Function getIndexedAccessTypeOrUndefined

test/fixtures/snapshot/typescript.js:62405–62470

(objectType, indexType, accessFlags, accessNode, aliasSymbol, aliasTypeArguments)

            });
        }
        function getIndexedAccessTypeOrUndefined(objectType, indexType, accessFlags, accessNode, aliasSymbol, aliasTypeArguments) {
            if (accessFlags === void 0) { accessFlags = 0 /* AccessFlags.None */; }
            if (objectType === wildcardType || indexType === wildcardType) {
                return wildcardType;
            }
            // If the object type has a string index signature and no other members we know that the result will
            // always be the type of that index signature and we can simplify accordingly.
            if (isStringIndexSignatureOnlyType(objectType) && !(indexType.flags & 98304 /* TypeFlags.Nullable */) && isTypeAssignableToKind(indexType, 4 /* TypeFlags.String */ | 8 /* TypeFlags.Number */)) {
                indexType = stringType;
            }
            // In noUncheckedIndexedAccess mode, indexed access operations that occur in an expression in a read position and resolve to
            // an index signature have 'undefined' included in their type.
            if (compilerOptions.noUncheckedIndexedAccess && accessFlags & 32 /* AccessFlags.ExpressionPosition */)
                accessFlags |= 1 /* AccessFlags.IncludeUndefined */;
            // If the index type is generic, or if the object type is generic and doesn't originate in an expression and
            // the operation isn't exclusively indexing the fixed (non-variadic) portion of a tuple type, we are performing
            // a higher-order index access where we cannot meaningfully access the properties of the object type. Note that
            // for a generic T and a non-generic K, we eagerly resolve T[K] if it originates in an expression. This is to
            // preserve backwards compatibility. For example, an element access 'this["foo"]' has always been resolved
            // eagerly using the constraint type of 'this' at the given location.
            if (isGenericIndexType(indexType) || (accessNode && accessNode.kind !== 194 /* SyntaxKind.IndexedAccessType */ ?
                isGenericTupleType(objectType) && !indexTypeLessThan(indexType, objectType.target.fixedLength) :
                isGenericObjectType(objectType) && !(isTupleType(objectType) && indexTypeLessThan(indexType, objectType.target.fixedLength)))) {
                if (objectType.flags & 3 /* TypeFlags.AnyOrUnknown */) {
                    return objectType;
                }
                // Defer the operation by creating an indexed access type.
                var persistentAccessFlags = accessFlags & 1 /* AccessFlags.Persistent */;
                var id = objectType.id + "," + indexType.id + "," + persistentAccessFlags + getAliasId(aliasSymbol, aliasTypeArguments);
                var type = indexedAccessTypes.get(id);
                if (!type) {
                    indexedAccessTypes.set(id, type = createIndexedAccessType(objectType, indexType, persistentAccessFlags, aliasSymbol, aliasTypeArguments));
                }
                return type;
            }
            // In the following we resolve T[K] to the type of the property in T selected by K.
            // We treat boolean as different from other unions to improve errors;
            // skipping straight to getPropertyTypeForIndexType gives errors with 'boolean' instead of 'true'.
            var apparentObjectType = getReducedApparentType(objectType);
            if (indexType.flags & 1048576 /* TypeFlags.Union */ && !(indexType.flags & 16 /* TypeFlags.Boolean */)) {
                var propTypes = [];
                var wasMissingProp = false;
                for (var _i = 0, _a = indexType.types; _i < _a.length; _i++) {
                    var t = _a[_i];
                    var propType = getPropertyTypeForIndexType(objectType, apparentObjectType, t, indexType, accessNode, accessFlags | (wasMissingProp ? 128 /* AccessFlags.SuppressNoImplicitAnyError */ : 0));
                    if (propType) {
                        propTypes.push(propType);
                    }
                    else if (!accessNode) {
                        // If there's no error node, we can immeditely stop, since error reporting is off
                        return undefined;
                    }
                    else {
                        // Otherwise we set a flag and return at the end of the loop so we still mark all errors
                        wasMissingProp = true;
                    }
                }
                if (wasMissingProp) {