feat: simplify ansi buffer approach

tests/execute_spec.lua

@@ -0,0 +1,116 @@
+local execute = require('cp.execute')
+
+describe('execute module', function()
+  local test_ctx
+  local test_config
+
+  before_each(function()
+    test_ctx = {
+      source_file = 'test.cpp',
+      binary_file = 'build/test',
+      input_file = 'io/test.cpin',
+      output_file = 'io/test.cpout',
+    }
+
+    test_config = {
+      default_language = 'cpp',
+      cpp = {
+        version = 17,
+        compile = { 'g++', '-std=c++17', '-o', '{binary}', '{source}' },
+        test = { '{binary}' },
+        executable = nil,
+      },
+    }
+  end)
+
+  describe('compile_generic', function()
+    it('should use stderr redirection (2>&1)', function()
+      local original_system = vim.system
+      local captured_command = nil
+
+      vim.system = function(cmd, opts)
+        captured_command = cmd
+        return {
+          wait = function()
+            return { code = 0, stdout = '', stderr = '' }
+          end,
+        }
+      end
+
+      local substitutions = { source = 'test.cpp', binary = 'build/test', version = '17' }
+      execute.compile_generic(test_config.cpp, substitutions)
+
+      assert.is_not_nil(captured_command)
+      assert.equals('sh', captured_command[1])
+      assert.equals('-c', captured_command[2])
+      assert.is_true(
+        string.find(captured_command[3], '2>&1') ~= nil,
+        'Command should contain 2>&1 redirection'
+      )
+
+      vim.system = original_system
+    end)
+
+    it('should return combined stdout+stderr in result', function()
+      local original_system = vim.system
+      local test_output = 'STDOUT: Hello\nSTDERR: Error message\n'
+
+      vim.system = function(cmd, opts)
+        return {
+          wait = function()
+            return { code = 1, stdout = test_output, stderr = '' }
+          end,
+        }
+      end
+
+      local substitutions = { source = 'test.cpp', binary = 'build/test', version = '17' }
+      local result = execute.compile_generic(test_config.cpp, substitutions)
+
+      assert.equals(1, result.code)
+      assert.equals(test_output, result.stdout)
+
+      vim.system = original_system
+    end)
+  end)
+
+  describe('compile_problem', function()
+    it('should return combined output in stderr field for compatibility', function()
+      local original_system = vim.system
+      local test_error_output = 'test.cpp:1:1: error: expected declaration\n'
+
+      vim.system = function(cmd, opts)
+        return {
+          wait = function()
+            return { code = 1, stdout = test_error_output, stderr = '' }
+          end,
+        }
+      end
+
+      local result = execute.compile_problem(test_ctx, test_config, false)
+
+      assert.is_false(result.success)
+      assert.equals(test_error_output, result.output)
+
+      vim.system = original_system
+    end)
+
+    it('should return success=true when compilation succeeds', function()
+      local original_system = vim.system
+
+      vim.system = function(cmd, opts)
+        return {
+          wait = function()
+            return { code = 0, stdout = '', stderr = '' }
+          end,
+        }
+      end
+
+      local result = execute.compile_problem(test_ctx, test_config, false)
+
+      assert.is_true(result.success)
+      assert.is_nil(result.output)
+
+      vim.system = original_system
+    end)
+  end)
+end)