Step 86: multi-tab editing

editor/tests/step86_test.cpp

@@ -0,0 +1,36 @@
+// Step 86 TDD Test: Multi-tab editing (BufferManager)
+//
+// Tests:
+// 1. Opening buffers sets active
+// 2. Switching active buffer works
+// 3. Closing active buffer selects another
+
+#include <cassert>
+#include <iostream>
+#include "BufferManager.h"
+
+int main() {
+    int passed = 0;
+    int failed = 0;
+
+    BufferManager bm;
+    bm.openBuffer("a.py", "print(1)", "python");
+    assert(bm.getActiveBufferPath() == "a.py");
+    bm.openBuffer("b.py", "print(2)", "python");
+    assert(bm.getActiveBufferPath() == "b.py");
+    std::cout << "Test 1 PASS: Opening buffers sets active" << std::endl;
+    ++passed;
+
+    bm.switchToBuffer("a.py");
+    assert(bm.getActiveBufferPath() == "a.py");
+    std::cout << "Test 2 PASS: Switching active buffer" << std::endl;
+    ++passed;
+
+    bm.closeBuffer("a.py");
+    assert(bm.getActiveBufferPath() == "b.py");
+    std::cout << "Test 3 PASS: Closing active selects another" << std::endl;
+    ++passed;
+
+    std::cout << "\n=== Step 86 Results: " << passed << " passed, " << failed << " failed ===" << std::endl;
+    return failed > 0 ? 1 : 0;
+}