feat(go): advance validation sidecar toward production

go-agent/internal/eventlog/read_test.go

@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package eventlog
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestReadRecentSpansRotationInChronologicalOrder(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "events.jsonl")
+	writeLines(t, path+".1", 1, 2, 3)
+	writeLines(t, path, 4, 5)
+	rows, err := ReadRecent(path, 3)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := rowSequences(t, rows); len(got) != 3 || got[0] != 3 || got[1] != 4 || got[2] != 5 {
+		t.Fatalf("sequences=%v", got)
+	}
+}
+
+func TestReadRecentReturnsAllWhenUnderLimit(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "events.jsonl")
+	writeLines(t, path, 7, 8)
+	rows, err := ReadRecent(path, 10)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := rowSequences(t, rows); len(got) != 2 || got[0] != 7 || got[1] != 8 {
+		t.Fatalf("sequences=%v", got)
+	}
+}
+
+func TestReadRecentRejectsCorruptionAndInvalidArguments(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "events.jsonl")
+	if err := os.WriteFile(path, []byte("{not-json}\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := ReadRecent(path, 1); err == nil {
+		t.Fatal("corrupt log accepted")
+	}
+	if _, err := ReadRecent("", 1); err == nil {
+		t.Fatal("empty path accepted")
+	}
+	if _, err := ReadRecent(path, 0); err == nil {
+		t.Fatal("zero limit accepted")
+	}
+}
+
+func writeLines(t *testing.T, path string, sequences ...int) {
+	t.Helper()
+	file, err := os.Create(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file.Close()
+	encoder := json.NewEncoder(file)
+	for _, sequence := range sequences {
+		if err := encoder.Encode(map[string]any{"sequence": sequence}); err != nil {
+			t.Fatal(err)
+		}
+	}
+}
+
+func rowSequences(t *testing.T, rows [][]byte) []int {
+	t.Helper()
+	result := make([]int, 0, len(rows))
+	for _, row := range rows {
+		var record struct {
+			Sequence int `json:"sequence"`
+		}
+		if err := json.Unmarshal(row, &record); err != nil {
+			t.Fatal(err)
+		}
+		result = append(result, record.Sequence)
+	}
+	return result
+}