feat(StartAgent): split task + prompt

Also use local overrides when set.  Useful for repos where there's a
gitignored local agents dir.

Author: david-hamilton-glean

packages/nvim/lua/hjdivad/agent.lua

@@ -6,53 +6,89 @@ local agents = {
   cursor = "cursor-agent --force --approve-mcps",
 }
 
+local function session_name(cwd)
+  local path_parts = {}
+  for part in string.gmatch(cwd, "[^/]+") do
+    table.insert(path_parts, part)
+  end
+
+  if #path_parts >= 2 then
+    return path_parts[#path_parts - 1] .. "/" .. path_parts[#path_parts]
+  elseif #path_parts == 1 then
+    return path_parts[1]
+  else
+    return "unknown"
+  end
+end
+
+local function env_path(env_name, fallback)
+  local path = vim.env[env_name]
+  if path == nil or path == "" then
+    return fallback
+  end
+
+  return path
+end
+
+local function agent_paths(cwd)
+  local name = session_name(cwd)
+  local base = vim.fn.stdpath("cache") .. "/prompt/" .. name
+
+  return {
+    prompt = env_path("AGENTS_PROMPT", base .. ".prompt.md"),
+    vadnu = env_path("AGENTS_VADNU", base .. ".vadnu.md"),
+  }
+end
+
+local function ensure_parent_dir(path)
+  vim.fn.mkdir(vim.fn.fnamemodify(path, ":h"), "p")
+end
+
+local function ensure_vadnu_file(path)
+  ensure_parent_dir(path)
+
+  if vim.fn.filereadable(path) == 1 then
+    return
+  end
+
+  vim.fn.writefile({ "## Stack", "## Tasks" }, path)
+end
+
 local function do_start_agent(agent_cmd)
-	-- Get current working directory and extract session name
-	local cwd = vim.fn.getcwd()
-	local path_parts = {}
-	for part in string.gmatch(cwd, "[^/]+") do
-		table.insert(path_parts, part)
-	end
-
-	-- Get last two directory components for session name
-	local session_name
-	if #path_parts >= 2 then
-		session_name = path_parts[#path_parts - 1] .. "/" .. path_parts[#path_parts]
-	elseif #path_parts == 1 then
-		session_name = path_parts[1]
-	else
-		session_name = "unknown"
-	end
-
-	-- Create prompt file path
-	local prompt_path = vim.fn.stdpath('cache') .. "/prompt/" .. session_name .. ".prompt.md"
-
-	-- Ensure directory exists
-	local prompt_dir = vim.fn.fnamemodify(prompt_path, ":h")
-	vim.fn.mkdir(prompt_dir, "p")
-
-	-- Open new tab
-	vim.cmd("tabnew")
-
-	-- Split vertically (creates left and right windows)
-	vim.cmd("vsplit")
-
-	-- Move to right window and start terminal with claude
-	vim.cmd("wincmd l") -- Move to right window
-	vim.cmd("term " .. agent_cmd)
-
-	-- Move to left window and open prompt file
-	vim.cmd("wincmd h") -- Move to left window
-	vim.cmd("edit " .. prompt_path)
+  local paths = agent_paths(vim.fn.getcwd())
+
+  ensure_vadnu_file(paths.vadnu)
+  ensure_parent_dir(paths.prompt)
+
+  vim.cmd("tabnew")
+  vim.cmd("rightbelow vsplit")
+  vim.cmd("rightbelow vsplit")
+  vim.cmd("term " .. agent_cmd)
+  vim.cmd("wincmd h")
+  vim.cmd("edit " .. vim.fn.fnameescape(paths.vadnu))
+  vim.cmd("rightbelow split")
+  vim.cmd("edit " .. vim.fn.fnameescape(paths.prompt))
+  vim.cmd("wincmd h")
+  vim.cmd("terminal")
+  vim.cmd("rightbelow split")
+  vim.cmd("terminal")
+  vim.cmd("wincmd l")
+  vim.defer_fn(function()
+    vim.cmd("wincmd =")
+  end, 100)
 end
 
 function M.StartAgent(agent)
-  local agent_name = agent or 'claude'
+  local agent_name = agent or "claude"
   local agent_cmd = agents[agent_name]
   --FIXME: when we execute this eagerly, we run before the autocmds are set up and we don't get the prompt extensions.
   -- But when we execute in a VeryLazy callback, the filetype is never set, for some unknown reason.
   -- For now just execute eagerly, but we probably want to actually do this in a callback
   do_start_agent(agent_cmd)
 end
 
+M._agent_paths = agent_paths
+M._ensure_vadnu_file = ensure_vadnu_file
+M._session_name = session_name
+
 return M

packages/nvim/tests/hjdivad/agent_spec.lua

@@ -0,0 +1,149 @@
+describe("agent", function()
+  local assert = require("luassert")
+  local stub = require("luassert.stub")
+  local agent = require("hjdivad.agent")
+
+  local original_agents_prompt
+  local original_agents_vadnu
+  local stdpath_stub
+  local getcwd_stub
+  local original_cmd
+  local original_defer_fn
+
+  local function restore_env()
+    vim.env.AGENTS_PROMPT = original_agents_prompt
+    vim.env.AGENTS_VADNU = original_agents_vadnu
+  end
+
+  before_each(function()
+    original_agents_prompt = vim.env.AGENTS_PROMPT
+    original_agents_vadnu = vim.env.AGENTS_VADNU
+    vim.env.AGENTS_PROMPT = nil
+    vim.env.AGENTS_VADNU = nil
+    original_cmd = vim.cmd
+    original_defer_fn = vim.defer_fn
+  end)
+
+  after_each(function()
+    restore_env()
+
+    if stdpath_stub then
+      stdpath_stub:revert()
+      stdpath_stub = nil
+    end
+
+    if getcwd_stub then
+      getcwd_stub:revert()
+      getcwd_stub = nil
+    end
+
+    vim.cmd = original_cmd
+    vim.defer_fn = original_defer_fn
+  end)
+
+  describe("_agent_paths", function()
+    it("uses cache prompt paths as fallbacks", function()
+      stdpath_stub = stub(vim.fn, "stdpath", function(name)
+        assert.equals("cache", name)
+        return "/cache"
+      end)
+
+      assert.same({
+        prompt = "/cache/prompt/github/repo.prompt.md",
+        vadnu = "/cache/prompt/github/repo.vadnu.md",
+      }, agent._agent_paths("/Users/me/github/repo"))
+    end)
+
+    it("uses env var paths without expanding them", function()
+      stdpath_stub = stub(vim.fn, "stdpath", function()
+        return "/cache"
+      end)
+      vim.env.AGENTS_PROMPT = "relative/prompt.md"
+      vim.env.AGENTS_VADNU = "~/relative/vadnu.md"
+
+      assert.same({
+        prompt = "relative/prompt.md",
+        vadnu = "~/relative/vadnu.md",
+      }, agent._agent_paths("/Users/me/github/repo"))
+    end)
+
+    it("falls back independently for unset env vars", function()
+      stdpath_stub = stub(vim.fn, "stdpath", function()
+        return "/cache"
+      end)
+      vim.env.AGENTS_PROMPT = "prompt.md"
+
+      assert.same({
+        prompt = "prompt.md",
+        vadnu = "/cache/prompt/github/repo.vadnu.md",
+      }, agent._agent_paths("/Users/me/github/repo"))
+    end)
+  end)
+
+  describe("_ensure_vadnu_file", function()
+    it("creates vadnu.md with initial sections when missing", function()
+      local path = vim.fn.tempname() .. "/vadnu.md"
+
+      agent._ensure_vadnu_file(path)
+
+      assert.same({ "## Stack", "## Tasks" }, vim.fn.readfile(path))
+    end)
+
+    it("leaves existing vadnu.md content alone", function()
+      local path = vim.fn.tempname() .. "/vadnu.md"
+      vim.fn.mkdir(vim.fn.fnamemodify(path, ":h"), "p")
+      vim.fn.writefile({ "custom" }, path)
+
+      agent._ensure_vadnu_file(path)
+
+      assert.same({ "custom" }, vim.fn.readfile(path))
+    end)
+  end)
+
+  describe("StartAgent", function()
+    it("opens the three-column agent layout with terminals on the left and vadnu above prompt in the middle", function()
+      local root = vim.fn.tempname()
+      vim.env.AGENTS_VADNU = root .. "/vadnu.md"
+      vim.env.AGENTS_PROMPT = root .. "/prompt.md"
+      getcwd_stub = stub(vim.fn, "getcwd", function()
+        return "/Users/me/github/repo"
+      end)
+
+      local commands = {}
+      local deferred
+      local defer_delay
+      vim.cmd = function(cmd)
+        table.insert(commands, cmd)
+      end
+      vim.defer_fn = function(callback, delay)
+        deferred = callback
+        defer_delay = delay
+      end
+
+      agent.StartAgent("cursor")
+
+      assert.same({
+        "tabnew",
+        "rightbelow vsplit",
+        "rightbelow vsplit",
+        "term cursor-agent --force --approve-mcps",
+        "wincmd h",
+        "edit " .. vim.fn.fnameescape(vim.env.AGENTS_VADNU),
+        "rightbelow split",
+        "edit " .. vim.fn.fnameescape(vim.env.AGENTS_PROMPT),
+        "wincmd h",
+        "terminal",
+        "rightbelow split",
+        "terminal",
+        "wincmd l",
+      }, commands)
+      assert.same({ "## Stack", "## Tasks" }, vim.fn.readfile(vim.env.AGENTS_VADNU))
+      assert.equals(0, vim.fn.filereadable(vim.env.AGENTS_PROMPT))
+
+      assert.is_function(deferred)
+      assert.equals(100, defer_delay)
+      deferred()
+      assert.equals("wincmd =", commands[#commands])
+    end)
+  end)
+end)