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tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(43,9): error TS7027: Unreachable code detected.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(47,9): error TS7027: Unreachable code detected.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(91,9): error TS7027: Unreachable code detected.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(126,9): error TS7027: Unreachable code detected.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(141,9): error TS7027: Unreachable code detected.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(157,37): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(158,37): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(159,37): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(162,15): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(163,15): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(164,15): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(165,15): error TS1228: A type predicate is only allowed in return type position for functions and methods.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(170,5): error TS2775: Assertions require every name in the call target to be declared with an explicit type annotation.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(172,5): error TS2776: Assertions require the call target to be an identifier or qualified name.
tests/cases/conformance/controlFlow/assertionTypePredicates1.ts(174,5): error TS2775: Assertions require every name in the call target to be declared with an explicit type annotation.
==== tests/cases/conformance/controlFlow/assertionTypePredicates1.ts (15 errors) ====
declare function isString(value: unknown): value is string;
declare function isArrayOfStrings(value: unknown): value is string[];
const assert: (value: unknown) => asserts value = value => {}
declare function assertIsString(value: unknown): asserts value is string;
declare function assertIsArrayOfStrings(value: unknown): asserts value is string[];
declare function assertDefined<T>(value: T): asserts value is NonNullable<T>;
function f01(x: unknown) {
if (!!true) {
assert(typeof x === "string");
x.length;
}
if (!!true) {
assert(x instanceof Error);
x.message;
}
if (!!true) {
assert(typeof x === "boolean" || typeof x === "number");
x.toLocaleString;
}
if (!!true) {
assert(isArrayOfStrings(x));
x[0].length;
}
if (!!true) {
assertIsArrayOfStrings(x);
x[0].length;
}
if (!!true) {
assertIsArrayOfStrings(false);
x;
}
if (!!true) {
assert(x === undefined || typeof x === "string");
x; // string | undefined
assertDefined(x);
x; // string
}
if (!!true) {
assert(false);
x; // Unreachable
~~
!!! error TS7027: Unreachable code detected.
}
if (!!true) {
assert(false && x === undefined);
x; // Unreachable
~~
!!! error TS7027: Unreachable code detected.
}
}
function f02(x: string | undefined) {
if (!!true) {
assert(x);
x.length;
}
if (!!true) {
assert(x !== undefined);
x.length;
}
if (!!true) {
assertDefined(x);
x.length;
}
}
function f03(x: string | undefined, assert: (value: unknown) => asserts value) {
assert(x);
x.length;
}
namespace Debug {
export declare function assert(value: unknown, message?: string): asserts value;
export declare function assertDefined<T>(value: T): asserts value is NonNullable<T>;
}
function f10(x: string | undefined) {
if (!!true) {
Debug.assert(x);
x.length;
}
if (!!true) {
Debug.assert(x !== undefined);
x.length;
}
if (!!true) {
Debug.assertDefined(x);
x.length;
}
if (!!true) {
Debug.assert(false);
x; // Unreachable
~~
!!! error TS7027: Unreachable code detected.
}
}
class Test {
assert(value: unknown): asserts value {
if (value) return;
throw new Error();
}
isTest2(): this is Test2 {
return this instanceof Test2;
}
assertIsTest2(): asserts this is Test2 {
if (this instanceof Test2) return;
throw new Error();
}
assertThis(): asserts this {
if (!this) return;
throw new Error();
}
bar() {
this.assertThis();
this;
}
foo(x: unknown) {
this.assert(typeof x === "string");
x.length;
if (this.isTest2()) {
this.z;
}
this.assertIsTest2();
this.z;
}
baz(x: number) {
this.assert(false);
x; // Unreachable
~~
!!! error TS7027: Unreachable code detected.
}
}
class Test2 extends Test {
z = 0;
}
class Derived extends Test {
foo(x: unknown) {
super.assert(typeof x === "string");
x.length;
}
baz(x: number) {
super.assert(false);
x; // Unreachable
~~
!!! error TS7027: Unreachable code detected.
}
}
function f11(items: Test[]) {
for (let item of items) {
if (item.isTest2()) {
item.z;
}
item.assertIsTest2();
item.z;
}
}
// Invalid constructs
declare let Q1: new (x: unknown) => x is string;
~~~~~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
declare let Q2: new (x: boolean) => asserts x;
~~~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
declare let Q3: new (x: unknown) => asserts x is string;
~~~~~~~~~~~~~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
declare class Wat {
get p1(): this is string;
~~~~~~~~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
set p1(x: this is string);
~~~~~~~~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
get p2(): asserts this is string;
~~~~~~~~~~~~~~~~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
set p2(x: asserts this is string);
~~~~~~~~~~~~~~~~~~~~~~
!!! error TS1228: A type predicate is only allowed in return type position for functions and methods.
}
function f20(x: unknown) {
const assert = (value: unknown): asserts value => {}
assert(typeof x === "string"); // Error
~~~~~~
!!! error TS2775: Assertions require every name in the call target to be declared with an explicit type annotation.
!!! related TS2782 tests/cases/conformance/controlFlow/assertionTypePredicates1.ts:169:11: 'assert' needs an explicit type annotation.
const a = [assert];
a[0](typeof x === "string"); // Error
~~~~
!!! error TS2776: Assertions require the call target to be an identifier or qualified name.
const t1 = new Test();
t1.assert(typeof x === "string"); // Error
~~~~~~~~~
!!! error TS2775: Assertions require every name in the call target to be declared with an explicit type annotation.
!!! related TS2782 tests/cases/conformance/controlFlow/assertionTypePredicates1.ts:173:11: 't1' needs an explicit type annotation.
const t2: Test = new Test();
t2.assert(typeof x === "string");
}
// Repro from #35940
interface Thing {
good: boolean;
isGood(): asserts this is GoodThing;
}
interface GoodThing {
good: true;
}
function example1(things: Thing[]) {
for (let thing of things) {
thing.isGood();
thing.good;
}
}
|
