swc/crates/swc_ecma_parser/tests/tsc/stringLiteralCheckedInIf02.ts


type S = "a" | "b";
type T = S[] | S;

function isS(t: T): t is S {
    return t === "a" || t === "b";
}

function f(foo: T) {
    if (isS(foo)) {
        return foo;
    }
    else { 
        return foo[0];
    }
}
-												feat(es): TypeScript 4.2 (#1330)

swc_ecma_ast:
 - Add `is_abstract` to constructor types.

swc_ecma_codegen:
 - Fix codegen of `Bool`.
 - Implement codegen for abstract constructors.

swc_ecma_parser:
- Inline tsc parser test suite.
- Implement parsing of abstract constructor types.
											
										
										
											2021-01-15 13:30:44 +03:00
 								type S = "a" | "b";
 								type T = S[] | S;
 								function isS(t: T): t is S {
 								    return t === "a" || t === "b";
 								}
 								function f(foo: T) {
 								    if (isS(foo)) {
 								        return foo;
 								    }
 								    else {
 								        return foo[0];
 								    }
 								}