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Object filtering

Easily filter object by their properties - then get the filtered object back!

• Two types of filtering available: that will either 1) either exclude all of the matched properties or 2) include only the matched properties.
• Filter by a list of property names or regex filters (new feature).
• Recursive filtering option.
  • Recursive filtering will not inspect (filter within) arrays, sets, and maps.

Usage

• Install the package via npm install @jericirenej/object-filter.
  • You can also clone the repo and transpile the files manually (npm install, followed by npx tsc which will transpile to dist).
• Import the objectFilter function and pass it the appropriate configuration object.

import objectFilter from "object-filter";

/*
objectFilterConfig: {
  targetObject: Record<string,any>,
  filters?: string|string[],
  regexFilters?: string|RegExp|(string|RegExp)[], --- At least one of the filter groups needs to be valid. 
  filterType?: "exclude"|"include",               --- defaults to exclude.
  recursive?:boolean,                             --- defaults to false.

}
*/

const employeeInfo = {
  name: "John",
  surname: "Doe",
  personalInfo: {
    age: 30,
    sensitive1: "secret",
  },
  sensitive2: "secret",
};

const excludeSensitive = {
  targetObject: employeeInfo,
  filters: ["sensitive1", "sensitive2"],
  filterType: "exclude",
  recursive: true,
};

const cleanedEmployeeInfo = objectFilter(excludeSensitive);
// Will return
{
  name: "John",
  surname: "Doe",
  personalInfo: {
    age: 30,
  },
};

const includeSensitive = {
  targetObject: employeeInfo,
  filters: ["personalInfo", "sensitive1", "sensitive2"],
  filterType: "include",
  recursive: true,
}

const sensitiveEmployeeInfo = objectFilter(includeSensitive);

//Will return
{
  sensitive2: "secret",
  personalInfo: {
    sensitive1: "secret,
  }
}

// Combination of property name and regex filtering 
const mixedFilter = {
  targetObject: employeeInfo,
  filters: "personalInfo",
  regexFilters: /sensitive/,
  filterType: "include",
  recursive: true
} 
// If passed to objectFilter, will return the same result as for sensitiveEmployeeInfo.

Things to note

• Although the filterObject function creates a new object based on the old one, this is a shallow copy, not a clone". If you need to ensure immutability, use an appropriate library (lodash, immer), to clone the result.
• You need to supply at least one type of valid filter groups. If none of the supplied filter groups are valid, the original object will be returned.
• When using the include filterType together with the recursive option please note, that if filters target a nested property, their parent has to be provided as well, as it will be filtered out otherwise in the first filter step.
  • That makes the include option somewhat less practical than exclude.
• If you are working with TypeScript, make sure to type cast the returned object, as its type will be Record<string,any> by default.

Planned additional features

• Regex matching of properties. --> Implemented.
• Improved include filterType for recursive filterings (see limitation above).
• Tranpoline recursive calls.