Phase 3d complete: editor infrastructure (Steps 55-58)

Step 55: WelcomeScreen (actions, recent files, tips, visibility) - 7/7 tests
Step 56: ElispCommandBuilder + MockEmacsConnection (escaping, daemon lifecycle) - 6/6 tests
Step 57: BufferManager (multi-file open/close/switch, language/modified tracking) - 7/7 tests
Step 58: EditorMode (per-language indent, comment toggle, bracket pairs, snippets) - 8/8 tests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

editor/tests/step55_test.cpp

@@ -0,0 +1,135 @@
+// Step 55 TDD Test: Welcome screen component
+//
+// Verifies that WelcomeScreen:
+// 1. Has default title and subtitle
+// 2. Has default quick actions
+// 3. Recent files can be added and retrieved
+// 4. Tips cycle correctly
+// 5. Visibility toggle works
+// 6. Recent files limit (max 10) and deduplication
+// 7. Version info is accessible
+
+#include <iostream>
+#include <string>
+#include <cassert>
+#include "WelcomeScreen.h"
+
+int main() {
+    int passed = 0;
+    int failed = 0;
+
+    // --- Test 1: Default title and subtitle ---
+    {
+        WelcomeScreen ws;
+        assert(ws.getTitle() == "Whetstone Editor" && "Default title");
+        assert(!ws.getSubtitle().empty() && "Should have a subtitle");
+
+        std::cout << "Test 1 PASS: Default title and subtitle" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 2: Default quick actions ---
+    {
+        WelcomeScreen ws;
+        auto actions = ws.getActions();
+        assert(actions.size() >= 3 && "Should have at least 3 default actions");
+
+        // Check for expected actions
+        bool hasNewFile = false, hasOpenFile = false;
+        for (const auto& a : actions) {
+            if (a.label == "New File") hasNewFile = true;
+            if (a.label == "Open File") hasOpenFile = true;
+        }
+        assert(hasNewFile && "Should have New File action");
+        assert(hasOpenFile && "Should have Open File action");
+
+        std::cout << "Test 2 PASS: Default quick actions present" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 3: Add and retrieve recent files ---
+    {
+        WelcomeScreen ws;
+        ws.addRecentFile("/home/user/test.py", "python");
+        ws.addRecentFile("/home/user/main.cpp", "cpp");
+
+        auto recent = ws.getRecentFiles();
+        assert(recent.size() == 2 && "Should have 2 recent files");
+        // Most recent first
+        assert(recent[0].path == "/home/user/main.cpp" && "Most recent first");
+        assert(recent[0].displayName == "main.cpp" && "Display name extracted");
+        assert(recent[0].language == "cpp" && "Language preserved");
+        assert(recent[1].path == "/home/user/test.py" && "Second file");
+
+        std::cout << "Test 3 PASS: Recent files added and retrieved" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 4: Tips cycle through ---
+    {
+        WelcomeScreen ws;
+        assert(!ws.getTips().empty() && "Should have default tips");
+
+        std::string tip0 = ws.getNextTip();
+        std::string tip1 = ws.getNextTip();
+        assert(!tip0.empty() && "First tip should not be empty");
+        assert(tip0 != tip1 && "Tips should cycle to different values");
+
+        // Cycle back to first
+        size_t numTips = ws.getTips().size();
+        for (size_t i = 2; i < numTips; ++i) ws.getNextTip();
+        std::string tipCycled = ws.getNextTip();
+        assert(tipCycled == tip0 && "Tips should cycle back to first");
+
+        std::cout << "Test 4 PASS: Tips cycle correctly" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 5: Visibility toggle ---
+    {
+        WelcomeScreen ws;
+        assert(ws.isVisible() && "Should be visible by default");
+        ws.hide();
+        assert(!ws.isVisible() && "Should be hidden after hide()");
+        ws.show();
+        assert(ws.isVisible() && "Should be visible after show()");
+
+        std::cout << "Test 5 PASS: Visibility toggle works" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 6: Recent files max limit and dedup ---
+    {
+        WelcomeScreen ws;
+        // Add 12 files
+        for (int i = 0; i < 12; ++i) {
+            ws.addRecentFile("/test/file" + std::to_string(i) + ".py", "python");
+        }
+        auto recent = ws.getRecentFiles();
+        assert(recent.size() == 10 && "Should cap at 10 recent files");
+
+        // Add duplicate — should not increase count
+        ws.clearRecentFiles();
+        ws.addRecentFile("/test/a.py", "python");
+        ws.addRecentFile("/test/a.py", "python");
+        assert(ws.getRecentFiles().size() == 1 && "Duplicate should not be added");
+
+        std::cout << "Test 6 PASS: Recent files limit and deduplication" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 7: Version info ---
+    {
+        WelcomeScreen ws;
+        assert(!ws.getVersion().empty() && "Should have a version");
+        ws.setVersion("1.0.0");
+        assert(ws.getVersion() == "1.0.0" && "Version should be updated");
+
+        std::cout << "Test 7 PASS: Version info accessible" << std::endl;
+        ++passed;
+    }
+
+    // --- Summary ---
+    std::cout << "\n=== Step 55 Results: " << passed << " passed, " << failed << " failed ===" << std::endl;
+    return failed > 0 ? 1 : 0;
+}