Function elaborateElementwise

test/fixtures/snapshot/typescript.js:64014–64073

* For every element returned from the iterator, checks that element to issue an error on a property of that element's type * If that element would issue an error, we first attempt to dive into that element's inner expression and issue a more specific error by recuring into `elaborateError`

(iterator, source, target, relation, containingMessageChain, errorOutputContainer)

         * Otherwise, we issue an error on _every_ element which fail the assignability check
         */
        function elaborateElementwise(iterator, source, target, relation, containingMessageChain, errorOutputContainer) {
            // Assignability failure - check each prop individually, and if that fails, fall back on the bad error span
            var reportedError = false;
            for (var status = iterator.next(); !status.done; status = iterator.next()) {
                var _a = status.value, prop = _a.errorNode, next = _a.innerExpression, nameType = _a.nameType, errorMessage = _a.errorMessage;
                var targetPropType = getBestMatchIndexedAccessTypeOrUndefined(source, target, nameType);
                if (!targetPropType || targetPropType.flags & 8388608 /* TypeFlags.IndexedAccess */)
                    continue; // Don't elaborate on indexes on generic variables
                var sourcePropType = getIndexedAccessTypeOrUndefined(source, nameType);
                if (!sourcePropType)
                    continue;
                var propName = getPropertyNameFromIndex(nameType, /*accessNode*/ undefined);
                if (!checkTypeRelatedTo(sourcePropType, targetPropType, relation, /*errorNode*/ undefined)) {
                    var elaborated = next && elaborateError(next, sourcePropType, targetPropType, relation, /*headMessage*/ undefined, containingMessageChain, errorOutputContainer);
                    reportedError = true;
                    if (!elaborated) {
                        // Issue error on the prop itself, since the prop couldn't elaborate the error
                        var resultObj = errorOutputContainer || {};
                        // Use the expression type, if available
                        var specificSource = next ? checkExpressionForMutableLocationWithContextualType(next, sourcePropType) : sourcePropType;
                        if (exactOptionalPropertyTypes && isExactOptionalPropertyMismatch(specificSource, targetPropType)) {
                            var diag = ts.createDiagnosticForNode(prop, ts.Diagnostics.Type_0_is_not_assignable_to_type_1_with_exactOptionalPropertyTypes_Colon_true_Consider_adding_undefined_to_the_type_of_the_target, typeToString(specificSource), typeToString(targetPropType));
                            diagnostics.add(diag);
                            resultObj.errors = [diag];
                        }
                        else {
                            var targetIsOptional = !!(propName && (getPropertyOfType(target, propName) || unknownSymbol).flags & 16777216 /* SymbolFlags.Optional */);
                            var sourceIsOptional = !!(propName && (getPropertyOfType(source, propName) || unknownSymbol).flags & 16777216 /* SymbolFlags.Optional */);
                            targetPropType = removeMissingType(targetPropType, targetIsOptional);
                            sourcePropType = removeMissingType(sourcePropType, targetIsOptional && sourceIsOptional);
                            var result = checkTypeRelatedTo(specificSource, targetPropType, relation, prop, errorMessage, containingMessageChain, resultObj);
                            if (result && specificSource !== sourcePropType) {
                                // If for whatever reason the expression type doesn't yield an error, make sure we still issue an error on the sourcePropType
                                checkTypeRelatedTo(sourcePropType, targetPropType, relation, prop, errorMessage, containingMessageChain, resultObj);
                            }
                        }
                        if (resultObj.errors) {
                            var reportedDiag = resultObj.errors[resultObj.errors.length - 1];
                            var propertyName = isTypeUsableAsPropertyName(nameType) ? getPropertyNameFromType(nameType) : undefined;
                            var targetProp = propertyName !== undefined ? getPropertyOfType(target, propertyName) : undefined;
                            var issuedElaboration = false;
                            if (!targetProp) {
                                var indexInfo = getApplicableIndexInfo(target, nameType);
                                if (indexInfo && indexInfo.declaration && !ts.getSourceFileOfNode(indexInfo.declaration).hasNoDefaultLib) {
                                    issuedElaboration = true;
                                    ts.addRelatedInfo(reportedDiag, ts.createDiagnosticForNode(indexInfo.declaration, ts.Diagnostics.The_expected_type_comes_from_this_index_signature));
                                }
                            }
                            if (!issuedElaboration && (targetProp && ts.length(targetProp.declarations) || target.symbol && ts.length(target.symbol.declarations))) {
                                var targetNode = targetProp && ts.length(targetProp.declarations) ? targetProp.declarations[0] : target.symbol.declarations[0];
                                if (!ts.getSourceFileOfNode(targetNode).hasNoDefaultLib) {
                                    ts.addRelatedInfo(reportedDiag, ts.createDiagnosticForNode(targetNode, ts.Diagnostics.The_expected_type_comes_from_property_0_which_is_declared_here_on_type_1, propertyName && !(nameType.flags & 8192 /* TypeFlags.UniqueESSymbol */) ? ts.unescapeLeadingUnderscores(propertyName) : typeToString(nameType), typeToString(target)));
                                }
                            }
                        }
                    }
                }
            }