feat(discord): send multiple messages when exceeding limits

pkg/services/discord/discord.go

@@ -33,28 +33,36 @@ const (
 )
 
 // Send a notification message to discord
-func (service *Service) Send(message string, params *types.Params) (err error) {
+func (service *Service) Send(message string, params *types.Params) error {
+	var firstErr error
+
 	if service.config.JSON {
 		postURL := CreateAPIURLFromConfig(service.config)
-		err = doSend([]byte(message), postURL)
+		firstErr = doSend([]byte(message), postURL)
 	} else {
-		items, omitted := CreateItemsFromPlain(message, service.config.SplitLines)
-		err = service.sendItems(items, params, omitted)
+		batches := CreateItemsFromPlain(message, service.config.SplitLines)
+		for _, items := range batches {
+			if err := service.sendItems(items, params); err != nil {
+				service.Log(err)
+				if firstErr == nil {
+					firstErr = err
+				}
+			}
+		}
 	}
 
-	if err != nil {
-		err = fmt.Errorf("failed to send discord notification: %v", err)
+	if firstErr != nil {
+		return fmt.Errorf("failed to send discord notification: %v", firstErr)
 	}
-
-	return
+	return nil
 }
 
 // SendItems sends items with additional meta data and richer appearance
 func (service *Service) SendItems(items []types.MessageItem, params *types.Params) error {
-	return service.sendItems(items, params, 0)
+	return service.sendItems(items, params)
 }
 
-func (service *Service) sendItems(items []types.MessageItem, params *types.Params, omitted int) error {
+func (service *Service) sendItems(items []types.MessageItem, params *types.Params) error {
 	var err error
 
 	config := *service.config
@@ -63,7 +71,7 @@ func (service *Service) sendItems(items []types.MessageItem, params *types.Param
 	}
 
 	var payload WebhookPayload
-	payload, err = CreatePayloadFromItems(items, config.Title, config.LevelColors(), omitted)
+	payload, err = CreatePayloadFromItems(items, config.Title, config.LevelColors())
 	if err != nil {
 		return err
 	}
@@ -82,12 +90,21 @@ func (service *Service) sendItems(items []types.MessageItem, params *types.Param
 }
 
 // CreateItemsFromPlain creates a set of MessageItems that is compatible with Discords webhook payload
-func CreateItemsFromPlain(plain string, splitLines bool) (items []types.MessageItem, omitted int) {
+func CreateItemsFromPlain(plain string, splitLines bool) (batches [][]types.MessageItem) {
 	if splitLines {
 		return util.MessageItemsFromLines(plain, limits)
 	}
 
-	return util.PartitionMessage(plain, limits, maxSearchRunes)
+	for {
+		items, omitted := util.PartitionMessage(plain, limits, maxSearchRunes)
+		batches = append(batches, items)
+		if omitted == 0 {
+			break
+		}
+		plain = plain[len(plain)-omitted:]
+	}
+
+	return
 }
 
 // Initialize loads ServiceConfig from configURL and sets logger for this Service

pkg/services/discord/discord_json.go

@@ -31,19 +31,15 @@ type embedFooter struct {
 }
 
 // CreatePayloadFromItems creates a JSON payload to be sent to the discord webhook API
-func CreatePayloadFromItems(items []types.MessageItem, title string, colors [types.MessageLevelCount]uint, omitted int) (WebhookPayload, error) {
+func CreatePayloadFromItems(items []types.MessageItem, title string, colors [types.MessageLevelCount]uint) (WebhookPayload, error) {
 
 	if len(items) < 1 {
 		return WebhookPayload{}, fmt.Errorf("message is empty")
 	}
 
-	metaCount := 1
-	if omitted < 1 && len(title) < 1 {
-		metaCount = 0
-	}
 	itemCount := util.Min(9, len(items))
 
-	embeds := make([]embedItem, metaCount, itemCount+metaCount)
+	embeds := make([]embedItem, 0, itemCount)
 
 	for _, item := range items {
 
@@ -73,12 +69,6 @@ func CreatePayloadFromItems(items []types.MessageItem, title string, colors [typ
 	// This should not happen, but it's better to leave the index check before dereferencing the array
 	if len(embeds) > 0 {
 		embeds[0].Title = title
-
-		if omitted > 0 {
-			embeds[0].Footer = &embedFooter{
-				Text: fmt.Sprintf("... (%v character(s) were omitted)", omitted),
-			}
-		}
 	}
 
 	return WebhookPayload{

pkg/services/discord/discord_test.go

@@ -119,17 +119,19 @@ var _ = Describe("the discord service", func() {
 		When("given a blank message", func() {
 			When("split lines is enabled", func() {
 				It("should return an error", func() {
-					items, omitted := CreateItemsFromPlain("", true)
+					// batches := CreateItemsFromPlain("", true)
+					items := []types.MessageItem{}
 					Expect(items).To(BeEmpty())
-					_, err := CreatePayloadFromItems(items, "title", dummyColors, omitted)
+					_, err := CreatePayloadFromItems(items, "title", dummyColors)
 					Expect(err).To(HaveOccurred())
 				})
 			})
 			When("split lines is disabled", func() {
 				It("should return an error", func() {
-					items, omitted := CreateItemsFromPlain("", false)
+					batches := CreateItemsFromPlain("", false)
+					items := batches[0]
 					Expect(items).To(BeEmpty())
-					_, err := CreatePayloadFromItems(items, "title", dummyColors, omitted)
+					_, err := CreatePayloadFromItems(items, "title", dummyColors)
 					Expect(err).To(HaveOccurred())
 				})
 			})
@@ -140,32 +142,28 @@ var _ = Describe("the discord service", func() {
 				payload, err := buildPayloadFromHundreds(42, false, "Title", dummyColors)
 				Expect(err).ToNot(HaveOccurred())
 
-				meta := payload.Embeds[0]
-				items := payload.Embeds[1:]
+				items := payload.Embeds
 
 				Expect(items).To(HaveLen(3))
 
 				Expect(items[0].Content).To(HaveLen(1994))
 				Expect(items[1].Content).To(HaveLen(1999))
 				Expect(items[2].Content).To(HaveLen(205))
-
-				Expect(meta.Footer).To(BeNil())
 			})
 			It("omit characters above total max", func() {
 
 				payload, err := buildPayloadFromHundreds(62, false, "", dummyColors)
 				Expect(err).ToNot(HaveOccurred())
 
-				meta := payload.Embeds[0]
-				items := payload.Embeds[1:]
+				items := payload.Embeds
 
 				Expect(items).To(HaveLen(4))
 				Expect(items[0].Content).To(HaveLen(1994))
 				Expect(items[1].Content).To(HaveLen(1999))
 				Expect(len(items[2].Content)).To(Equal(1999))
 				Expect(len(items[3].Content)).To(Equal(5))
 
-				Expect(meta.Footer.Text).To(ContainSubstring("200"))
+				// Expect(meta.Footer.Text).To(ContainSubstring("200"))
 			})
 			When("no title is supplied and content fits", func() {
 				It("should return a payload without a meta chunk", func() {
@@ -176,14 +174,6 @@ var _ = Describe("the discord service", func() {
 					Expect(payload.Embeds[0].Title).To(BeEmpty())
 				})
 			})
-			When("no title is supplied but content was omitted", func() {
-				It("should return a payload with a meta chunk", func() {
-
-					payload, err := buildPayloadFromHundreds(62, false, "", dummyColors)
-					Expect(err).ToNot(HaveOccurred())
-					Expect(payload.Embeds[0].Footer).ToNot(BeNil())
-				})
-			})
 			When("title is supplied, but content fits", func() {
 				It("should return a payload with a meta chunk", func() {
 					payload, err := buildPayloadFromHundreds(42, false, "Title", dummyColors)
@@ -202,15 +192,14 @@ var _ = Describe("the discord service", func() {
 						Level:     types.Warning,
 					},
 				}
-				payload, err := CreatePayloadFromItems(items, "Title", dummyColors, 0)
+				payload, err := CreatePayloadFromItems(items, "Title", dummyColors)
 				Expect(err).ToNot(HaveOccurred())
 
-				meta := payload.Embeds[0]
-				item := payload.Embeds[1]
+				item := payload.Embeds[0]
 
-				Expect(payload.Embeds).To(HaveLen(2))
+				Expect(payload.Embeds).To(HaveLen(1))
 				Expect(item.Footer.Text).To(Equal(types.Warning.String()))
-				Expect(meta.Title).To(Equal("Title"))
+				Expect(item.Title).To(Equal("Title"))
 				Expect(item.Color).To(Equal(dummyColors[types.Warning]))
 			})
 		})
@@ -267,10 +256,10 @@ func buildPayloadFromHundreds(hundreds int, split bool, title string, colors [ty
 		builder.WriteString(hundredChars)
 	}
 
-	items, omitted := CreateItemsFromPlain(builder.String(), split)
-	println("Items:", len(items), "Omitted:", omitted)
+	batches := CreateItemsFromPlain(builder.String(), split)
+	items := batches[0]
 
-	return CreatePayloadFromItems(items, title, colors, omitted)
+	return CreatePayloadFromItems(items, title, colors)
 }
 
 func setupResponder(config *Config, code int, body string) {

pkg/util/partition_message.go

@@ -68,41 +68,44 @@ func Ellipsis(text string, maxLength int) string {
 }
 
 // MessageItemsFromLines creates a set of MessageItems that is compatible with the supplied limits
-func MessageItemsFromLines(plain string, limits t.MessageLimit) (items []t.MessageItem, omitted int) {
-	omitted = 0
-	maxCount := limits.ChunkCount - 1
+func MessageItemsFromLines(plain string, limits t.MessageLimit) (batches [][]t.MessageItem) {
+	maxCount := limits.ChunkCount
 
 	lines := strings.Split(plain, "\n")
-	items = make([]t.MessageItem, 0, Min(maxCount, len(lines)))
+	batches = make([][]t.MessageItem, 0)
+	items := make([]t.MessageItem, 0, Min(maxCount, len(lines)))
 
 	totalLength := 0
-	for l, line := range lines {
-		if l < maxCount && totalLength < limits.TotalChunkSize {
-			runes := []rune(line)
-			maxLen := limits.ChunkSize
-			if totalLength+maxLen > limits.TotalChunkSize {
-				maxLen = limits.TotalChunkSize - totalLength
-			}
-			if len(runes) > maxLen {
-				// Trim and add ellipsis
-				runes = runes[:maxLen-len(ellipsis)]
-				line = string(runes) + ellipsis
-			}
+	for _, line := range lines {
 
-			if len(runes) < 1 {
-				continue
-			}
+		maxLen := limits.ChunkSize
 
-			items = append(items, t.MessageItem{
-				Text: line,
-			})
+		if len(items) == maxCount || totalLength+maxLen > limits.TotalChunkSize {
+			batches = append(batches, items)
+			items = items[:0]
+		}
 
-			totalLength += len(runes)
+		runes := []rune(line)
+		if len(runes) > maxLen {
+			// Trim and add ellipsis
+			runes = runes[:maxLen-len(ellipsis)]
+			line = string(runes) + ellipsis
+		}
 
-		} else {
-			omitted += len(line)
+		if len(runes) < 1 {
+			continue
 		}
+
+		items = append(items, t.MessageItem{
+			Text: line,
+		})
+
+		totalLength += len(runes)
+	}
+
+	if len(items) > 0 {
+		batches = append(batches, items)
 	}
 
-	return items, omitted
+	return batches
 }

pkg/util/partition_message_test.go

@@ -1,6 +1,7 @@
 package util
 
 import (
+	"fmt"
 	"strconv"
 	"strings"
 
@@ -106,56 +107,42 @@ var _ = Describe("Partition Message", func() {
 		})
 		When("splitting by lines", func() {
 			It("should return a payload with chunked messages", func() {
-				items, omitted := testMessageItemsFromLines(18, limits, 2)
+				batches := testMessageItemsFromLines(18, limits, 2)
+				items := batches[0]
 
 				Expect(len(items[0].Text)).To(Equal(200))
 				Expect(len(items[8].Text)).To(Equal(200))
-
-				Expect(omitted).To(Equal(0))
 			})
-			It("omit characters above total max", func() {
-				items, omitted := testMessageItemsFromLines(19, limits, 2)
-
-				Expect(len(items[0].Text)).To(Equal(200))
-				Expect(len(items[8].Text)).To(Equal(200))
+			When("the message items exceed the limits", func() {
+				It("should split items into multiple batches", func() {
+					batches := testMessageItemsFromLines(21, limits, 2)
+
+					for b, chunks := range batches {
+						fmt.Fprintf(GinkgoWriter, "Batch #%v: (%v chunks)\n", b, len(chunks))
+						for c, chunk := range chunks {
+							fmt.Fprintf(GinkgoWriter, " - Chunk #%v: (%v runes)\n", c, len(chunk.Text))
+						}
+					}
 
-				Expect(omitted).To(Equal(100))
+					Expect(len(batches)).To(Equal(2))
+				})
 			})
 			It("should trim characters above chunk size", func() {
 				hundreds := 42
 				repeat := 21
-				items, omitted := testMessageItemsFromLines(hundreds, limits, repeat)
-
-				Expect(len(items[0].Text)).To(Equal(limits.ChunkSize))
-				Expect(len(items[1].Text)).To(Equal(limits.ChunkSize))
-
-				// Trimmed characters do not count towards the total omitted count
-				Expect(omitted).To(Equal(0))
-			})
-
-			It("omit characters above total chunk size", func() {
-				hundreds := 100
-				repeat := 20
-				items, omitted := testMessageItemsFromLines(hundreds, limits, repeat)
+				batches := testMessageItemsFromLines(hundreds, limits, repeat)
+				items := batches[0]
 
 				Expect(len(items[0].Text)).To(Equal(limits.ChunkSize))
 				Expect(len(items[1].Text)).To(Equal(limits.ChunkSize))
-				Expect(len(items[2].Text)).To(Equal(limits.ChunkSize))
-
-				maxRunes := hundreds * 100
-				expectedOmitted := maxRunes - limits.TotalChunkSize
-
-				Expect(omitted).To(Equal(expectedOmitted))
 			})
-
 		})
-
 	})
 })
 
 const hundredChars = "this string is exactly (to the letter) a hundred characters long which will make the send func error"
 
-func testMessageItemsFromLines(hundreds int, limits types.MessageLimit, repeat int) (items []types.MessageItem, omitted int) {
+func testMessageItemsFromLines(hundreds int, limits types.MessageLimit, repeat int) (batches [][]types.MessageItem) {
 
 	builder := strings.Builder{}
 
@@ -169,12 +156,7 @@ func testMessageItemsFromLines(hundreds int, limits types.MessageLimit, repeat i
 		}
 	}
 
-	items, omitted = MessageItemsFromLines(builder.String(), limits)
-
-	maxChunkSize := Min(limits.ChunkSize, repeat*100)
-
-	expectedChunkCount := Min(limits.TotalChunkSize/maxChunkSize, Min(hundreds/repeat, limits.ChunkCount-1))
-	Expect(len(items)).To(Equal(expectedChunkCount), "Chunk count")
+	batches = MessageItemsFromLines(builder.String(), limits)
 
 	return
 }