add tests coverage for nodejs module

Author: timhugh

tests/test_nodejs.lua

@@ -0,0 +1,147 @@
+local eq = MiniTest.expect.equality
+
+local T = MiniTest.new_set({
+  hooks = {
+    pre_once = function() end,
+    pre_case = function()
+      -- Reset the module state before each test
+      package.loaded["copilot.lsp.nodejs"] = nil
+    end,
+  },
+})
+
+T["get_node_version()"] = MiniTest.new_set()
+
+local function stub_process(stdout, code, fail, callback)
+  local captured_args = nil
+  local original_vim_system = vim.system
+  vim.system = function(cmd, opts)
+    captured_args = cmd
+    if fail then
+      error("Command failed")
+    end
+    return {
+      wait = function()
+        return {
+          stdout = stdout .. "\n",
+          code = code
+        }
+      end
+    }
+  end
+  callback()
+  vim.system = original_vim_system
+  return captured_args
+end
+
+T["get_node_version()"]["default node command"] = function()
+  captured_args = stub_process("v20.10.0", 0, false, function()
+    local nodejs = require("copilot.lsp.nodejs")
+    nodejs.setup()
+
+    local version, error = nodejs.get_node_version()
+
+    eq(version, "20.10.0")
+    eq(error, nil)
+  end)
+  eq(captured_args, { "node", "--version" })
+end
+
+T["get_node_version()"]["custom node command as string"] = function()
+  local captured_args = stub_process("v20.10.0", 0, false, function()
+    local nodejs = require("copilot.lsp.nodejs")
+    nodejs.setup("/usr/local/bin/node")
+
+    local version, error = nodejs.get_node_version()
+
+    eq(version, "20.10.0")
+    eq(error, nil)
+  end)
+  eq(captured_args, { "/usr/local/bin/node", "--version" })
+end
+
+T["get_node_version()"]["custom node command as string with spaces"] = function()
+  local captured_args = stub_process("v20.10.0", 0, false, function()
+    local nodejs = require("copilot.lsp.nodejs")
+    nodejs.setup("/path to/node")
+
+    local version, error = nodejs.get_node_version()
+
+    eq(version, "20.10.0")
+    eq(error, nil)
+  end)
+  eq(captured_args, { "/path to/node", "--version" })
+end
+
+T["get_node_version()"]["handles vim.system failure"] = function()
+  local captured_args = stub_process("", -1, true, function()
+    local nodejs = require("copilot.lsp.nodejs")
+    nodejs.setup("node")
+
+    local version, error = nodejs.get_node_version()
+
+    eq(version, "")
+    -- Error should contain failure information
+    local expected_error_pattern = "Could not determine Node%.js version"
+    eq(type(error), "string")
+    eq(error:find(expected_error_pattern) ~= nil, true)
+  end)
+end
+
+T["get_node_version()"]["handles process with non-zero exit code"] = function()
+  local captured_args = stub_process("", 127, false, function()
+    local nodejs = require("copilot.lsp.nodejs")
+    nodejs.setup("nonexistent-node")
+
+    local version, error = nodejs.get_node_version()
+
+    eq(version, "")
+    -- Error should contain failure information with exit code
+    local expected_error_pattern = "Could not determine Node%.js version"
+    eq(type(error), "string")
+    eq(error:find(expected_error_pattern) ~= nil, true)
+    eq(error:find("127") ~= nil, true)
+  end)
+  eq(captured_args, { "nonexistent-node", "--version" })
+end
+
+T["get_node_version()"]["validates node version requirement"] = function()
+  local captured_args = stub_process("v18.17.0", 0, false, function()
+    local nodejs = require("copilot.lsp.nodejs")
+    nodejs.setup("node")
+
+    local version, error = nodejs.get_node_version()
+
+    eq(version, "18.17.0")
+    -- Error should indicate version requirement not met
+    eq(type(error), "string")
+    eq(error:find("Node%.js version 20 or newer required") ~= nil, true)
+    eq(error:find("18%.17%.0") ~= nil, true)
+  end)
+  eq(captured_args, { "node", "--version" })
+end
+
+T["get_execute_command()"] = MiniTest.new_set()
+
+T["get_execute_command()"]["default node command"] = function()
+  local nodejs = require("copilot.lsp.nodejs")
+  nodejs.setup()
+  local cmd = nodejs.get_execute_command()
+  eq(cmd, { "node", nodejs.server_path, "--stdio" })
+end
+
+T["get_execute_command()"]["custom node command as string"] = function()
+  local nodejs = require("copilot.lsp.nodejs")
+  nodejs.setup("/usr/local/bin/node")
+  local cmd = nodejs.get_execute_command()
+  eq(cmd, { "/usr/local/bin/node", nodejs.server_path, "--stdio" })
+end
+
+T["get_execute_command()"]["custom node command as string with spaces"] = function()
+  local nodejs = require("copilot.lsp.nodejs")
+  nodejs.setup("/path to/node")
+  local cmd = nodejs.get_execute_command()
+  eq(cmd, { "/path to/node", nodejs.server_path, "--stdio" })
+end
+
+return T