Step 78: line numbers and gutter

editor/tests/step78_test.cpp

@@ -0,0 +1,88 @@
+// Step 78 TDD Test: Line numbers and gutter
+//
+// Tests:
+// 1. Line count matches content
+// 2. Gutter width grows with line count
+
+#include <cassert>
+#include <iostream>
+#include "imgui.h"
+#include "CodeEditorWidget.h"
+
+static void beginFrame() {
+    ImGuiIO& io = ImGui::GetIO();
+    io.DisplaySize = ImVec2(800, 600);
+    io.DeltaTime = 1.0f / 60.0f;
+    ImGui::NewFrame();
+}
+
+static void endFrame() {
+    ImGui::Render();
+}
+
+static std::string makeLines(int count) {
+    std::string s;
+    for (int i = 0; i < count; ++i) {
+        s += "line";
+        s += std::to_string(i);
+        s += "\n";
+    }
+    return s;
+}
+
+int main() {
+    int passed = 0;
+    int failed = 0;
+
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    ImGui::StyleColorsDark();
+    ImGuiIO& io = ImGui::GetIO();
+    io.Fonts->AddFontDefault();
+    io.Fonts->Build();
+
+    // --- Test 1: Line count ---
+    {
+        beginFrame();
+        ImGui::SetNextWindowFocus();
+        ImGui::Begin("TestWindow");
+        CodeEditorWidget widget;
+        std::string text = makeLines(5);
+        std::vector<HighlightSpan> spans;
+        CodeEditorOptions opts;
+        CodeEditorResult res = widget.render("##editor", text, spans, opts, ImVec2(300, 200), ImGui::GetFont());
+        ImGui::End();
+        endFrame();
+
+        assert(res.lineCount == 5 && "Line count should match content");
+        std::cout << "Test 1 PASS: Line count correct" << std::endl;
+        ++passed;
+    }
+
+    // --- Test 2: Gutter width grows with line count ---
+    {
+        beginFrame();
+        ImGui::SetNextWindowFocus();
+        ImGui::Begin("TestWindow2");
+        CodeEditorWidget widget;
+        std::string shortText = makeLines(9);
+        std::string longText = makeLines(120);
+        std::vector<HighlightSpan> spans;
+        CodeEditorOptions opts;
+
+        CodeEditorResult res1 = widget.render("##editor2", shortText, spans, opts, ImVec2(300, 200), ImGui::GetFont());
+        CodeEditorResult res2 = widget.render("##editor3", longText, spans, opts, ImVec2(300, 200), ImGui::GetFont());
+        ImGui::End();
+        endFrame();
+
+        assert(res1.gutterWidth > 0.0f && res2.gutterWidth > 0.0f);
+        assert(res2.gutterWidth > res1.gutterWidth && "Gutter should grow for more digits");
+        std::cout << "Test 2 PASS: Gutter width grows" << std::endl;
+        ++passed;
+    }
+
+    ImGui::DestroyContext();
+
+    std::cout << "\n=== Step 78 Results: " << passed << " passed, " << failed << " failed ===" << std::endl;
+    return failed > 0 ? 1 : 0;
+}