Add new test

internal/parser/parser_test.go

@@ -3,6 +3,7 @@ package parser
 import (
 	"os"
 	"testing"
+	"time"
 )
 
 func TestNewScanner(t *testing.T) {
@@ -20,3 +21,79 @@ func TestNewScanner(t *testing.T) {
 		t.Fatal("Scanner is nil")
 	}
 }
+
+func TestScannerStart(t *testing.T) {
+	tests := []struct {
+		name      string
+		input     string
+		wantErr   bool
+		wantLines int
+	}{
+		{
+			name: "correct file",
+			input: `Failed password for root from 192.168.1.1
+Invalid user admin from 192.168.1.1
+Accepted publickey for user from 192.168.1.2`,
+			wantErr:   false,
+			wantLines: 3,
+		},
+		{
+			name:      "empty file",
+			input:     "",
+			wantErr:   false,
+			wantLines: 0,
+		},
+		{
+			name:      "single line",
+			input:     `Failed password for root`,
+			wantErr:   false,
+			wantLines: 1,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			file, err := os.CreateTemp("", "test-*.log")
+			if err != nil {
+				t.Fatal(err)
+			}
+			filePath := file.Name()
+
+			if _, err := file.WriteString(tt.input); err != nil {
+				t.Fatal(err)
+			}
+			file.Close()
+			defer os.Remove(filePath)
+
+			scanner, err := NewScanner(filePath)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("NewScanner() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+
+			if tt.wantErr {
+				return
+			}
+			defer scanner.Stop()
+
+			scanner.Start()
+
+			timeout := time.After(500 * time.Millisecond)
+			linesRead := 0
+
+			for {
+				select {
+				case event := <-scanner.Events():
+					linesRead++
+					t.Logf("Read: %s", event.Data)
+				case <-timeout:
+					if linesRead != tt.wantLines {
+						t.Errorf("got %d lines, want %d", linesRead, tt.wantLines)
+					}
+					return
+				}
+			}
+		})
+	}
+}