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::{AssistContext, AssistId, Assists};
   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(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
  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
  30     let target = colon_colon.text_range();
  31     acc.add(AssistId("split_import"), "Split import", target, |edit| {
  32         edit.replace_ast(use_tree, new_tree);
  33     })
  34 }
  35
  36 #[cfg(test)]
  37 mod tests {
  38     use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
  39
  40     use super::*;
  41
  42     #[test]
  43     fn test_split_import() {
  44         check_assist(
  45             split_import,
  46             "use crate::<|>db::RootDatabase;",
  47             "use crate::{db::RootDatabase};",
  48         )
  49     }
  50
  51     #[test]
  52     fn split_import_works_with_trees() {
  53         check_assist(
  54             split_import,
  55             "use crate:<|>:db::{RootDatabase, FileSymbol}",
  56             "use crate::{db::{RootDatabase, FileSymbol}}",
  57         )
  58     }
  59
  60     #[test]
  61     fn split_import_target() {
  62         check_assist_target(split_import, "use crate::<|>db::{RootDatabase, FileSymbol}", "::");
  63     }
  64
  65     #[test]
  66     fn issue4044() {
  67         check_assist_not_applicable(split_import, "use crate::<|>:::self;")
  68     }
  69
  70     #[test]
  71     fn test_empty_use() {
  72         check_assist_not_applicable(
  73             split_import,
  74             r"
  75 use std::<|>
  76 fn main() {}",
  77         );
  78     }
  79 }