Improve process exec stdin test

tests/process/exec/stdin.luau

@@ -1,19 +1,17 @@
 local process = require("@lune/process")
 
-local IS_WINDOWS = process.os == "windows"
-
--- Windows uses \r\n (CRLF) and unix uses \n (LF)
-
-local echoTrail = if IS_WINDOWS then "\r\n" else "\n"
-local echoMessage = "Hello from child process!"
+local expected = "Hello from child process!"
 
 -- When passing stdin to powershell on windows we must "accept" using the double newline
 
-local result = if IS_WINDOWS
-	then process.exec("powershell", { "echo" }, { stdio = { stdin = echoMessage .. "\n\n" } })
-	else process.exec("xargs", { "echo" }, { stdio = { stdin = echoMessage } })
+local result = if process.os == "windows"
+	then process.exec("powershell", { "echo" }, { stdio = { stdin = expected .. "\n\n" } })
+	else process.exec("xargs", { "echo" }, { stdio = { stdin = expected } })
 
-local resultStdout = if IS_WINDOWS
-	then string.sub(result.stdout, #result.stdout - #echoMessage - 1)
-	else result.stdout
-assert(resultStdout == echoMessage .. echoTrail, "Stdin passing did not return proper output")
+local resultStdout = result.stdout
+resultStdout = string.gsub(resultStdout, "^%s+", "") -- Trim leading whitespace
+resultStdout = string.gsub(resultStdout, "%s+$", "") -- Trim trailing whitespace
+assert(
+	resultStdout == expected,
+	"Stdin passing did not return proper output!" .. `\nExpected: {expected}` .. `\nReceived: {resultStdout}`
+)