fix ext-processing + add jwt example (#133)

docs/docs/usage/dynamically-setting-environment-variables-based-on-response-json.md

@@ -41,31 +41,29 @@ If the response is a *complex* JSON object,
 you can use the `@env-stdin-cmd` directive to
 set environment variables using an external command (e.g., `jq`).
 
+In this example `jq` is used to extract the `ctx` string from a JWT token.
+
 ```http title="with-external-jq.http"
 POST https://httpbin.org/post HTTP/1.1
 Content-Type: application/json
 Accept: application/json
 # Setting the environment variables to be used in the next request.
 # Any external command can be used to set the environment variables.
 # The command should output the environment variable as string.
-# @env-stdin-cmd AUTH_TOKEN jq -rcj .json.token
-# @env-stdin-cmd AUTH_USERNAME jq -rcj .json.username
+# @env-stdin-cmd JWT_CONTEXT jq -r '.token | gsub("-";"+") | gsub("_";"/") | split(".") | .[1] | @base64d | fromjson | .ctx'
 
 {
-  "username": "{{USERNAME}}",
-  "password": "{{PASSWORD}}",
-  "token": "foobar"
+  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ0eXBlIjoiZ29yaWxsYSIsIm5hbWUiOiJHb3JpbGxhIE1vZSIsImN0eCI6IlNvbWUgY29udGV4dCIsIndlYnNpdGUiOiJodHRwczovL2dvcmlsbGEubW9lIn0.YmEG9bOo1o9opeWnCsfW621A-sB_5WXSBI2FjtvwXlk"
 }
 
 ###
 
 POST https://httpbin.org/post HTTP/1.1
 Content-Type: application/json
 Accept: application/json
-Authorization: Bearer {{AUTH_TOKEN}}
 
 {
   "success": true,
-  "username": "{{AUTH_USERNAME}}"
+  "context": "{{JWT_CONTEXT}}"
 }
 ```

lua/kulala/cmd/shell_utils.lua

@@ -0,0 +1,33 @@
+local M = {}
+
+local cache = {}
+
+M.has_command = function(cmd)
+  return vim.fn.executable(cmd) == 1
+end
+
+M.has_powershell = function()
+  if cache.has_powershell ~= nil then
+    return cache._has_powershell
+  end
+  cache.has_powershell = M.has_command("powershell")
+  return cache.has_powershell
+end
+
+M.has_sh = function()
+  if cache.has_sh ~= nil then
+    return cache.has_sh
+  end
+  cache.has_sh = M.has_command("sh")
+  return cache.has_sh
+end
+
+M.has_zsh = function()
+  if cache.has_zsh ~= nil then
+    return cache.has_zsh
+  end
+  cache.has_zsh = M.has_command("zsh")
+  return cache.has_zsh
+end
+
+return M

lua/kulala/external_processing/init.lua

@@ -1,26 +1,47 @@
 local FS = require("kulala.utils.fs")
+local ShellUtils = require("kulala.cmd.shell_utils")
 local DB = require("kulala.db")
+local Logger = require("kulala.logger")
 
 local M = {}
 
 M.env_stdin_cmd = function(cmdstring, contents)
   local cmd = {}
-  local splitted = vim.split(cmdstring, " ")
-  local env_name = splitted[1]
-  local cmd_exists = FS.command_exists(splitted[2])
-  if not cmd_exists then
-    vim.notify("env_stdin_cmd --> Command not found: " .. cmd[2] .. ".", vim.log.levels.ERROR)
+  if ShellUtils.has_sh() then
+    -- Use sh on Unix-like systems
+    table.insert(cmd, "sh")
+    table.insert(cmd, "-c")
+  elseif ShellUtils.has_zsh() then
+    -- Use zsh on macOS
+    table.insert(cmd, "zsh")
+    table.insert(cmd, "-c")
+  elseif ShellUtils.has_powershell() then
+    -- Use PowerShell on Windows
+    table.insert(cmd, "powershell")
+    table.insert(cmd, "-Command")
+  else
+    Logger.error("env_stdin_cmd --> Shell not found: powershell, sh, or zsh.")
     return
   end
-  table.remove(splitted, 1)
-  for _, token in ipairs(splitted) do
-    table.insert(cmd, token)
+
+  -- Extract environment variable name (first token)
+  local env_name, cmd_string = cmdstring:match("^(%S+)(.*)$")
+  if not env_name then
+    Logger.error("env_stdin_cmd --> Malformed metatag")
+    return
   end
+
+  -- Append the command string to the command table
+  table.insert(cmd, cmd_string)
+
+  -- Execute the command with the provided contents as stdin
   local res = vim.system(cmd, { stdin = contents, text = true }):wait().stdout
-  if res == nil then
-    vim.notify("env_stdin_cmd --> Command failed: " .. cmd[2] .. ".", vim.log.levels.ERROR)
+
+  if not res then
+    Logger.error("env_stdin_cmd --> Command failed: " .. cmdstring .. ".")
     return
   else
+    -- Save the result to the environment variable
     DB.data.env[env_name] = res
   end
 end

lua/kulala/globals/init.lua

@@ -2,7 +2,7 @@ local FS = require("kulala.utils.fs")
 
 local M = {}
 
-M.VERSION = "3.0.1"
+M.VERSION = "3.0.2"
 M.UI_ID = "kulala://ui"
 M.SCRATCHPAD_ID = "kulala://scratchpad"
 M.HEADERS_FILE = FS.get_plugin_tmp_dir() .. "/headers.txt"