Golang rivers.NewContext函数代码示例

func TestBatchCacheLoader(t *testing.T) {
	Convey("Given I have an empty batch of size 2", t, func() {
		batch := &appx.MemcacheLoadBatch{Size: 2}
		So(batch.Empty(), ShouldBeTrue)
		So(batch.Full(), ShouldBeFalse)

		Convey("When I add an entity to the batch", func() {
			batch.Add(NewUserWithFakeKey(User{Name: "borges"}))

			Convey("Then the batch is no longer empty", func() {
				So(batch.Empty(), ShouldBeFalse)

				Convey("And it is not yet full", func() {
					So(batch.Full(), ShouldBeFalse)
				})
			})
		})

		Convey("When I add enough entities", func() {
			batch.Add(NewUserWithFakeKey(User{Name: "borges"}))
			batch.Add(NewUserWithFakeKey(User{Name: "diego"}))

			Convey("Then the batch is full", func() {
				So(batch.Full(), ShouldBeTrue)
			})
		})

		Convey("When I commit the batch", func() {
			in, out := stream.New(1)

			entity1 := NewUserWithFakeKey(User{
				Name: "entity1",
				SSN:  "123123",
			})

			entity2 := NewUserWithFakeKey(User{
				Name: "entity2",
				SSN:  "321321",
			})

			batch.Add(entity1)
			batch.Add(entity2)
			batch.Commit(stream.NewEmitter(rivers.NewContext(), out))
			close(out)

			Convey("Then a copy of the batch is sent to the output stream", func() {
				committedBatch := (<-in).(*appx.MemcacheLoadBatch)
				So(committedBatch.Size, ShouldEqual, 2)
				So(committedBatch.Keys[0], ShouldEqual, entity1.CacheID())
				So(committedBatch.Keys[1], ShouldEqual, entity2.CacheID())
				So(committedBatch.Items[entity1.CacheID()], ShouldResemble, &appx.CachedEntity{Entity: entity1})
				So(committedBatch.Items[entity2.CacheID()], ShouldResemble, &appx.CachedEntity{Entity: entity2})

				Convey("And the batch is now empty", func() {
					So(batch.Empty(), ShouldBeTrue)
				})
			})
		})
	})
}

func TestFromSlice(t *testing.T) {
	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And I have a slice producer", func() {
			numbers := []int{1, 2, 3}
			producer := producers.FromSlice(numbers)

			Convey("When I produce data", func() {
				producer.Attach(context)
				readable := producer.Produce()

				Convey("Then I can read the produced data from the stream", func() {
					So(readable.ReadAll(), ShouldResemble, []stream.T{1, 2, 3})
				})
			})
		})

		Convey("And I have a data producer", func() {
			producer := producers.FromData(1, 2, 3)

			Convey("When I produce data", func() {
				producer.Attach(context)
				readable := producer.Produce()

				Convey("Then I can read the produced data from the stream", func() {
					So(readable.ReadAll(), ShouldResemble, []stream.T{1, 2, 3})
				})
			})
		})
	})
}

func TestLoadBatchFromDatastore(t *testing.T) {
	gaeCtx, _ := aetest.NewContext(nil)
	defer gaeCtx.Close()

	Convey("Given I have a load batch from datastore transformer", t, func() {
		riversCtx := rivers.NewContext()
		loadBatchProcessor := appx.NewStep(riversCtx).LoadBatchFromDatastore(gaeCtx)

		Convey("And I have a few entities in datastore", func() {
			user1 := NewUser(User{
				Name:  "Borges",
				Email: "[email protected]",
				SSN:   "123123123",
			})

			user2 := NewUser(User{
				Name:  "Borges",
				Email: "[email protected]",
				SSN:   "123123123",
			})

			err := appx.NewKeyResolver(gaeCtx).Resolve(user1)
			So(err, ShouldBeNil)
			err = appx.NewKeyResolver(gaeCtx).Resolve(user2)
			So(err, ShouldBeNil)

			_, err = datastore.Put(gaeCtx, user1.Key(), user1)
			So(err, ShouldBeNil)
			_, err = datastore.Put(gaeCtx, user2.Key(), user2)
			So(err, ShouldBeNil)

			Convey("When I transform the incoming batch", func() {
				userFromDatastore1 := NewUser(User{Name: user1.Name})
				userFromDatastore2 := NewUser(User{Name: user2.Name})
				appx.NewKeyResolver(gaeCtx).Resolve(userFromDatastore1)
				appx.NewKeyResolver(gaeCtx).Resolve(userFromDatastore2)

				batch := &appx.DatastoreBatch{
					Size: 2,
					Keys: []*datastore.Key{
						userFromDatastore1.Key(),
						userFromDatastore2.Key(),
					},
					Items: []appx.Entity{
						userFromDatastore1,
						userFromDatastore2,
					},
				}

				loadBatchProcessor(batch)

				Convey("And entities are loaded from datastore", func() {
					So(userFromDatastore1, ShouldResemble, user1)
					So(userFromDatastore2, ShouldResemble, user2)
				})
			})
		})
	})
}

func TestEach(t *testing.T) {
	collect := func(items *[]stream.T) stream.EachFn {
		return func(data stream.T) {
			*items = append(*items, data)
		}
	}

	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(2)
			out <- 1
			out <- 2
			close(out)

			Convey("When I apply the transformer to the stream", func() {
				var items []stream.T
				transformer := transformers.Each(collect(&items))
				transformer.Attach(context)
				next := transformer.Transform(in)

				Convey("Then all items are sent to the next stage", func() {
					So(next.ReadAll(), ShouldResemble, []stream.T{1, 2})

					Convey("And all items are transformed", func() {
						So(items, ShouldResemble, []stream.T{1, 2})
					})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					var items []stream.T
					transformer := transformers.Each(collect(&items))
					transformer.Attach(context)
					next := transformer.Transform(in)

					Convey("Then no item is sent to the next stage", func() {
						So(next.ReadAll(), ShouldBeEmpty)

						Convey("And no item is transformed", func() {
							So(items, ShouldBeEmpty)
						})
					})
				})
			})
		})
	})
}

func TestZipperBy(t *testing.T) {
	adder := func(a, b stream.T) stream.T {
		return a.(int) + b.(int)
	}

	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in1, out1 := stream.New(2)
			out1 <- 1
			out1 <- 2
			close(out1)

			in2, out2 := stream.New(4)
			out2 <- 3
			out2 <- 4
			out2 <- 5
			out2 <- 6
			close(out2)

			Convey("When I apply the combiner to the streams", func() {
				combiner := combiners.ZipBy(adder)
				combiner.Attach(context)
				combined := combiner.Combine(in1, in2)

				Convey("Then a transformed stream is returned", func() {
					So(combined.ReadAll(), ShouldResemble, []stream.T{4, 6, 5, 6})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					combiner := combiners.ZipBy(adder)
					combiner.Attach(context)
					combined := combiner.Combine(in1, in2)

					Convey("Then no item is sent to the next stage", func() {
						So(combined.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}

func TestBatcher(t *testing.T) {
	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(3)
			out <- 1
			out <- 2
			out <- 3
			close(out)

			Convey("When I apply the batch transformer to the stream", func() {
				transformer := transformers.Batch(2)
				transformer.Attach(context)
				next := transformer.Transform(in)

				Convey("Then a transformed stream is returned", func() {
					So(next.ReadAll(), ShouldResemble, []stream.T{[]stream.T{1, 2}, []stream.T{3}})
				})
			})

			Convey("When I apply the batch by transformer to the stream", func() {
				transformer := transformers.BatchBy(&batch{size: 1})
				transformer.Attach(context)
				next := transformer.Transform(in)

				Convey("Then a transformed stream is returned", func() {
					So(next.ReadAll(), ShouldResemble, []stream.T{[]stream.T{1}, []stream.T{2}, []stream.T{3}})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					transformer := transformers.Flatten()
					transformer.Attach(context)
					next := transformer.Transform(in)

					Convey("Then no item is sent to the next stage", func() {
						So(next.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}

func TestFifo(t *testing.T) {
	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in1, out1 := stream.New(2)
			out1 <- 1
			out1 <- 2
			close(out1)

			in2, out2 := stream.New(2)
			out2 <- 3
			out2 <- 4
			close(out2)

			Convey("When I apply the combiner to the streams", func() {
				combiner := combiners.FIFO()
				combiner.Attach(context)
				combined := combiner.Combine(in1, in2)

				Convey("Then a transformed stream is returned", func() {
					items := combined.ReadAll()
					So(items, should.Contain, 1)
					So(items, should.Contain, 2)
					So(items, should.Contain, 3)
					So(items, should.Contain, 4)
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					combiner := combiners.Zip()
					combiner.Attach(context)
					combined := combiner.Combine(in1, in2)

					Convey("Then no item is sent to the next stage", func() {
						So(combined.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}

func TestFromRange(t *testing.T) {
	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And I have a range producer", func() {
			producer := producers.FromRange(1, 3)
			producer.Attach(context)

			Convey("When I produce data", func() {
				readable := producer.Produce()

				Convey("Then I can read the produced data from the stream", func() {
					So(readable.ReadAll(), ShouldResemble, []stream.T{1, 2, 3})
				})
			})
		})
	})
}

func TestProcessor(t *testing.T) {
	evensFilter := func(d stream.T, emitter stream.Emitter) {
		if d.(int)%2 == 0 {
			emitter.Emit(d)
		}
	}

	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(2)
			out <- 1
			out <- 2
			close(out)

			Convey("When I apply the transformer to the stream", func() {
				transformer := transformers.OnData(evensFilter)
				transformer.Attach(context)
				transformed := transformer.Transform(in)

				Convey("Then a transformed stream is returned", func() {
					So(transformed.ReadAll(), ShouldResemble, []stream.T{2})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					transformer := transformers.OnData(evensFilter)
					transformer.Attach(context)
					next := transformer.Transform(in)

					Convey("Then no item is sent to the next stage", func() {
						So(next.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}

func TestFromFileByLine(t *testing.T) {
	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And I have a file with some data", func() {
			ioutil.WriteFile("/tmp/from_file_by_line", []byte("Hello\nthere\nfolks!"), 0644)
			file, _ := os.Open("/tmp/from_file_by_line")

			Convey("When I produce data from the file", func() {
				producer := producers.FromFile(file).ByLine()
				producer.Attach(context)
				readable := producer.Produce()

				Convey("Then I can read the produced data from the stream", func() {
					So(readable.ReadAll(), ShouldResemble, []stream.T{"Hello", "there", "folks!"})
				})
			})
		})
	})
}

func TestReducer(t *testing.T) {
	sum := func(acc, next stream.T) stream.T { return acc.(int) + next.(int) }

	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(3)
			out <- 1
			out <- 2
			out <- 3
			close(out)

			Convey("When I apply a mapper transformer to the stream", func() {
				transformer := transformers.Reduce(0, sum)
				transformer.Attach(context)
				next := transformer.Transform(in)

				Convey("Then a transformed stream is returned", func() {
					So(next.ReadAll(), ShouldResemble, []stream.T{6})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					transformer := transformers.Reduce(0, sum)
					transformer.Attach(context)
					next := transformer.Transform(in)

					Convey("Then no item is sent to the next stage", func() {
						So(next.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}

func TestFindBy(t *testing.T) {
	evens := func(d stream.T) bool { return d.(int)%2 == 0 }

	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(3)
			out <- 1
			out <- 2
			out <- 4
			close(out)

			Convey("When I apply the transformer to the stream", func() {
				transformer := transformers.FindBy(evens)
				transformer.Attach(context)
				next := transformer.Transform(in)

				Convey("Then a transformed stream is returned", func() {
					So(next.ReadAll(), ShouldResemble, []stream.T{2})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					transformer := transformers.FindBy(evens)
					transformer.Attach(context)
					next := transformer.Transform(in)

					Convey("Then no item is sent to the next stage", func() {
						So(next.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}

func TestItemsCollector(t *testing.T) {
	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(2)
			out <- 1
			out <- 2
			close(out)

			Convey("When I apply the collector consumer", func() {
				var data []stream.T
				consumer := consumers.ItemsCollector(&data)
				consumer.Attach(context)
				consumer.Consume(in)

				Convey("Then data is collected out of the stream", func() {
					So(data, ShouldResemble, []stream.T{1, 2})

					data, opened := <-in
					So(data, ShouldBeNil)
					So(opened, ShouldBeFalse)
				})
			})

			Convey("When I apply the collector consuming data into a non slice pointer", func() {
				var data []stream.T
				collect := func() {
					consumers.ItemsCollector(data)
				}

				Convey("Then it panics", func() {
					So(collect, ShouldPanicWith, consumers.ErrNoSuchSlicePointer)
				})
			})
		})
	})
}

func TestMapper(t *testing.T) {
	inc := func(d stream.T) stream.T { return d.(int) + 1 }

	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(2)
			out <- 1
			out <- 2
			close(out)

			Convey("When I apply a mapper transformer to the stream", func() {
				transformer := transformers.Map(inc)
				transformer.Attach(context)
				transformed := transformer.Transform(in)

				Convey("Then a transformed stream is returned", func() {
					So(transformed.ReadAll(), ShouldResemble, []stream.T{2, 3})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					transformer := transformers.Map(inc)
					transformer.Attach(context)
					next := transformer.Transform(in)

					Convey("Then no item is sent to the next stage", func() {
						So(next.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}

func TestTakeN(t *testing.T) {
	Convey("Given I have a context", t, func() {
		context := rivers.NewContext()

		Convey("And a stream of data", func() {
			in, out := stream.New(3)
			out <- 1
			out <- 2
			out <- 3
			close(out)

			Convey("When I apply the transformer to the stream", func() {
				transformer := transformers.TakeFirst(2)
				transformer.Attach(context)
				transformed := transformer.Transform(in)

				Convey("Then a transformed stream is returned", func() {
					So(transformed.ReadAll(), ShouldResemble, []stream.T{1, 2})
				})
			})

			Convey("When I close the context", func() {
				context.Close(stream.Done)

				Convey("And I apply the transformer to the stream", func() {
					transformer := transformers.TakeFirst(1)
					transformer.Attach(context)
					next := transformer.Transform(in)

					Convey("Then no item is sent to the next stage", func() {
						So(next.ReadAll(), ShouldBeEmpty)
					})
				})
			})
		})
	})
}