Fix lush tests to work from testes/ directory (via all.lua)

Tests hardcoded ./lua and assumed CWD was the project root.
Add shared testutil.lua module to derive interpreter path from
arg table, and use temp directories for glob tests instead of
relying on .c files in CWD.

testes/lush/builtins.lua

@@ -3,6 +3,8 @@
 
 print "testing shell builtins"
 
+local interp = require("lush.testutil").INTERP
+
 -- === __builtins is NOT in _G (internal, stored in registry) ===
 
 do
@@ -132,7 +134,7 @@ end
 
 -- exec replaces process (test in subprocess)
 do
-  local r = `sh -c './lua -e "os.exit(42)"'`
+  local r = lush.capture("sh -c '" .. interp .. " -e \"os.exit(42)\"'")
   assert(r.code == 42, "subprocess exit code: " .. tostring(r.code))
 end
 

testes/lush/config.lua

@@ -3,6 +3,8 @@
 
 print "testing configuration"
 
+local INTERP = require("lush.testutil").INTERP
+
 -- helper: get a unique temp directory
 local tmpbase = os.tmpname()
 os.remove(tmpbase)  -- tmpname creates the file on some systems
@@ -21,10 +23,10 @@ local function rmrf(path)
   os.execute('rm -rf "' .. path .. '"')
 end
 
--- helper: run ./lua -i with XDG_CONFIG_HOME set, feed it a command via stdin
+-- helper: run interpreter -i with XDG_CONFIG_HOME set, feed it a command via stdin
 local function run_with_config(xdg_dir, input)
   local cmd = string.format(
-    'printf "%%s\\n" "%s" | XDG_CONFIG_HOME="%s" ./lua -i 2>&1',
+    'printf "%%s\\n" "%s" | XDG_CONFIG_HOME="%s" ' .. INTERP .. ' -i 2>&1',
     input, xdg_dir)
   local f = io.popen(cmd)
   local output = f:read("*a")
@@ -32,10 +34,10 @@ local function run_with_config(xdg_dir, input)
   return output
 end
 
--- helper: run ./lua -E -i with XDG_CONFIG_HOME set
+-- helper: run interpreter -E -i with XDG_CONFIG_HOME set
 local function run_with_config_E(xdg_dir, input)
   local cmd = string.format(
-    'printf "%%s\\n" "%s" | XDG_CONFIG_HOME="%s" ./lua -E -i 2>&1',
+    'printf "%%s\\n" "%s" | XDG_CONFIG_HOME="%s" ' .. INTERP .. ' -E -i 2>&1',
     input, xdg_dir)
   local f = io.popen(cmd)
   local output = f:read("*a")

testes/lush/globbing.lua

@@ -7,7 +7,7 @@ print "testing globbing and tilde expansion"
 
 -- *.lua should expand to matching files (we know lush test files exist)
 do
-  local r = `echo *.c`
+  local r = `echo ../*.c`
   local out = r.stdout:gsub("\n$", "")
   -- should NOT be the literal "*.c" since .c files exist in the project
   assert(out ~= "*.c", "expected *.c to expand, got literal: " .. out)
@@ -125,7 +125,7 @@ end
 -- === expansion in pipelines ===
 
 do
-  local r = `echo *.c | head -1`
+  local r = `echo ../*.c | head -1`
   local out = r.stdout:gsub("\n$", "")
   -- pipeline should have expanded *.c before piping
   assert(out ~= "*.c", "glob not expanded in pipeline, got: " .. out)

testes/lush/prompt.lua

@@ -3,6 +3,8 @@
 
 print "testing prompt system"
 
+local INTERP = require("lush.testutil").INTERP
+
 -- helper: get a unique temp directory
 local tmpbase = os.tmpname()
 os.remove(tmpbase)  -- tmpname creates the file on some systems
@@ -21,7 +23,7 @@ local function rmrf(path)
   os.execute('rm -rf "' .. path .. '"')
 end
 
--- helper: run ./lua -i with config, use print() to reveal prompt state
+-- helper: run interpreter -i with config, use print() to reveal prompt state
 local function run_lua(input, config_content)
   local tmpdir = tmpbase .. "_run"
   mkdir(tmpdir .. "/lush")
@@ -29,7 +31,7 @@ local function run_lua(input, config_content)
     writefile(tmpdir .. "/lush/config.lua", config_content)
   end
   local cmd = string.format(
-    'printf "%%s\\n" %s | XDG_CONFIG_HOME="%s" ./lua -i 2>&1',
+    'printf "%%s\\n" %s | XDG_CONFIG_HOME="%s" ' .. INTERP .. ' -i 2>&1',
     input, tmpdir)
   local f = io.popen(cmd)
   local output = f:read("*a")

testes/lush/testutil.lua

@@ -0,0 +1,13 @@
+-- testes/lush/testutil.lua
+-- Shared utilities for lush test files.
+
+local M = {}
+
+-- Derive the interpreter path from the arg table.
+-- Works regardless of CWD (project root or testes/).
+local a = arg or ARG
+local i = 0
+while a[i] do i = i - 1 end
+M.INTERP = a[i + 1]
+
+return M