fix: invalidate project path cache on project switch

path.lua cached the first project's dirs forever and settings.lua
resolved the workspace dir at module load, so switching projects in
one session kept using the first project's paths. Key path.lua's cache
by the detected project root and resolve settings paths per call.

Author: artur-shaik

lua/jc/path.lua

@@ -1,28 +1,33 @@
 local M = {}
-local paths = nil
+
+-- derived dirs are memoized per project root, so switching between
+-- projects in one session yields the right paths (the old code cached
+-- the first project forever)
+local cache = {}
 
 local function locate_buffer(project_root_file)
   if vim.fn.filereadable(project_root_file) == 1 then
     vim.cmd("lcd " .. vim.fn.fnamemodify(project_root_file, ":h"))
   end
 end
 
-local function find_project_path()
-  local result = {
+local function find_project_path(project_root_file)
+  local project_name = vim.fn.substitute(project_root_file, "[\\/:;.]", "_", "g")
+  return {
     data_dir = vim.fn["project_root#get_basedir"]("data"),
-    project_root_file = vim.fn["project_root#find"](),
+    project_root_file = project_root_file,
+    workspace_dir = vim.fn["project_root#get_basedir"]("workspaces") .. project_name .. "/",
   }
-
-  local project_name = vim.fn.substitute(result.project_root_file, "[\\/:;.]", "_", "g")
-  result.workspace_dir = vim.fn["project_root#get_basedir"]("workspaces") .. project_name .. "/"
-  return result
 end
 
 function M.get_project_dirs()
+  local project_root_file = vim.fn["project_root#find"]()
+  local paths = cache[project_root_file]
   if not paths then
-    paths = find_project_path()
+    paths = find_project_path(project_root_file)
+    cache[project_root_file] = paths
   end
-  locate_buffer(paths.project_root_file)
+  locate_buffer(project_root_file)
   return paths
 end
 

lua/jc/settings.lua

@@ -1,11 +1,15 @@
 local M = {}
 
-local project_name = vim.fn["project_root#get_name"]()
-local workspace_dir = vim.fn["project_root#get_basedir"]("workspaces") .. project_name
+-- resolved per call: the project (and thus the workspace dir) can change
+-- within one session, so this must not be cached at module load
+local function project_file(name)
+  local project_name = vim.fn["project_root#get_name"]()
+  return vim.fn["project_root#get_basedir"]("workspaces") .. project_name .. "." .. name
+end
 
 function M.read_project(name, default)
   local result = default
-  local file_name = workspace_dir .. "." .. name
+  local file_name = project_file(name)
   if vim.fn.filereadable(file_name) == 1 then
     local file = io.open(file_name)
     if file then
@@ -17,8 +21,7 @@ function M.read_project(name, default)
 end
 
 function M.write_project(name, value)
-  local file_name = workspace_dir .. "." .. name
-  local file = io.open(file_name, "w+")
+  local file = io.open(project_file(name), "w+")
   if file then
     file:write(value)
     file:close()

tests/jc/path_spec.lua

@@ -0,0 +1,51 @@
+describe("path cache invalidation", function()
+  local path, settings
+
+  -- create a temp dir with a pom.xml so project_root#find resolves it
+  local function make_project()
+    local dir = vim.fn.tempname()
+    vim.fn.mkdir(dir, "p")
+    vim.fn.writefile({ "<project/>" }, dir .. "/pom.xml")
+    vim.fn.writefile({ "class A {}" }, dir .. "/A.java")
+    return dir
+  end
+
+  local root = vim.fn.getcwd()
+
+  before_each(function()
+    -- editing a project file triggers an lcd into it; restore cwd so the
+    -- relative runtimepath ('.') keeps resolving jc.* modules
+    vim.cmd("cd " .. root)
+    vim.g.jc_basedir = vim.fn.tempname()
+    package.loaded["jc.path"] = nil
+    package.loaded["jc.settings"] = nil
+    path = require("jc.path")
+    settings = require("jc.settings")
+  end)
+
+  it("returns different workspace dirs for different projects", function()
+    local p1 = make_project()
+    vim.cmd("edit " .. p1 .. "/A.java")
+    local ws1 = path.get_workspace_dir()
+
+    local p2 = make_project()
+    vim.cmd("edit " .. p2 .. "/A.java")
+    local ws2 = path.get_workspace_dir()
+
+    assert.are_not.equal(ws1, ws2)
+  end)
+
+  it("settings follow the active project", function()
+    local p1 = make_project()
+    vim.cmd("edit " .. p1 .. "/A.java")
+    settings.write_project("debug-port", "5005")
+
+    local p2 = make_project()
+    vim.cmd("edit " .. p2 .. "/A.java")
+    -- the second project hasn't stored anything yet
+    assert.are.equal("9000", settings.read_project("debug-port", "9000"))
+
+    vim.cmd("edit " .. p1 .. "/A.java")
+    assert.are.equal("5005", settings.read_project("debug-port", "9000"))
+  end)
+end)