@env0/dynamo-easy
Version:
DynamoDB client for NodeJS and browser with a fluent api to build requests. We take care of the type mapping between JS and DynamoDB, customizable trough typescript decorators.
48 lines • 2.2 kB
JavaScript
import { uniqueAttributeValueName } from '../functions/unique-attribute-value-name.function';
/**
* @hidden
*/
export function mergeConditions(operator, conditionDefinitionFns) {
return (expressionAttributeValues, metadata) => {
const mergedCondition = {
statement: '',
attributeNames: {},
attributeValues: {},
};
const statements = [];
conditionDefinitionFns.forEach(conditionDefinitionFn => {
// we can reuse the same for multiple conditions
const condition = conditionDefinitionFn(expressionAttributeValues, metadata);
mergedCondition.attributeNames = Object.assign({}, mergedCondition.attributeNames, condition.attributeNames);
/*
* we need to make sure the value variable name is unique, this wont' work so the second :name must be renamed
* {
* ":name" : { S: "the name" },
* ":name" : { S: "other name" }
* }
* |
* |
* ▽
* {
* ":name" : { S: "the name" },
* ":name_2" : { S: "other name" }
* }
*
*/
const attributeValues = {};
Object.keys(condition.attributeValues).forEach(key => {
const unique = uniqueAttributeValueName(key.replace(':', ''), Object.keys(mergedCondition.attributeValues));
if (key !== unique) {
// rename of the attributeName is required in condition
condition.statement = condition.statement.replace(key, unique);
}
attributeValues[unique] = condition.attributeValues[key];
});
mergedCondition.attributeValues = Object.assign({}, mergedCondition.attributeValues, attributeValues);
statements.push(condition.statement);
});
mergedCondition.statement = statements.length === 1 ? statements[0] : `(${statements.join(' ' + operator + ' ')})`;
return mergedCondition;
};
}
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