crates/ra_assists/src/handlers/split_import.rs

   1 use std::iter::successors;
   2
   3 use ra_syntax::{ast, AstNode, T};
   4
   5 use crate::{Assist, AssistCtx, AssistId};
   6
   7 // Assist: split_import
   8 //
   9 // Wraps the tail of import into braces.
  10 //
  11 // ```
  12 // use std::<|>collections::HashMap;
  13 // ```
  14 // ->
  15 // ```
  16 // use std::{collections::HashMap};
  17 // ```
  18 pub(crate) fn split_import(ctx: AssistCtx) -> Option<Assist> {
  19     let colon_colon = ctx.find_token_at_offset(T![::])?;
  20     let path = ast::Path::cast(colon_colon.parent())?.qualifier()?;
  21     let top_path = successors(Some(path.clone()), |it| it.parent_path()).last()?;
  22
  23     let use_tree = top_path.syntax().ancestors().find_map(ast::UseTree::cast)?;
  24
  25     let new_tree = use_tree.split_prefix(&path);
  26     if new_tree == use_tree {
  27         return None;
  28     }
  29     let cursor = ctx.frange.range.start();
  30
  31     ctx.add_assist(AssistId("split_import"), "Split import", |edit| {
  32         edit.target(colon_colon.text_range());
  33         edit.replace_ast(use_tree, new_tree);
  34         edit.set_cursor(cursor);
  35     })
  36 }
  37
  38 #[cfg(test)]
  39 mod tests {
  40     use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
  41
  42     use super::*;
  43
  44     #[test]
  45     fn test_split_import() {
  46         check_assist(
  47             split_import,
  48             "use crate::<|>db::RootDatabase;",
  49             "use crate::<|>{db::RootDatabase};",
  50         )
  51     }
  52
  53     #[test]
  54     fn split_import_works_with_trees() {
  55         check_assist(
  56             split_import,
  57             "use crate:<|>:db::{RootDatabase, FileSymbol}",
  58             "use crate:<|>:{db::{RootDatabase, FileSymbol}}",
  59         )
  60     }
  61
  62     #[test]
  63     fn split_import_target() {
  64         check_assist_target(split_import, "use crate::<|>db::{RootDatabase, FileSymbol}", "::");
  65     }
  66
  67     #[test]
  68     fn issue4044() {
  69         check_assist_not_applicable(split_import, "use crate::<|>:::self;")
  70     }
  71 }