From 753897222ab8b02101d483d3d88384b6a992771d Mon Sep 17 00:00:00 2001
From: Filip Tibell <filip.tibell@gmail.com>
Date: Thu, 18 Apr 2024 22:10:08 +0200
Subject: [PATCH] Implement stdio.readToEnd API

---
 src/lune/builtins/stdio/mod.rs | 18 +++++++++++++++++-
 types/stdio.luau               | 17 +++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/lune/builtins/stdio/mod.rs b/src/lune/builtins/stdio/mod.rs
index 14927f2..f851bc7 100644
--- a/src/lune/builtins/stdio/mod.rs
+++ b/src/lune/builtins/stdio/mod.rs
@@ -2,7 +2,7 @@ use mlua::prelude::*;
 
 use dialoguer::{theme::ColorfulTheme, Confirm, Input, MultiSelect, Select};
 use mlua_luau_scheduler::LuaSpawnExt;
-use tokio::io::{self, AsyncWriteExt};
+use tokio::io::{self, AsyncReadExt, AsyncWriteExt};
 
 use crate::lune::util::{
     formatting::{
@@ -21,6 +21,7 @@ pub fn create(lua: &Lua) -> LuaResult<LuaTable<'_>> {
         .with_function("format", stdio_format)?
         .with_async_function("write", stdio_write)?
         .with_async_function("ewrite", stdio_ewrite)?
+        .with_async_function("readToEnd", stdio_read_to_end)?
         .with_async_function("prompt", stdio_prompt)?
         .build_readonly()
 }
@@ -53,6 +54,21 @@ async fn stdio_ewrite(_: &Lua, s: LuaString<'_>) -> LuaResult<()> {
     Ok(())
 }
 
+/*
+    FUTURE: Figure out how to expose some kind of "readLine" function using a buffered reader.
+
+    This is a bit tricky since we would want to be able to use **both** readLine and readToEnd
+    in the same script, doing something like readLine, readLine, readToEnd from lua, and
+    having that capture the first two lines and then read the rest of the input.
+*/
+
+async fn stdio_read_to_end(lua: &Lua, _: ()) -> LuaResult<LuaString> {
+    let mut input = Vec::new();
+    let mut stdin = io::stdin();
+    stdin.read_to_end(&mut input).await?;
+    lua.create_string(&input)
+}
+
 async fn stdio_prompt(lua: &Lua, options: PromptOptions) -> LuaResult<PromptResult> {
     lua.spawn_blocking(move || prompt(options))
         .await
diff --git a/types/stdio.luau b/types/stdio.luau
index 3c5198e..70a73e0 100644
--- a/types/stdio.luau
+++ b/types/stdio.luau
@@ -58,6 +58,11 @@ end
 	stdio.write("World! ")
 	stdio.write("All on the same line")
 	stdio.ewrite("\nAnd some error text, too")
+
+	-- Reading from stdin, either line-by-line or the entire input
+	local firstLine = stdio.readLine()
+	local secondLine = stdio.readLine()
+	local remaining = stdio.readToEnd()
 	```
 ]=]
 local stdio = {}
@@ -143,4 +148,16 @@ function stdio.write(s: string) end
 ]=]
 function stdio.ewrite(s: string) end
 
+--[=[
+    @within Stdio
+    @tag must_use
+
+    Reads the entire input from stdin.
+
+    @return The input from stdin
+]=]
+function stdio.readToEnd(): string
+	return nil :: any
+end
+
 return stdio