crates/ide_assists/src/handlers/split_import.rs

   1 use syntax::{ast, AstNode, T};
   2
   3 use crate::{AssistContext, AssistId, AssistKind, Assists};
   4
   5 // Assist: split_import
   6 //
   7 // Wraps the tail of import into braces.
   8 //
   9 // ```
  10 // use std::$0collections::HashMap;
  11 // ```
  12 // ->
  13 // ```
  14 // use std::{collections::HashMap};
  15 // ```
  16 pub(crate) fn split_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
  17     let colon_colon = ctx.find_token_syntax_at_offset(T![::])?;
  18     let path = ast::Path::cast(colon_colon.parent()?)?.qualifier()?;
  19
  20     let use_tree = path.top_path().syntax().ancestors().find_map(ast::UseTree::cast)?;
  21
  22     let new_tree = use_tree.split_prefix(&path);
  23     if new_tree == use_tree {
  24         return None;
  25     }
  26
  27     let target = colon_colon.text_range();
  28     acc.add(AssistId("split_import", AssistKind::RefactorRewrite), "Split import", target, |edit| {
  29         edit.replace_ast(use_tree, new_tree);
  30     })
  31 }
  32
  33 #[cfg(test)]
  34 mod tests {
  35     use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
  36
  37     use super::*;
  38
  39     #[test]
  40     fn test_split_import() {
  41         check_assist(
  42             split_import,
  43             "use crate::$0db::RootDatabase;",
  44             "use crate::{db::RootDatabase};",
  45         )
  46     }
  47
  48     #[test]
  49     fn split_import_works_with_trees() {
  50         check_assist(
  51             split_import,
  52             "use crate:$0:db::{RootDatabase, FileSymbol}",
  53             "use crate::{db::{RootDatabase, FileSymbol}}",
  54         )
  55     }
  56
  57     #[test]
  58     fn split_import_target() {
  59         check_assist_target(split_import, "use crate::$0db::{RootDatabase, FileSymbol}", "::");
  60     }
  61
  62     #[test]
  63     fn issue4044() {
  64         check_assist_not_applicable(split_import, "use crate::$0:::self;")
  65     }
  66
  67     #[test]
  68     fn test_empty_use() {
  69         check_assist_not_applicable(
  70             split_import,
  71             r"
  72 use std::$0
  73 fn main() {}",
  74         );
  75     }
  76 }