[#1348] initial groupBy implementation (#1364)

* initial groupBy implementation

1 files changed, 354 insertions, 0 deletions

diff --git a/mocha_test/groupBy.js b/mocha_test/groupBy.js
new file mode 100644
index 0000000..afb612b
--- /dev/null
+++ b/mocha_test/groupBy.js
@@ -0,0 +1,354 @@
+var async = require('../lib');
+var expect = require('chai').expect;
+var assert = require('assert');
+
+describe('groupBy', function() {
+    this.timeout(250);
+
+    function groupByIteratee(callOrder, val, next) {
+        setTimeout(function() {
+            callOrder.push(val);
+            next(null, val+1);
+        }, val * 25);
+    }
+
+    context('groupBy', function() {
+        it('basics', function(done) {
+            var callOrder = [];
+            async.groupBy([1, 3, 2], groupByIteratee.bind(this, callOrder), function(err, result) {
+                expect(err).to.eql(null);
+                expect(callOrder).to.eql([1, 2, 3]);
+                expect(result).to.eql({2: [1], 3: [2], 4: [3]});
+                done();
+            });
+        });
+
+        it('error', function(done) {
+            async.groupBy([1, 3, 2], function(val, next) {
+                if (val === 3) {
+                    return next(new Error('fail'));
+                }
+                next(null, val+1);
+            }, function(err, result) {
+                expect(err).to.not.eql(null);
+                expect(result).to.eql({2: [1]});
+                done();
+            });
+        });
+
+        it('original untouched', function(done) {
+            var obj = {a: 'b', b: 'c', c: 'd'};
+            async.groupBy(obj, function(val, next) {
+                next(null, val);
+            }, function(err, result) {
+                expect(obj).to.eql({a: 'b', b: 'c', c: 'd'});
+                expect(result).to.eql({b: ['b'], c: ['c'], d: ['d']});
+                done();
+            });
+        });
+
+        it('handles multiple matches', function(done) {
+            var callOrder = [];
+            async.groupBy([1, 3, 2, 2], groupByIteratee.bind(this, callOrder), function(err, result) {
+                expect(err).to.eql(null);
+                expect(callOrder).to.eql([1, 2, 2, 3]);
+                expect(result).to.eql({2: [1], 3: [2, 2], 4: [3]});
+                done();
+            });
+        });
+
+        it('handles objects', function(done) {
+            var obj = {a: 'b', b: 'c', c: 'd'};
+            var concurrency = {b: 3, c: 2, d: 1};
+            var running = 0;
+            async.groupBy(obj, function(val, next) {
+                running++;
+                async.setImmediate(function() {
+                    expect(running).to.equal(concurrency[val]);
+                    running--;
+                    next(null, val);
+                });
+            }, function(err, result) {
+                expect(running).to.equal(0);
+                expect(err).to.eql(null);
+                expect(result).to.eql({b: ['b'], c: ['c'], d: ['d']});
+                done();
+            });
+        });
+
+        it('handles undefined', function(done) {
+            async.groupBy(undefined, function(val, next) {
+                assert(false, 'iteratee should not be called');
+                next();
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({});
+                done();
+            });
+        });
+
+        it('handles empty object', function(done) {
+            async.groupBy({}, function(val, next) {
+                assert(false, 'iteratee should not be called');
+                next();
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({});
+                done();
+            });
+        });
+
+        it('main callback optional' , function(done) {
+            var arr = [1, 2, 3];
+            var runs = [];
+            async.groupBy(arr, function(val, next) {
+                runs.push(val);
+                var _done = (runs.length === arr.length);
+                async.setImmediate(function() {
+                    next(null);
+                    if (_done) {
+                        expect(runs).to.eql(arr);
+                        done();
+                    }
+                });
+            });
+        });
+
+        it('iteratee callback is only called once', function(done) {
+            async.groupBy([1, 2], function(item, callback) {
+                try {
+                    callback(item);
+                } catch (exception) {
+                    expect(function() {
+                        callback(exception);
+                    }).to.throw(/already called/);
+                    done();
+                }
+            }, function() {
+                throw new Error();
+            });
+        });
+
+        it('handles Map', function(done) {
+            if (typeof Map !== 'function') {
+                return done();
+            }
+
+            var map = new Map([
+                ['a', 'a'],
+                ['b', 'b'],
+                ['c', 'a']
+            ]);
+
+            async.groupBy(map, function(val, next) {
+                next(null, val[1]+1);
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({
+                    a1: [ ['a', 'a'], ['c', 'a']],
+                    b1: [ ['b', 'b'] ]
+                });
+                done();
+            });
+        });
+
+        it('handles sparse results', function(done) {
+            var arr = [1, 2, 3];
+            async.groupBy(arr, function(val, next) {
+                if (val === 1) {
+                    return next(null, val+1);
+                } else if (val === 2) {
+                    async.setImmediate(function() {
+                        return next(null, val+1);
+                    });
+                } else {
+                    return next('error');
+                }
+            }, function(err, result) {
+                expect(err).to.not.eql(null);
+                expect(result).to.eql({2: [1]});
+                async.setImmediate(done);
+            });
+        });
+    });
+
+    context('groupByLimit', function() {
+        var obj = {a: 'b', b: 'c', c: 'd'};
+        it('basics', function(done) {
+            var running = 0;
+            var concurrency = {'b': 2, 'c': 2, 'd': 1};
+            async.groupByLimit(obj, 2, function(val, next) {
+                running++;
+                async.setImmediate(function() {
+                    expect(running).to.equal(concurrency[val]);
+                    running--;
+                    next(null, val);
+                });
+            }, function(err, result) {
+                expect(running).to.equal(0);
+                expect(err).to.eql(null);
+                expect(result).to.eql({'b': ['b'], 'c': ['c'], 'd': ['d']})
+                done();
+            });
+        });
+
+        it('error', function(done) {
+            async.groupByLimit(obj, 1, function(val, next) {
+                if (val === 'c') {
+                    return next(new Error('fail'));
+                }
+                next(null, val);
+            }, function(err, result) {
+                expect(err).to.not.eql(null);
+                expect(result).to.eql({b: ['b']});
+                done();
+            });
+        });
+
+        it('handles empty object', function(done) {
+            async.groupByLimit({}, 2, function(val, next) {
+                assert(false, 'iteratee should not be called');
+                next();
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({});
+                done();
+            });
+        });
+
+        it('handles undefined', function(done) {
+            async.groupByLimit(undefined, 2, function(val, next) {
+                assert(false, 'iteratee should not be called');
+                next();
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({});
+                done();
+            });
+        });
+
+        it('limit exceeds size', function(done) {
+            var callOrder = [];
+            async.groupByLimit([3, 2, 2, 1], 10, groupByIteratee.bind(this, callOrder), function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({2: [1], 3: [2, 2], 4: [3]});
+                expect(callOrder).to.eql([1, 2, 2, 3]);
+                done();
+            });
+        });
+
+        it('limit equal size', function(done) {
+            var callOrder = [];
+            async.groupByLimit([3, 2, 2, 1], 4, groupByIteratee.bind(this, callOrder), function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({2: [1], 3: [2, 2], 4: [3]});
+                expect(callOrder).to.eql([1, 2, 2, 3]);
+                done();
+            });
+        });
+
+        it('zero limit', function(done) {
+            async.groupByLimit([3, 2, 2, 1], 0, function(val, next) {
+                assert(false, 'iteratee should not be called');
+                next();
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({});
+                done();
+            });
+        });
+
+        it('does not continue replenishing after error', function(done) {
+            var started = 0;
+            var arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+            var delay = 10;
+            var limit = 3;
+            var maxTime = 10 * arr.length;
+
+            async.groupByLimit(arr, limit, function(val, next) {
+                started++;
+                if (started === 3) {
+                    return next(new Error('fail'));
+                }
+
+                setTimeout(function() {
+                    next();
+                }, delay);
+            }, function(err, result) {
+                expect(err).to.not.eql(null);
+                expect(result).to.eql({});
+            });
+
+            setTimeout(function() {
+                expect(started).to.equal(3);
+                done();
+            }, maxTime);
+        });
+    });
+
+    context('groupBySeries', function() {
+        var obj = {a: 'b', b: 'c', c: 'd'};
+        it('basics', function(done) {
+            var running = 0;
+            var concurrency = {'b': 1, 'c': 1, 'd': 1};
+            async.groupBySeries(obj, function(val, next) {
+                running++;
+                async.setImmediate(function() {
+                    expect(running).to.equal(concurrency[val]);
+                    running--;
+                    next(null, val);
+                });
+            }, function(err, result) {
+                expect(running).to.equal(0);
+                expect(err).to.eql(null);
+                expect(result).to.eql({'b': ['b'], 'c': ['c'], 'd': ['d']});
+                done();
+            });
+        });
+
+        it('error', function(done) {
+            async.groupBySeries(obj, function(val, next) {
+                if (val === 'c') {
+                    return next(new Error('fail'));
+                }
+                next(null, val);
+            }, function(err, result) {
+                expect(err).to.not.eql(null);
+                expect(result).to.eql({b: ['b']});
+                done();
+            });
+        });
+
+        it('handles arrays', function(done) {
+            async.groupBySeries(['a', 'a', 'b'], function(val, next) {
+                next(null, val);
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({'a': ['a', 'a'], 'b': ['b']});
+                done();
+            });
+        });
+
+        it('handles empty object', function(done) {
+            async.groupByLimit({}, 2, function(val, next) {
+                assert(false, 'iteratee should not be called');
+                next();
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({});
+                done();
+            });
+        });
+
+        it('handles undefined', function(done) {
+            async.groupBySeries(undefined, function(val, next) {
+                assert(false, 'iteratee should not be called');
+                next();
+            }, function(err, result) {
+                expect(err).to.eql(null);
+                expect(result).to.eql({});
+                done();
+            });
+        });
+    });
+});