@campfhir/object-mapper NPM

Object Mapper

This is a utility that helps with object mapping from one data structure to another with declarative instructions.

APIs

Map
Compare Objects
Coalesce Array Object
Add Parameters to SQL Request (requires mssql)
SQL Parameter Mapping (requires mssql)
SQL Table Parameter Mapping (requires mssql)

Map

This method takes an object and a mapping definition object and returns a new object based on that definition. Can throw an error or array or errors if definition functions throws internally or if options.throwOnFalseValidation is true and the evaluation of validation or pre-validation returns false.

Returns any

Argument/Parameter	Required	Purpose	Default
data	Required	The data to map from, should be an object or array of object
map	Required	The mapping definition to determine how to map
options.throwOnFalseValidation	Optional	If pre or post-validator is false will throw an error	false
options.mapNullIfUndefined	Optional	If value is undefined it will cast to null	false
options.allErrors	Optional	Finish mapping logic before throwing the error on the function level. Will throw an array of all Errors.	false

Example

import ObjectMapper, { ObjectMap } from "@campfhir/object-mapper"

const data = {
    firstName: "scott",
    lastName: "eremia-roden"
    age: 18
}

const definition: ObjectMap<typeof data> = {
    firstName: {
        name: "fName",
        validator: {
            validate: (firstName) => {
                if (firstName === "scott") return true;
                else if (firstName === "not my name") return false
                else return false
            }
            message: "Name should be scott"
        },
        transformer: (firstName) => {
            return firstName.toUpperCase()
        }
    }
    lastName: false,
    age: "ageInYears"
}

let newData = ObjectMapper.map(data, definition);
console.log(newData.fName) // "SCOTT"
console.log(newData.ageInYears) // 18

Compare Objects

This method is used to compare one object to another.

Returns {status: string; errors: Error[]}

Arguments/Parameters	Required	Purpose	Default
lh	Required	The object to compare
rh	Required	The object to compare against
options.matchDataTypes	optional	Test that the keys in left hand object match and the data type is identical to the right hand object	false
options.exactValue	optional	Test that the keys and the values in left hand match exactly the data in right hand of the same key	false

Coalesce Array Object

Given an array of objects we group by like objects and reduce/coalesce to a single object. Returns an object. Throws if group by properties do not have identical elements.

Returns ReverseCoalesce<T,P>

Arguments/Parameters	Required	Purpose
arr	Required	The array of object to coalesce
groupBy	Required	Array of properties to group by

Add Parameters to SQL Request

Add array of parameters to mssql Request object

Returns void

Arguments/Parameters	Required	Purpose
params	Required	The array of SQL Parameters to add to the request
sp	Required	The request that the parameters should be added to

SQL Parameter Mapping

Given some data and mapping definition to generate an array of parameters, that can later be applied to a mssql Request object.

Returns SQLParameter[]

Arguments/Parameters	Required	Purpose	Default
input	Required	The data to map against
map	Required	A definition on what parameters to create and set
mapOptions.throwOnFalseValidation	Optional	If validator evaluates to false and this parameter is set to true the whole method will throw	false
mapOptions.allErrors	Optional	When true will iterate through the entire map before throwing error from method	false

SQL Table Parameter Mapping

Given some data and table definition will generate a table variable parameter to be used in a mssql Request object.

Returns mssql.Table

Arguments/Parameters	Required	Purpose
input	Required	The data used to map against
tableDefinition	Required	Array of column definitions
tableDefinition.name	Required	Name of the column
tableDefinition.option.type	Required	The SQL data type for the column