feat: completions for :RustLsp subcommands' arguments

Author: Marc Jakobi

CHANGELOG.md

@@ -5,12 +5,19 @@ 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
+- Completions for `:RustLsp` subcommands' arguments.
+
 ## [3.1.1] - 2023-10-28
+
 ### Fixed
 - Remove accidental use of Neovim nightly API (`dap`, `crateGraph`, `explainError`) [[#26](https://github.com/mrcjkb/rustaceanvim/issues/26)].
 - Add static type checking for Neovim stable API.
 
 ## [3.1.0] - 2023-10-28
+
 ### Added
 - `:RustLsp explainError` command, uses `rustc --explain` on error diagnostics with
   an error code.
@@ -20,11 +27,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Health check got stuck if `lldb-vscode` was installed.
 
 ## [3.0.4] - 2023-10-25
+
 ### Fixed
 - Allow `:RustLsp hover range` to accept a range.
 - Fix `:RustLsp crateGraph` passing arguments as list.
 
 ## [3.0.3] - 2023-10-25
+
 ### Fixed
 - Potential attempt to index `nil` upvalue when sending `workspace/didChangeWorkspaceFolders`
   to LSP server [[#22](https://github.com/mrcjkb/rustaceanvim/issues/22)].

lua/rustaceanvim/commands/init.lua

@@ -125,14 +125,21 @@ function M.create_rust_lsp_command()
     desc = 'Interacts with the rust-analyzer LSP client',
     complete = function(arg_lead, cmdline, _)
       local commands = vim.tbl_keys(command_tbl)
+      local match_start = '^' .. rust_lsp_cmd_name
       -- special case: crateGraph comes with graphviz backend completions
-      if cmdline:match('^' .. rust_lsp_cmd_name .. ' cr%s+%w*$') then
-        local backends = config.tools.crate_graph.enabled_graphviz_backends or {}
-        return vim.tbl_map(function(backend)
-          return 'crateGraph ' .. backend
-        end, backends)
+      if cmdline:match(match_start .. ' debuggables%s+%w*$') or cmdline:match(match_start .. ' runnables%s+%w*$') then
+        return { 'last' }
       end
-      if cmdline:match('^' .. rust_lsp_cmd_name .. '%s+%w*$') then
+      if cmdline:match(match_start .. ' hover%s+%w*$') then
+        return { 'action', 'range' }
+      end
+      if cmdline:match(match_start .. ' moveItem%s+%w*$') then
+        return { 'up', 'down' }
+      end
+      if cmdline:match(match_start .. ' crateGraph%s+%w*$') then
+        return config.tools.crate_graph.enabled_graphviz_backends or {}
+      end
+      if cmdline:match(match_start .. '%s+%w*$') then
         return vim
           .iter(commands)
           :filter(function(command)