Function narrowTypeByOptionality

test/fixtures/snapshot/typescript.js:71388–71397

(type, expr, assumePresent)

                return type;
            }
            function narrowTypeByOptionality(type, expr, assumePresent) {
                if (isMatchingReference(reference, expr)) {
                    return getTypeWithFacts(type, assumePresent ? 2097152 /* TypeFacts.NEUndefinedOrNull */ : 262144 /* TypeFacts.EQUndefinedOrNull */);
                }
                var access = getDiscriminantPropertyAccess(expr, type);
                if (access) {
                    return narrowTypeByDiscriminant(type, access, function (t) { return getTypeWithFacts(t, assumePresent ? 2097152 /* TypeFacts.NEUndefinedOrNull */ : 262144 /* TypeFacts.EQUndefinedOrNull */); });
                }
                return type;
            }
        }
        function getTypeOfSymbolAtLocation(symbol, location) {
            symbol = symbol.exportSymbol || symbol;