@ -896,17 +896,19 @@ namespace ts {
return result;
}
// Invokes the provided callback then unconditionally restores the parser to the state it
// was in immediately prior to invoking the callback. The result of invoking the callback
// is returned from this function.
/** Invokes the provided callback then unconditionally restores the parser to the state it
* was in immediately prior to invoking the callback. The result of invoking the callback
* is returned from this function.
*/
function lookAhead<T>(callback: () => T): T {
return speculationHelper(callback, /*isLookAhead*/ true);
}
// Invokes the provided callback. If the callback returns something falsy, then it restores
// the parser to the state it was in immediately prior to invoking the callback. If the
// callback returns something truthy, then the parser state is not rolled back. The result
// of invoking the callback is returned from this function.
/** Invokes the provided callback. If the callback returns something falsy, then it restores
* the parser to the state it was in immediately prior to invoking the callback. If the
* callback returns something truthy, then the parser state is not rolled back. The result
* of invoking the callback is returned from this function.
*/
function tryParse<T>(callback: () => T): T {
return speculationHelper(callback, /*isLookAhead*/ false);
}
@@ -1948,11 +1950,8 @@ namespace ts {
// TYPES
function parseTypeReferenceOrTypePredicate(): TypeReferenceNode | TypePredicateNode {
function parseTypeReference(): TypeReferenceNode {
const typeName = parseEntityName(/*allowReservedWords*/ false, Diagnostics.Type_expected);
if (typeName.kind === SyntaxKind.Identifier && token === SyntaxKind.IsKeyword && !scanner.hasPrecedingLineBreak()) {
return parseTypePredicate(typeName as Identifier);
}
const node = <TypeReferenceNode>createNode(SyntaxKind.TypeReference, typeName.pos);
node.typeName = typeName;
if (!scanner.hasPrecedingLineBreak() && token === SyntaxKind.LessThanToken) {
@@ -2092,10 +2091,10 @@ namespace ts {
if (returnTokenRequired) {
parseExpected(returnToken);
signature.type = parseType();
signature.type = parseTypeOrTypePredicate();
}
else if (parseOptional(returnToken)) {
signature.type = parseType();
signature.type = parseTypeOrTypePredicate();
}
}
@@ -2411,7 +2410,7 @@ namespace ts {
case SyntaxKind.SymbolKeyword:
// If these are followed by a dot, then parse these out as a dotted type reference instead.
const node = tryParse(parseKeywordAndNoDot);
return node || parseTypeReferenceOrTypePredicate();
return node || parseTypeReference();
case SyntaxKind.StringLiteral:
return parseStringLiteralTypeNode();
case SyntaxKind.VoidKeyword:
@@ -2434,7 +2433,7 @@ namespace ts {
case SyntaxKind.OpenParenToken:
return parseParenthesizedType();
default:
return parseTypeReferenceOrTypePredicate();
return parseTypeReference();
}
}
@@ -2541,6 +2540,28 @@ namespace ts {
return false;
}
function parseTypeOrTypePredicate(): TypeNode {
const typePredicateVariable = isIdentifier() && tryParse(parseTypePredicatePrefix);
const type = parseType();
if (typePredicateVariable) {
const node = <TypePredicateNode>createNode(SyntaxKind.TypePredicate, typePredicateVariable.pos);
node.parameterName = typePredicateVariable;
node.type = type;
return finishNode(node);
}
else {
return type;
}
}
function parseTypePredicatePrefix() {
const id = parseIdentifier();
if (token === SyntaxKind.IsKeyword && !scanner.hasPrecedingLineBreak()) {
nextToken();
return id;
}
}
function parseType(): TypeNode {
// The rules about 'yield' only apply to actual code/expression contexts. They don't
// apply to 'type' contexts. So we disable these parameters here before moving on.
tests/baselines/reference/typeAssertions.errors.txt
+51 -1
View File
@@ -7,9 +7,23 @@ tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(37,13): err
Property 'q' is missing in type 'SomeDerived'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(38,13): error TS2352: Neither type 'SomeBase' nor type 'SomeOther' is assignable to the other.
Property 'q' is missing in type 'SomeBase'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,5): error TS2304: Cannot find name 'numOrStr'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,14): error TS1005: '>' expected.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,14): error TS2304: Cannot find name 'is'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,17): error TS1005: ')' expected.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,17): error TS2304: Cannot find name 'string'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(44,48): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(45,2): error TS2322: Type 'number | string' is not assignable to type 'string'.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,32): error TS2304: Cannot find name 'numOrStr'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,41): error TS1005: ')' expected.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,41): error TS2304: Cannot find name 'is'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,44): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,44): error TS2304: Cannot find name 'string'.
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(48,50): error TS1005: ';' expected.
==== tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts (5 errors) ====
==== tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts (18 errors) ====
// Function call whose argument is a 1 arg generic function call with explicit type arguments
function fn1<T>(t: T) { }
function fn2(t: any) { }
@@ -64,5 +78,41 @@ tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts(38,13): err
!!! error TS2352: Property 'q' is missing in type 'SomeBase'.
someOther = <SomeOther>someOther;
// Type assertion cannot be a type-predicate type
var numOrStr: number | string;
var str: string;
if(<numOrStr is string>(numOrStr === undefined)) { // Error
~~~~~~~~
!!! error TS2304: Cannot find name 'numOrStr'.
~~
!!! error TS1005: '>' expected.
~~
!!! error TS2304: Cannot find name 'is'.
~~~~~~
!!! error TS1005: ')' expected.
~~~~~~
!!! error TS2304: Cannot find name 'string'.
~
!!! error TS1005: ';' expected.
str = numOrStr; // Error, no narrowing occurred
~~~
!!! error TS2322: Type 'number | string' is not assignable to type 'string'.
!!! error TS2322: Type 'number' is not assignable to type 'string'.
}
if((numOrStr === undefined) as numOrStr is string) { // Error
~~~~~~~~
!!! error TS2304: Cannot find name 'numOrStr'.
~~
!!! error TS1005: ')' expected.
~~
!!! error TS2304: Cannot find name 'is'.
~~~~~~
!!! error TS1005: ';' expected.
~~~~~~
!!! error TS2304: Cannot find name 'string'.
~
!!! error TS1005: ';' expected.
}
tests/baselines/reference/typeAssertions.js
+22
View File
@@ -39,6 +39,15 @@ someOther = <SomeOther>someDerived; // Error
someOther = <SomeOther>someBase; // Error
someOther = <SomeOther>someOther;
// Type assertion cannot be a type-predicate type
var numOrStr: number | string;
var str: string;
if(<numOrStr is string>(numOrStr === undefined)) { // Error
str = numOrStr; // Error, no narrowing occurred
}
if((numOrStr === undefined) as numOrStr is string) { // Error
}
@@ -87,3 +96,16 @@ someDerived = someOther; // Error
someOther = someDerived; // Error
someOther = someBase; // Error
someOther = someOther;
// Type assertion cannot be a type-predicate type
var numOrStr;
var str;
if (is)
string > (numOrStr === undefined);
{
str = numOrStr; // Error, no narrowing occurred
}
if ((numOrStr === undefined))
is;
string;
{
}
tests/baselines/reference/typeGuardFunctionErrors.errors.txt
+78 -27
View File
@@ -1,15 +1,21 @@
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(2,7): error TS2300: Duplicate identifier 'A'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(15,12): error TS2322: Type 'string' is not assignable to type 'x is A'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,55): error TS2304: Cannot find name 'x'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,57): error TS1144: '{' or ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,57): error TS2304: Cannot find name 'is'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,60): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(18,62): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(22,33): error TS2304: Cannot find name 'x'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(26,33): error TS1225: Cannot find parameter 'x'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(30,10): error TS2391: Function implementation is missing or not immediately following the declaration.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(31,5): error TS1131: Property or signature expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(31,5): error TS7027: Unreachable code detected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(32,1): error TS1128: Declaration or statement expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(34,38): error TS1225: Cannot find parameter 'x'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(38,51): error TS2322: Type 'B' is not assignable to type 'A'.
Property 'propA' is missing in type 'B'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(42,56): error TS2322: Type 'number' is not assignable to type 'string'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(46,56): error TS2322: Type 'T[]' is not assignable to type 'string'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(50,1): error TS7027: Unreachable code detected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(60,7): error TS2339: Property 'propB' does not exist on type 'A'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(65,7): error TS2339: Property 'propB' does not exist on type 'A'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(70,7): error TS2339: Property 'propB' does not exist on type 'A'.
@@ -23,27 +29,40 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(85,1):
Type predicate 'p2 is A' is not assignable to 'p1 is A'.
Parameter 'p2' is not in the same position as parameter 'p1'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(91,1): error TS2322: Type '(p1: any, p2: any, p3: any) => p1 is A' is not assignable to type '(p1: any, p2: any) => p1 is A'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(96,9): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(97,16): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,20): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(96,9): error TS2304: Cannot find name 'b'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(96,11): error TS1005: '=' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(96,11): error TS2304: Cannot find name 'is'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(96,14): error TS1005: ',' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(96,14): error TS2300: Duplicate identifier 'A'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(97,16): error TS2304: Cannot find name 'b'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(97,18): error TS1005: '=' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(97,18): error TS2304: Cannot find name 'is'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(97,21): error TS1005: ',' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,20): error TS2304: Cannot find name 'b'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,22): error TS1144: '{' or ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,22): error TS2304: Cannot find name 'is'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,25): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(98,27): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(105,16): error TS2322: Type 'boolean' is not assignable to type 'D'.
Property 'm1' is missing in type 'Boolean'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(105,16): error TS2409: Return type of constructor signature must be assignable to the instance type of the class
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(107,20): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(110,20): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(111,16): error TS2408: Setters cannot return a value.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(116,18): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,22): error TS1225: Cannot find parameter 'p1'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,22): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,22): error TS2304: Cannot find name 'p1'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,25): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,25): error TS2304: Cannot find name 'is'.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(120,28): error TS1005: ';' expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(121,1): error TS1128: Declaration or statement expected.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(124,20): error TS1229: A type predicate cannot reference a rest parameter.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(129,34): error TS1230: A type predicate cannot reference element 'p1' in a binding pattern.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(133,34): error TS1230: A type predicate cannot reference element 'p1' in a binding pattern.
tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39): error TS1230: A type predicate cannot reference element 'p1' in a binding pattern.
==== tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts (33 errors) ====
==== tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts (50 errors) ====
class A {
~
!!! error TS2300: Duplicate identifier 'A'.
propA: number;
}
@@ -62,6 +81,16 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
}
function hasTypeGuardTypeInsideTypeGuardType(x): x is x is A {
~
!!! error TS2304: Cannot find name 'x'.
~~
!!! error TS1144: '{' or ';' expected.
~~
!!! error TS2304: Cannot find name 'is'.
~
!!! error TS1005: ';' expected.
~
!!! error TS1005: ';' expected.
return true;
}
@@ -83,6 +112,8 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
return true;
~~~~~~
!!! error TS1131: Property or signature expected.
~~~~~~
!!! error TS7027: Unreachable code detected.
}
~
!!! error TS1128: Declaration or statement expected.
@@ -113,8 +144,6 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
}
let a: A;
~~~
!!! error TS7027: Unreachable code detected.
let b: B;
declare function isB(p1): p1 is B;
@@ -181,14 +210,36 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
// Type predicates in non-return type positions
var b1: b is A;
~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
~
!!! error TS2304: Cannot find name 'b'.
~~
!!! error TS1005: '=' expected.
~~
!!! error TS2304: Cannot find name 'is'.
~
!!! error TS1005: ',' expected.
~
!!! error TS2300: Duplicate identifier 'A'.
function b2(a: b is A) {};
~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
~
!!! error TS2304: Cannot find name 'b'.
~~
!!! error TS1005: '=' expected.
~~
!!! error TS2304: Cannot find name 'is'.
~
!!! error TS1005: ',' expected.
function b3(): A | b is A {
~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
~
!!! error TS2304: Cannot find name 'b'.
~~
!!! error TS1144: '{' or ';' expected.
~~
!!! error TS2304: Cannot find name 'is'.
~
!!! error TS1005: ';' expected.
~
!!! error TS1005: ';' expected.
return true;
};
@@ -203,13 +254,9 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
!!! error TS2409: Return type of constructor signature must be assignable to the instance type of the class
}
get m1(p1: A): p1 is C {
~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
return true;
}
set m2(p1: A): p1 is C {
~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
return true;
~~~~
!!! error TS2408: Setters cannot return a value.
@@ -218,17 +265,21 @@ tests/cases/conformance/expressions/typeGuards/typeGuardFunctionErrors.ts(137,39
interface I1 {
new (p1: A): p1 is C;
~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
}
interface I2 {
[index: number]: p1 is C;
~~
!!! error TS1225: Cannot find parameter 'p1'.
~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
!!! error TS2304: Cannot find name 'p1'.
~~
!!! error TS1005: ';' expected.
~~
!!! error TS2304: Cannot find name 'is'.
~
!!! error TS1005: ';' expected.
}
~
!!! error TS1128: Declaration or statement expected.
// Reference to rest parameter
function b4(...a): a is A {
tests/baselines/reference/typeGuardFunctionErrors.js
+12 -4
View File
@@ -171,7 +171,9 @@ var C = (function (_super) {
function hasANonBooleanReturnStatement(x) {
return '';
}
function hasTypeGuardTypeInsideTypeGuardType(x) {
is;
A;
{
return true;
}
function hasMissingIsKeyword() {
@@ -224,10 +226,14 @@ assign3 = function (p1, p2, p3) {
return true;
};
// Type predicates in non-return type positions
var b1;
function b2(a) { }
var b1 = is, A;
function b2(a, A) {
if (a === void 0) { a = is; }
}
;
function b3() {
is;
A;
{
return true;
}
;
@@ -252,6 +258,8 @@ var D = (function () {
});
return D;
}());
is;
C;
// Reference to rest parameter
function b4() {
var a = [];
tests/cases/conformance/expressions/typeAssertions/typeAssertions.ts
+9
View File
@@ -38,4 +38,13 @@ someOther = <SomeOther>someDerived; // Error
someOther = <SomeOther>someBase; // Error
someOther = <SomeOther>someOther;
// Type assertion cannot be a type-predicate type
var numOrStr: number | string;
var str: string;
if(<numOrStr is string>(numOrStr === undefined)) { // Error
str = numOrStr; // Error, no narrowing occurred
}
if((numOrStr === undefined) as numOrStr is string) { // Error
}