Revamp unit tests (#1368)

* Revamp unit tests
* Increase coverage
* Use go-acc to get cross packages coverage

Signed-off-by: Shivam Sandbhor <shivam.sandbhor@gmail.com>

pkg/csplugin/watcher_test.go

@@ -0,0 +1,107 @@
+package csplugin
+
+import (
+	"context"
+	"log"
+	"testing"
+	"time"
+
+	"github.com/crowdsecurity/crowdsec/pkg/models"
+	"gopkg.in/tomb.v2"
+	"gotest.tools/v3/assert"
+)
+
+var ctx = context.Background()
+
+func resetTestTomb(testTomb *tomb.Tomb) {
+	testTomb.Kill(nil)
+	if err := testTomb.Wait(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func resetWatcherAlertCounter(pw *PluginWatcher) {
+	for k := range pw.AlertCountByPluginName {
+		pw.AlertCountByPluginName[k] = 0
+	}
+}
+
+func insertNAlertsToPlugin(pw *PluginWatcher, n int, pluginName string) {
+	for i := 0; i < n; i++ {
+		pw.Inserts <- pluginName
+	}
+}
+
+func listenChannelWithTimeout(ctx context.Context, channel chan string) error {
+	select {
+	case <-channel:
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+	return nil
+}
+
+func TestPluginWatcherInterval(t *testing.T) {
+	pw := PluginWatcher{}
+	alertsByPluginName := make(map[string][]*models.Alert)
+	testTomb := tomb.Tomb{}
+	configs := map[string]PluginConfig{
+		"testPlugin": {
+			GroupWait: time.Millisecond,
+		},
+	}
+	pw.Init(configs, alertsByPluginName)
+	pw.Start(&testTomb)
+
+	ct, cancel := context.WithTimeout(ctx, time.Microsecond)
+	defer cancel()
+	err := listenChannelWithTimeout(ct, pw.PluginEvents)
+	assert.ErrorContains(t, err, "context deadline exceeded")
+
+	resetTestTomb(&testTomb)
+	testTomb = tomb.Tomb{}
+	pw.Start(&testTomb)
+
+	ct, cancel = context.WithTimeout(ctx, time.Millisecond*5)
+	defer cancel()
+	err = listenChannelWithTimeout(ct, pw.PluginEvents)
+	assert.NilError(t, err)
+	resetTestTomb(&testTomb)
+	// This is to avoid the int complaining
+}
+
+func TestPluginAlertCountWatcher(t *testing.T) {
+	pw := PluginWatcher{}
+	alertsByPluginName := make(map[string][]*models.Alert)
+	configs := map[string]PluginConfig{
+		"testPlugin": {
+			GroupThreshold: 5,
+		},
+	}
+	testTomb := tomb.Tomb{}
+	pw.Init(configs, alertsByPluginName)
+	pw.Start(&testTomb)
+
+	// Channel won't contain any events since threshold is not crossed.
+	ct, cancel := context.WithTimeout(ctx, time.Second)
+	defer cancel()
+	err := listenChannelWithTimeout(ct, pw.PluginEvents)
+	assert.ErrorContains(t, err, "context deadline exceeded")
+
+	// Channel won't contain any events since threshold is not crossed.
+	resetWatcherAlertCounter(&pw)
+	insertNAlertsToPlugin(&pw, 4, "testPlugin")
+	ct, cancel = context.WithTimeout(ctx, time.Second)
+	defer cancel()
+	err = listenChannelWithTimeout(ct, pw.PluginEvents)
+	assert.ErrorContains(t, err, "context deadline exceeded")
+
+	// Channel will contain an event since threshold is crossed.
+	resetWatcherAlertCounter(&pw)
+	insertNAlertsToPlugin(&pw, 5, "testPlugin")
+	ct, cancel = context.WithTimeout(ctx, time.Second)
+	defer cancel()
+	err = listenChannelWithTimeout(ct, pw.PluginEvents)
+	assert.NilError(t, err)
+	resetTestTomb(&testTomb)
+}