1 files changed, 130 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/agent/discovery/file/sim_test.go b/src/go/collectors/go.d.plugin/agent/discovery/file/sim_test.go
new file mode 100644
index 000000000..cd9fa05ac
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/agent/discovery/file/sim_test.go
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package file
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"sort"
+	"testing"
+	"time"
+
+	"github.com/netdata/netdata/go/go.d.plugin/agent/confgroup"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v2"
+)
+
+type (
+	discoverySim struct {
+		discovery      *Discovery
+		beforeRun      func()
+		afterRun       func()
+		expectedGroups []*confgroup.Group
+	}
+)
+
+func (sim discoverySim) run(t *testing.T) {
+	t.Helper()
+	require.NotNil(t, sim.discovery)
+
+	if sim.beforeRun != nil {
+		sim.beforeRun()
+	}
+
+	in, out := make(chan []*confgroup.Group), make(chan []*confgroup.Group)
+	go sim.collectGroups(t, in, out)
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	go sim.discovery.Run(ctx, in)
+	time.Sleep(time.Millisecond * 250)
+
+	if sim.afterRun != nil {
+		sim.afterRun()
+	}
+
+	actual := <-out
+
+	sortGroups(actual)
+	sortGroups(sim.expectedGroups)
+
+	assert.Equal(t, sim.expectedGroups, actual)
+}
+
+func (sim discoverySim) collectGroups(t *testing.T, in, out chan []*confgroup.Group) {
+	timeout := time.Second * 5
+	var groups []*confgroup.Group
+loop:
+	for {
+		select {
+		case updates := <-in:
+			if groups = append(groups, updates...); len(groups) >= len(sim.expectedGroups) {
+				break loop
+			}
+		case <-time.After(timeout):
+			t.Logf("discovery %s timed out after %s, got %d groups, expected %d, some events are skipped",
+				sim.discovery.discoverers, timeout, len(groups), len(sim.expectedGroups))
+			break loop
+		}
+	}
+	out <- groups
+}
+
+type tmpDir struct {
+	dir string
+	t   *testing.T
+}
+
+func newTmpDir(t *testing.T, pattern string) *tmpDir {
+	pattern = "netdata-go-test-discovery-file-" + pattern
+	dir, err := os.MkdirTemp(os.TempDir(), pattern)
+	require.NoError(t, err)
+	return &tmpDir{dir: dir, t: t}
+}
+
+func (d *tmpDir) cleanup() {
+	assert.NoError(d.t, os.RemoveAll(d.dir))
+}
+
+func (d *tmpDir) join(filename string) string {
+	return filepath.Join(d.dir, filename)
+}
+
+func (d *tmpDir) createFile(pattern string) string {
+	f, err := os.CreateTemp(d.dir, pattern)
+	require.NoError(d.t, err)
+	_ = f.Close()
+	return f.Name()
+}
+
+func (d *tmpDir) removeFile(filename string) {
+	err := os.Remove(filename)
+	require.NoError(d.t, err)
+}
+
+func (d *tmpDir) renameFile(origFilename, newFilename string) {
+	err := os.Rename(origFilename, newFilename)
+	require.NoError(d.t, err)
+}
+
+func (d *tmpDir) writeYAML(filename string, in interface{}) {
+	bs, err := yaml.Marshal(in)
+	require.NoError(d.t, err)
+	err = os.WriteFile(filename, bs, 0644)
+	require.NoError(d.t, err)
+}
+
+func (d *tmpDir) writeString(filename, data string) {
+	err := os.WriteFile(filename, []byte(data), 0644)
+	require.NoError(d.t, err)
+}
+
+func sortGroups(groups []*confgroup.Group) {
+	if len(groups) == 0 {
+		return
+	}
+	sort.Slice(groups, func(i, j int) bool { return groups[i].Source < groups[j].Source })
+}