From 4031593ea8871d3d0883ee92b4316af4d27cb7e1 Mon Sep 17 00:00:00 2001
From: djuka <djuka@local>
Date: Sat, 21 Feb 2026 04:35:20 +0000
Subject: [PATCH] T26: Testovi za endpoint zadnjih 20 linija loga

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 code/internal/server/logs_test.go | 161 ++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 code/internal/server/logs_test.go

diff --git a/code/internal/server/logs_test.go b/code/internal/server/logs_test.go
new file mode 100644
index 0000000..3b7c29f
--- /dev/null
+++ b/code/internal/server/logs_test.go
@@ -0,0 +1,161 @@
+package server
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestHandleLogsTail_OK(t *testing.T) {
+	srv := setupTestServer(t)
+
+	logFile := filepath.Join(t.TempDir(), "test.log")
+	lines := make([]string, 25)
+	for i := range lines {
+		lines[i] = "linija " + string(rune('A'+i))
+	}
+	os.WriteFile(logFile, []byte(strings.Join(lines, "\n")+"\n"), 0644)
+	srv.Config.LogFile = logFile
+
+	req := httptest.NewRequest(http.MethodGet, "/api/logs/tail", nil)
+	w := httptest.NewRecorder()
+	srv.Router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+
+	got := strings.Split(strings.TrimRight(w.Body.String(), "\n"), "\n")
+	if len(got) != maxLogLines {
+		t.Fatalf("expected %d lines, got %d", maxLogLines, len(got))
+	}
+	// First returned line should be line 6 (index 5) since we have 25 lines, tail 20
+	if got[0] != "linija F" {
+		t.Errorf("expected first line 'linija F', got %q", got[0])
+	}
+}
+
+func TestHandleLogsTail_LessThan20Lines(t *testing.T) {
+	srv := setupTestServer(t)
+
+	logFile := filepath.Join(t.TempDir(), "test.log")
+	os.WriteFile(logFile, []byte("prva\ndruga\ntreca\n"), 0644)
+	srv.Config.LogFile = logFile
+
+	req := httptest.NewRequest(http.MethodGet, "/api/logs/tail", nil)
+	w := httptest.NewRecorder()
+	srv.Router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+
+	got := strings.Split(strings.TrimRight(w.Body.String(), "\n"), "\n")
+	if len(got) != 3 {
+		t.Fatalf("expected 3 lines, got %d", len(got))
+	}
+}
+
+func TestHandleLogsTail_NoLogFile(t *testing.T) {
+	srv := setupTestServer(t)
+	// LogFile is empty string by default in test config
+
+	req := httptest.NewRequest(http.MethodGet, "/api/logs/tail", nil)
+	w := httptest.NewRecorder()
+	srv.Router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+
+	if !strings.Contains(w.Body.String(), "KAOS_LOG_FILE") {
+		t.Error("expected message about KAOS_LOG_FILE not being set")
+	}
+}
+
+func TestHandleLogsTail_FileNotFound(t *testing.T) {
+	srv := setupTestServer(t)
+	srv.Config.LogFile = "/tmp/nonexistent-kaos-test-log-12345.log"
+
+	req := httptest.NewRequest(http.MethodGet, "/api/logs/tail", nil)
+	w := httptest.NewRecorder()
+	srv.Router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+
+	if !strings.Contains(w.Body.String(), "ne postoji") {
+		t.Error("expected message about file not existing")
+	}
+}
+
+func TestHandleLogsTail_Max20Lines(t *testing.T) {
+	srv := setupTestServer(t)
+
+	logFile := filepath.Join(t.TempDir(), "test.log")
+	lines := make([]string, 100)
+	for i := range lines {
+		lines[i] = "log line"
+	}
+	os.WriteFile(logFile, []byte(strings.Join(lines, "\n")+"\n"), 0644)
+	srv.Config.LogFile = logFile
+
+	req := httptest.NewRequest(http.MethodGet, "/api/logs/tail", nil)
+	w := httptest.NewRecorder()
+	srv.Router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+
+	got := strings.Split(strings.TrimRight(w.Body.String(), "\n"), "\n")
+	if len(got) > maxLogLines {
+		t.Errorf("expected max %d lines, got %d", maxLogLines, len(got))
+	}
+}
+
+func TestTailLines(t *testing.T) {
+	tests := []struct {
+		name     string
+		text     string
+		n        int
+		expected int
+	}{
+		{"empty", "", 20, 1},
+		{"less than n", "a\nb\nc", 20, 3},
+		{"exact n", "a\nb\nc", 3, 3},
+		{"more than n", "a\nb\nc\nd\ne", 3, 3},
+		{"trailing newline", "a\nb\nc\n", 2, 2},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := tailLines(tt.text, tt.n)
+			if len(got) != tt.expected {
+				t.Errorf("tailLines(%q, %d) = %d lines, want %d", tt.text, tt.n, len(got), tt.expected)
+			}
+		})
+	}
+}
+
+func TestTailLines_Content(t *testing.T) {
+	text := "first\nsecond\nthird\nfourth\nfifth\n"
+	got := tailLines(text, 3)
+
+	if len(got) != 3 {
+		t.Fatalf("expected 3 lines, got %d", len(got))
+	}
+	if got[0] != "third" {
+		t.Errorf("expected 'third', got %q", got[0])
+	}
+	if got[1] != "fourth" {
+		t.Errorf("expected 'fourth', got %q", got[1])
+	}
+	if got[2] != "fifth" {
+		t.Errorf("expected 'fifth', got %q", got[2])
+	}
+}