eslint-plugin-angular/rules/di-unused.js

ESLint rules for AngularJS projects

/**
 * disallow unused DI parameters
 *
 * Unused dependencies should not be injected.
 *
 * @version 0.8.0
 * @category bestPractice
 */
'use strict';

var angularRule = require('./utils/angular-rule');


module.exports = angularRule(function(context) {
    // Keeps track of visited scopes in the collectAngularScopes function to prevent infinite recursion on circular references.
    var visitedScopes = [];

    // This collects the variable scopes for the injectible functions which have been collected.
    function collectAngularScopes(scope) {
        if (visitedScopes.indexOf(scope) === -1) {
            visitedScopes.push(scope);
            scope.childScopes.forEach(function(child) {
                collectAngularScopes(child);
            });
        }
    }

    function reportUnusedVariables(callee, fn) {
        if (!fn) {
            return;
        }
        visitedScopes.some(function(scope) {
            if (scope.block !== fn) {
                return;
            }
            scope.variables.forEach(function(variable) {
                if (variable.name === 'arguments') {
                    return;
                }
                if (fn.params.indexOf(variable.identifiers[0]) === -1) {
                    return;
                }
                if (variable.references.length === 0) {
                    context.report(fn, 'Unused injected value {{name}}', variable);
                }
            });
            return true;
        });
    }

    return {
        'angular:animation': reportUnusedVariables,
        'angular:config': reportUnusedVariables,
        'angular:controller': reportUnusedVariables,
        'angular:directive': reportUnusedVariables,
        'angular:factory': reportUnusedVariables,
        'angular:filter': reportUnusedVariables,
        'angular:inject': reportUnusedVariables,
        'angular:run': reportUnusedVariables,
        'angular:service': reportUnusedVariables,
        'angular:provider': function(callee, providerFn, $get) {
            reportUnusedVariables(null, providerFn);
            reportUnusedVariables(null, $get);
        },

        // Actually find and report unused injected variables.
        'Program:exit': function() {
            var globalScope = context.getScope();
            collectAngularScopes(globalScope);
        }
    };
});