feat(rustc): do not require a main function + support 2024 edition (#225

)

Co-authored-by: saying121 <saying121@example.com>
Co-authored-by: Marc Jakobi <mrcjkb89@outlook.com>

CHANGELOG.md

@@ -6,6 +6,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- Rustc: Do not require a main function,
+  and support the 2024 edition
+  via `unstable-options`.
+
 ## [4.6.0] - 2024-02-07
 
 ### Added
@@ -93,7 +101,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   Used by default in Neovim >= 0.10.
 - LSP: `:RustLsp testables` command, which is equivalent
   to `:RustLsp runnables`, but filters the runnables for tests only,
-  
+
 > [!IMPORTANT]
 >
 > In Neovim < 0.10, `'background'` executor blocks the UI while running tests.
@@ -107,7 +115,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   and achieve an experience similar to Rust Playground.
   (currently requires a nightly compiler).
   Thanks [saying121](https://github.com/saying121)!
-- Config: `tools.rustc_unpretty` arguments for `rustc`.
+- Config: `tools.rustc` arguments for `rustc`.
 
 ### Changed
 

lua/rustaceanvim/commands/rustc_unpretty.lua

@@ -110,7 +110,7 @@ function M.rustc_unpretty(level)
   local pos = { math.max(cursor[1] - 1, 0), cursor[2] }
 
   local cline = api.nvim_get_current_line()
-  if not string.find(cline, 'fn%s*') then
+  if not string.find(cline, 'fn%s+') then
     local temp = vim.fn.searchpos('fn ', 'bcn', vim.fn.line('w0'))
     pos = { math.max(temp[1] - 1, 0), temp[2] }
   end
@@ -129,16 +129,18 @@ function M.rustc_unpretty(level)
   end
   text = table.concat(b, '\n')
 
-  -- rustc need a main function for `-Z unpretty`
-  if not string.find(text, 'fn%s*main') then
-    text = text .. 'fn main() {}'
-  end
-
-  compat.system(
-    { rustc, '--edition', config.tools.rustc.edition, '-Z', 'unpretty=' .. level, '-' },
-    { stdin = text },
-    vim.schedule_wrap(handler)
-  )
+  compat.system({
+    rustc,
+    '--crate-type',
+    'lib',
+    '--edition',
+    config.tools.rustc.edition,
+    '-Z',
+    'unstable-options',
+    '-Z',
+    'unpretty=' .. level,
+    '-',
+  }, { stdin = text }, vim.schedule_wrap(handler))
 end
 
 return M