archunit/dist/src/metrics/calculation/lcom.d.ts

ArchUnit TypeScript is an architecture testing library, to specify and assert architecture rules in your TypeScript app

import { ClassInfo, Metric } from '../extraction/interface';
/**
 * LCOM (Lack of Cohesion of Methods) metrics interface
 */
export interface LCOMMetric extends Metric {
    name: string;
    calculate(classInfo: ClassInfo): number;
    description: string;
}
/**
 * LCOM96a (Lack of Cohesion of Methods, Handerson et al., 1996)
 *
 * Formula: LCOM96a = (1/(1-m)) * ((1/a) * Σ(μ(A)) - m) for all attributes A
 *
 * Where:
 * - a is the number of attributes (fields) in the class
 * - m is the number of attributes (fields) in the class
 * - μ(A) is the number of methods that access an attribute (field) A
 * - The formula measures how methods are connected through attributes
 *
 * Returns a value >= 0:
 * - 0: perfect cohesion
 * - Higher values: increasing lack of cohesion
 */
export declare class LCOM96a implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}
/**
 * LCOM96b (Lack of Cohesion of Methods, Handerson et al., 1996)
 *
 * Formula: LCOM96b = (1/a) * Σ((1/m) * (m - μ(A))) for all attributes A
 *
 * Where:
 * - m is the number of methods in the class
 * - a is the number of attributes (fields) in the class
 * - μ(A) is the number of methods that access an attribute (field) A
 * - The formula measures how methods are connected through attributes
 *
 * Returns a value between 0 and 1:
 * - 0: perfect cohesion (all methods access all attributes)
 * - 1: complete lack of cohesion (each method accesses its own attribute)
 */
export declare class LCOM96b implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}
/**
 * LCOM1 (Chidamber & Kemerer, 1991)
 *
 * Formula: LCOM1 = |P| - |Q|, where P > Q, otherwise 0
 *
 * Where:
 * - P is the set of method pairs that do not share instance variables
 * - Q is the set of method pairs that share at least one instance variable
 * - If P <= Q, then LCOM1 = 0
 *
 * Returns a value >= 0:
 * - 0: good cohesion
 * - Higher values: lack of cohesion
 */
export declare class LCOM1 implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}
/**
 * LCOM2 (Chidamber & Kemerer, 1994 - revised)
 *
 * Formula: LCOM2 = 1 - (Σ(MF) / (M * F))
 *
 * Where:
 * - M is the number of methods in the class
 * - F is the number of fields in the class
 * - MF is the number of methods that access each field
 * - Σ(MF) is the sum of MF over all fields
 *
 * Returns a value between 0 and 1:
 * - 0: perfect cohesion (all methods access all fields)
 * - 1: no cohesion (no method accesses any field)
 */
export declare class LCOM2 implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}
/**
 * LCOM3 (Li & Henry, 1993)
 *
 * Formula: LCOM3 = (M - Σ(MF)/F) / (M - 1)
 *
 * Where:
 * - M is the number of methods in the class
 * - F is the number of fields in the class
 * - MF is the number of methods that access each field
 * - Σ(MF) is the sum of MF over all fields
 *
 * Returns a value between 0 and 1:
 * - 0: perfect cohesion
 * - 1: lack of cohesion
 */
export declare class LCOM3 implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}
/**
 * LCOM4 (Hitz & Montazeri, 1995)
 *
 * Formula: LCOM4 = number of connected components in the method-field graph
 *
 * Where:
 * - A connected component is a maximal set of methods connected through shared fields
 * - Methods are connected if they access the same field or are transitively connected
 *
 * Returns a value >= 1:
 * - 1: perfect cohesion (all methods are connected)
 * - Higher values: increasing lack of cohesion
 */
export declare class LCOM4 implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}
/**
 * LCOM5 (Henderson-Sellers, 1996)
 *
 * Formula: LCOM5 = (a - μΣ(mA)) / (a - μ)
 *
 * Where:
 * - a is the number of attributes (fields)
 * - μ is the number of methods
 * - mA is the number of methods accessing attribute A
 * - Σ(mA) is the sum over all attributes
 *
 * Returns a value between 0 and 1:
 * - 0: perfect cohesion
 * - 1: lack of cohesion
 */
export declare class LCOM5 implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}
/**
 * LCOM* (Fernandez & Pena, 2006) - also known as LCOM-star
 *
 * Formula: LCOM* = (number of method pairs without shared attributes) / (total method pairs)
 *
 * Where:
 * - Method pairs are counted once (not twice)
 * - Shared attributes means both methods access at least one common field
 *
 * Returns a value between 0 and 1:
 * - 0: perfect cohesion (all method pairs share attributes)
 * - 1: no cohesion (no method pairs share attributes)
 */
export declare class LCOMStar implements LCOMMetric {
    name: string;
    description: string;
    calculate(classInfo: ClassInfo): number;
}