Function narrowTypeByTypePredicate

test/fixtures/snapshot/typescript.js:71323–71342

(type, predicate, callExpression, assumeTrue)

                return type;
            }
            function narrowTypeByTypePredicate(type, predicate, callExpression, assumeTrue) {
                // Don't narrow from 'any' if the predicate type is exactly 'Object' or 'Function'
                if (predicate.type && !(isTypeAny(type) && (predicate.type === globalObjectType || predicate.type === globalFunctionType))) {
                    var predicateArgument = getTypePredicateArgument(predicate, callExpression);
                    if (predicateArgument) {
                        if (isMatchingReference(reference, predicateArgument)) {
                            return getNarrowedType(type, predicate.type, assumeTrue, isTypeSubtypeOf);
                        }
                        if (strictNullChecks && assumeTrue && optionalChainContainsReference(predicateArgument, reference) &&
                            !(getTypeFacts(predicate.type) & 65536 /* TypeFacts.EQUndefined */)) {
                            type = getTypeWithFacts(type, 2097152 /* TypeFacts.NEUndefinedOrNull */);
                        }
                        var access = getDiscriminantPropertyAccess(predicateArgument, type);
                        if (access) {
                            return narrowTypeByDiscriminant(type, access, function (t) { return getNarrowedType(t, predicate.type, assumeTrue, isTypeSubtypeOf); });
                        }
                    }
                }
                return type;
            }
            // Narrow the given type based on the given expression having the assumed boolean value. The returned type
            // will be a subtype or the same type as the argument.
            function narrowType(type, expr, assumeTrue) {