Function getTypeOfPropertyOfContextualType

test/fixtures/snapshot/typescript.js:72762–72788

(type, name, nameType)

            return !!(ts.getCheckFlags(symbol) & 262144 /* CheckFlags.Mapped */ && !symbol.type && findResolutionCycleStartIndex(symbol, 0 /* TypeSystemPropertyName.Type */) >= 0);
        }
        function getTypeOfPropertyOfContextualType(type, name, nameType) {
            return mapType(type, function (t) {
                var _a;
                if (isGenericMappedType(t) && !t.declaration.nameType) {
                    var constraint = getConstraintTypeFromMappedType(t);
                    var constraintOfConstraint = getBaseConstraintOfType(constraint) || constraint;
                    var propertyNameType = nameType || getStringLiteralType(ts.unescapeLeadingUnderscores(name));
                    if (isTypeAssignableTo(propertyNameType, constraintOfConstraint)) {
                        return substituteIndexedMappedType(t, propertyNameType);
                    }
                }
                else if (t.flags & 3670016 /* TypeFlags.StructuredType */) {
                    var prop = getPropertyOfType(t, name);
                    if (prop) {
                        return isCircularMappedProperty(prop) ? undefined : getTypeOfSymbol(prop);
                    }
                    if (isTupleType(t)) {
                        var restType = getRestTypeOfTupleType(t);
                        if (restType && ts.isNumericLiteralName(name) && +name >= 0) {
                            return restType;
                        }
                    }
                    return (_a = findApplicableIndexInfo(getIndexInfosOfStructuredType(t), nameType || getStringLiteralType(ts.unescapeLeadingUnderscores(name)))) === null || _a === void 0 ? void 0 : _a.type;
                }
                return undefined;
            }, /*noReductions*/ true);
        }
        // In an object literal contextually typed by a type T, the contextual type of a property assignment is the type of
        // the matching property in T, if one exists. Otherwise, it is the type of the numeric index signature in T, if one
        // exists. Otherwise, it is the type of the string index signature in T, if one exists.