feat(julials): add JuliaActivateEnv to activate a julia environment

lua/lspconfig/server_configurations/julials.lua

@@ -1,5 +1,54 @@
 local util = require 'lspconfig.util'
 
+local function activate_env(path)
+  local bufnr = vim.api.nvim_get_current_buf()
+  local julials_clients = vim.lsp.get_clients { bufnr = bufnr, name = 'julials' }
+  assert(
+    #julials_clients > 0,
+    'method julia/activateenvironment is not supported by any servers active on the current buffer'
+  )
+  local julia_project_files = { 'Project.toml', 'JuliaProject.toml' }
+  local function _activate_env(environment)
+    if environment then
+      for _, julials_client in ipairs(julials_clients) do
+        julials_client.notify('julia/activateenvironment', { envPath = environment })
+      end
+      vim.notify('Julia environment activated: \n`' .. environment .. '`', vim.log.levels.INFO)
+    end
+  end
+  if path then
+    path = vim.fs.normalize(path)
+    local found_env = false
+    for _, project_file in ipairs(julia_project_files) do
+      if util.path.exists(vim.fs.joinpath(path, project_file)) then
+        found_env = true
+        break
+      end
+    end
+    if not found_env then
+      vim.notify('Path is not a julia environment: \n`' .. path .. '`', vim.log.levels.WARN)
+      return
+    end
+    _activate_env(path)
+  else
+    local depot_paths = vim.env.JULIA_DEPOT_PATH and vim.split(vim.env.JULIA_DEPOT_PATH, ':')
+      or { vim.fn.expand '~/.julia' }
+    local environments = {}
+    vim.list_extend(environments, vim.fs.find(julia_project_files, { type = 'file', upward = true, limit = math.huge }))
+    for _, depot_path in ipairs(depot_paths) do
+      local depot_env = vim.fs.joinpath(vim.fs.normalize(depot_path), 'environments')
+      vim.list_extend(
+        environments,
+        vim.fs.find(function(name, env_path)
+          return vim.tbl_contains(julia_project_files, name) and string.sub(env_path, #depot_env + 1):match '^/[^/]*$'
+        end, { path = depot_env, type = 'file', limit = math.huge })
+      )
+    end
+    environments = vim.tbl_map(vim.fs.dirname, environments)
+    vim.ui.select(environments, { prompt = 'Select a Julia environment' }, _activate_env)
+  end
+end
+
 local cmd = {
   'julia',
   '--startup-file=no',
@@ -49,6 +98,14 @@ return {
     end,
     single_file_support = true,
   },
+  commands = {
+    JuliaActivateEnv = {
+      activate_env,
+      description = 'Activate a Julia environment',
+      nargs = '?',
+      complete = 'file',
+    },
+  },
   docs = {
     description = [[
 https://github.com/julia-vscode/julia-vscode
@@ -70,6 +127,9 @@ Julia project, you must make sure that the project is instantiated:
 ```sh
 julia --project=/path/to/my/project -e 'using Pkg; Pkg.instantiate()'
 ```
+
+Note: The julia programming language searches for global environments within the `environments/`
+folder of `$JULIA_DEPOT_PATH` entries. By default this simply `~/.julia/environments`
     ]],
   },
 }