From 7eb4b154c2d0425e2e70b2927d75d20d30727922 Mon Sep 17 00:00:00 2001
From: "Alexander A. Klimov" <alexander.klimov@icinga.com>
Date: Tue, 23 Jul 2024 09:37:08 +0200
Subject: [PATCH] Test com.Bulk()

---
 com/bulker_test.go | 129 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 com/bulker_test.go

diff --git a/com/bulker_test.go b/com/bulker_test.go
new file mode 100644
index 00000000..9e61d90b
--- /dev/null
+++ b/com/bulker_test.go
@@ -0,0 +1,129 @@
+package com
+
+import (
+	"context"
+	"github.com/stretchr/testify/require"
+	"testing"
+	"time"
+)
+
+func TestBulk(t *testing.T) {
+	noSp := NeverSplit[string]
+	var closeContext []string = nil
+
+	subtests := []struct {
+		name   string
+		input  [][]string
+		count  int
+		spf    BulkChunkSplitPolicyFactory[string]
+		output [][]string
+	}{
+		{"empty", nil, 1, noSp, nil},
+		{"negative", [][]string{{"a"}}, -1, noSp, [][]string{{"a"}}},
+		{"a0", [][]string{{"a"}}, 0, noSp, [][]string{{"a"}}},
+		{"a1", [][]string{{"a"}}, 1, noSp, [][]string{{"a"}}},
+		{"a2", [][]string{{"a"}}, 2, noSp, [][]string{{"a"}}},
+		{"ab1", [][]string{{"a", "b"}}, 1, noSp, [][]string{{"a"}, {"b"}}},
+		{"ab2", [][]string{{"a", "b"}}, 2, noSp, [][]string{{"a", "b"}}},
+		{"ab3", [][]string{{"a", "b"}}, 3, noSp, [][]string{{"a", "b"}}},
+		{"abc1", [][]string{{"a", "b", "c"}}, 1, noSp, [][]string{{"a"}, {"b"}, {"c"}}},
+		{"abc2", [][]string{{"a", "b", "c"}}, 2, noSp, [][]string{{"a", "b"}, {"c"}}},
+		{"abc3", [][]string{{"a", "b", "c"}}, 3, noSp, [][]string{{"a", "b", "c"}}},
+		{"abc4", [][]string{{"a", "b", "c"}}, 4, noSp, [][]string{{"a", "b", "c"}}},
+		{
+			"chunks_by_timeout", [][]string{{"a", "b", "c", "d"}, {"e", "f", "g"}, {"h", "i"}, {"j"}}, 5,
+			noSp, [][]string{{"a", "b", "c", "d"}, {"e", "f", "g"}, {"h", "i"}, {"j"}},
+		},
+		{"chunks_by_spf", [][]string{{"a", "b", "c", "d", "e", "f", "g"}}, 2, func() BulkChunkSplitPolicy[string] {
+			return func(string) bool { return true }
+		}, [][]string{{"a"}, {"b"}, {"c"}, {"d"}, {"e"}, {"f"}, {"g"}}},
+		{"close-ctx_a1", [][]string{closeContext, {"a"}}, 1, noSp, nil},
+		{"close-ctx_a4", [][]string{closeContext, {"a"}}, 4, noSp, nil},
+		{"a_close-ctx_b1", [][]string{{"a"}, closeContext, {"b"}}, 1, noSp, [][]string{{"a"}}},
+		{"a_close-ctx_b4", [][]string{{"a"}, closeContext, {"b"}}, 4, noSp, [][]string{{"a"}}},
+		{"ab_close-ctx_c1", [][]string{{"a", "b"}, closeContext, {"c"}}, 1, noSp, [][]string{{"a"}, {"b"}}},
+		{"ab_close-ctx_c4", [][]string{{"a", "b"}, closeContext, {"c"}}, 4, noSp, [][]string{{"a", "b"}}},
+	}
+
+	latencies := []struct {
+		name    string
+		latency time.Duration
+	}{
+		{"instantly", 0},
+		{"1us", time.Microsecond},
+		{"20ms", 20 * time.Millisecond},
+	}
+
+	for _, st := range subtests {
+		t.Run(st.name, func(t *testing.T) {
+			for _, l := range latencies {
+				t.Run(l.name, func(t *testing.T) {
+					ctx, cancel := context.WithCancel(context.Background())
+					defer cancel()
+
+					bulkCtx, cancelBulk := context.WithCancel(ctx)
+
+					ch := make(chan string, 1)
+					go func() {
+						defer close(ch)
+
+						for i, chunk := range st.input {
+							if i > 0 {
+								select {
+								case <-time.After(time.Second / 2):
+								case <-ctx.Done():
+									return
+								}
+							}
+
+							if chunk == nil {
+								cancelBulk()
+							}
+
+							for _, v := range chunk {
+								if l.latency > 0 {
+									select {
+									case <-time.After(l.latency):
+									case <-ctx.Done():
+										return
+									}
+								}
+
+								select {
+								case ch <- v:
+								case <-ctx.Done():
+									return
+								}
+							}
+						}
+					}()
+
+					output := Bulk(bulkCtx, ch, st.count, st.spf)
+					require.NotNil(t, output)
+
+					for _, expected := range st.output {
+						select {
+						case actual, ok := <-output:
+							if !ok {
+								require.Fail(t, "channel should not be closed, yet")
+							}
+
+							require.Equal(t, expected, actual)
+						case <-time.After(time.Second):
+							require.Fail(t, "channel should not block")
+						}
+					}
+
+					select {
+					case _, ok := <-output:
+						if ok {
+							require.Fail(t, "channel should be closed")
+						}
+					case <-time.After(time.Second):
+						require.Fail(t, "channel should not block")
+					}
+				})
+			}
+		})
+	}
+}