unity debugging

lua/plugins/debugger.lua

@@ -268,6 +268,62 @@ return {
         end
 
         dap.configurations.c = dap.configurations.cpp
+
+        -- Unity (Mono soft debugger) via Unity's MIT-licensed vscode-unity-debug
+        -- adapter, extracted from its .vsix into stdpath("data")/unity-debug.
+        -- Avoids vstuc, whose license (like vsdbg's) is VS Code only.
+        --
+        -- UnityDebug.exe is patched by unity-debug/install.sh (see patch.cs there;
+        -- original kept as UnityDebug.exe.orig): stock, it only matches editor
+        -- processes named exactly "Unity"/"Unity Editor", but Unity Hub launches
+        -- the editor as "unityhub-unity-editor-<version>". The patch makes it a
+        -- case-insensitive "Unity" prefix match, covering both launch methods and
+        -- any version. Helper processes (UnityPackageManager, import workers...)
+        -- match too, so the adapter picks the real editor by the process_id in
+        -- EditorInstance.json -- which needs the config name to contain "Editor".
+        local unity_debug_exe = vim.fn.stdpath("data") .. "/unity-debug/extension/bin/UnityDebug.exe"
+        local unity_debug_install = vim.fn.stdpath("config") .. "/unity-debug/install.sh"
+        dap.adapters.unity = function(callback)
+            if vim.fn.filereadable(unity_debug_exe) == 0 then
+                vim.notify("Installing Unity debug adapter...")
+                local result = vim.system({ unity_debug_install }, { text = true }):wait()
+                if result.code ~= 0 then
+                    vim.notify("Unity debug adapter install failed:\n" .. result.stderr, vim.log.levels.ERROR)
+                    return
+                end
+            end
+            callback({
+                type = "executable",
+                command = "mono",
+                args = { unity_debug_exe },
+                -- The adapter strips the leading "/" from `path` (a Windows-ism)
+                -- before reading it, so run it from / for the now-relative path
+                -- to resolve.
+                options = { cwd = "/" },
+            })
+        end
+
+        -- Library/EditorInstance.json only exists while the editor is open; the
+        -- adapter reads the editor PID from it to derive the debugger port.
+        -- The Unity project may sit in a repo subfolder, so search upward from
+        -- the buffer first, then downward from cwd.
+        local function unity_editor_instance()
+            local root = vim.fs.root(0, "ProjectSettings")
+            if root then
+                return root .. "/Library/EditorInstance.json"
+            end
+            local found = vim.fs.find("EditorInstance.json", { path = vim.fn.getcwd(), type = "file", limit = 1 })
+            return found[1]
+        end
+
+        dap.configurations.cs = {
+            {
+                name = "Unity Editor",
+                type = "unity",
+                request = "launch", -- unity-debug attaches to the running editor despite "launch"
+                path = unity_editor_instance,
+            },
+        }
     end
 }