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var R = require('../source');var eq = require('./shared/eq');
var byType = R.prop('type');var sumValues = function(acc, obj) {return acc + obj.val;};
var sumInput = [  {type: 'A', val: 10},  {type: 'B', val: 20},  {type: 'A', val: 30},  {type: 'A', val: 40},  {type: 'C', val: 50},  {type: 'B', val: 60}];
describe('reduceBy', function() {  it('splits the list into groups according to the grouping function', function() {    var grade = function(score) {      return (score < 65) ? 'F' : (score < 70) ? 'D' : (score < 80) ? 'C' : (score < 90) ? 'B' : 'A';    };    var students = [      {name: 'Abby', score: 84},      {name: 'Brad', score: 73},      {name: 'Chris', score: 89},      {name: 'Dianne', score: 99},      {name: 'Eddy', score: 58},      {name: 'Fred', score: 67},      {name: 'Gillian', score: 91},      {name: 'Hannah', score: 78},      {name: 'Irene', score: 85},      {name: 'Jack', score: 69}    ];    var byGrade = function(student) {return grade(student.score || 0);};    var collectNames = function(acc, student) {return acc.concat(student.name);};    eq(R.reduceBy(collectNames, [], byGrade, students), {      A: ['Dianne', 'Gillian'],      B: ['Abby', 'Chris', 'Irene'],      C: ['Brad', 'Hannah'],      D: ['Fred', 'Jack'],      F: ['Eddy']    });  });
  it('splits the list into mutation-free groups', function() {    var grade = function(score) {      return (score < 65) ? 'F' : (score < 70) ? 'D' : (score < 80) ? 'C' : (score < 90) ? 'B' : 'A';    };    var students = [      {name: 'Abby', score: 84},      {name: 'Brad', score: 73},      {name: 'Chris', score: 89},      {name: 'Dianne', score: 99},      {name: 'Eddy', score: 58},      {name: 'Fred', score: 67},      {name: 'Gillian', score: 91},      {name: 'Hannah', score: 78},      {name: 'Irene', score: 85},      {name: 'Jack', score: 69}    ];    var byGrade = function(student) {return grade(student.score || 0);};    var collectNames = function(acc, student) {      acc.push(student.name);      return acc;    };    eq(R.reduceBy(collectNames, [], byGrade, students), {      A: ['Dianne', 'Gillian'],      B: ['Abby', 'Chris', 'Irene'],      C: ['Brad', 'Hannah'],      D: ['Fred', 'Jack'],      F: ['Eddy']    });  });
  it('returns an empty object if given an empty array', function() {    eq(R.reduceBy(sumValues, 0, byType, []), {});  });
  it('can act as a transducer', function() {    var reduceToSumsBy = R.reduceBy(sumValues, 0);    var sumByType = reduceToSumsBy(byType);    eq(R.into(      {},      R.compose(sumByType, R.map(R.adjust(1, R.multiply(10)))),      sumInput    ), {A: 800, B: 800, C: 500});  });});