crates/ide_assists/src/handlers/unmerge_use.rs

   1 use itertools::Itertools;
   2 use syntax::{
   3     ast::{self, make, VisibilityOwner},
   4     ted::{self, Position},
   5     AstNode, SyntaxKind,
   6 };
   7
   8 use crate::{
   9     assist_context::{AssistContext, Assists},
  10     AssistId, AssistKind,
  11 };
  12
  13 // Assist: unmerge_use
  14 //
  15 // Extracts single use item from use list.
  16 //
  17 // ```
  18 // use std::fmt::{Debug, Display$0};
  19 // ```
  20 // ->
  21 // ```
  22 // use std::fmt::{Debug};
  23 // use std::fmt::Display;
  24 // ```
  25 pub(crate) fn unmerge_use(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
  26     let tree: ast::UseTree = ctx.find_node_at_offset::<ast::UseTree>()?.clone_for_update();
  27
  28     let tree_list = tree.syntax().parent().and_then(ast::UseTreeList::cast)?;
  29     if tree_list.use_trees().count() < 2 {
  30         cov_mark::hit!(skip_single_use_item);
  31         return None;
  32     }
  33
  34     let use_: ast::Use = tree_list.syntax().ancestors().find_map(ast::Use::cast)?;
  35     let path = resolve_full_path(&tree)?;
  36
  37     let old_parent_range = use_.syntax().parent()?.text_range();
  38     let new_parent = use_.syntax().parent()?;
  39
  40     let target = tree.syntax().text_range();
  41     acc.add(
  42         AssistId("unmerge_use", AssistKind::RefactorRewrite),
  43         "Unmerge use",
  44         target,
  45         |builder| {
  46             let new_use = make::use_(
  47                 use_.visibility(),
  48                 make::use_tree(
  49                     path,
  50                     tree.use_tree_list(),
  51                     tree.rename(),
  52                     tree.star_token().is_some(),
  53                 ),
  54             )
  55             .clone_for_update();
  56
  57             tree.remove();
  58             ted::insert(Position::after(use_.syntax()), new_use.syntax());
  59
  60             builder.replace(old_parent_range, new_parent.to_string());
  61         },
  62     )
  63 }
  64
  65 fn resolve_full_path(tree: &ast::UseTree) -> Option<ast::Path> {
  66     let paths = tree
  67         .syntax()
  68         .ancestors()
  69         .take_while(|n| n.kind() != SyntaxKind::USE)
  70         .filter_map(ast::UseTree::cast)
  71         .filter_map(|t| t.path());
  72
  73     let final_path = paths.fold1(|prev, next| make::path_concat(next, prev))?;
  74     if final_path.segment().map_or(false, |it| it.self_token().is_some()) {
  75         final_path.qualifier()
  76     } else {
  77         Some(final_path)
  78     }
  79 }
  80
  81 #[cfg(test)]
  82 mod tests {
  83     use crate::tests::{check_assist, check_assist_not_applicable};
  84
  85     use super::*;
  86
  87     #[test]
  88     fn skip_single_use_item() {
  89         cov_mark::check!(skip_single_use_item);
  90         check_assist_not_applicable(
  91             unmerge_use,
  92             r"
  93 use std::fmt::Debug$0;
  94 ",
  95         );
  96         check_assist_not_applicable(
  97             unmerge_use,
  98             r"
  99 use std::fmt::{Debug$0};
 100 ",
 101         );
 102         check_assist_not_applicable(
 103             unmerge_use,
 104             r"
 105 use std::fmt::Debug as Dbg$0;
 106 ",
 107         );
 108     }
 109
 110     #[test]
 111     fn skip_single_glob_import() {
 112         check_assist_not_applicable(
 113             unmerge_use,
 114             r"
 115 use std::fmt::*$0;
 116 ",
 117         );
 118     }
 119
 120     #[test]
 121     fn unmerge_use_item() {
 122         check_assist(
 123             unmerge_use,
 124             r"
 125 use std::fmt::{Debug, Display$0};
 126 ",
 127             r"
 128 use std::fmt::{Debug};
 129 use std::fmt::Display;
 130 ",
 131         );
 132
 133         check_assist(
 134             unmerge_use,
 135             r"
 136 use std::fmt::{Debug, format$0, Display};
 137 ",
 138             r"
 139 use std::fmt::{Debug, Display};
 140 use std::fmt::format;
 141 ",
 142         );
 143     }
 144
 145     #[test]
 146     fn unmerge_glob_import() {
 147         check_assist(
 148             unmerge_use,
 149             r"
 150 use std::fmt::{*$0, Display};
 151 ",
 152             r"
 153 use std::fmt::{Display};
 154 use std::fmt::*;
 155 ",
 156         );
 157     }
 158
 159     #[test]
 160     fn unmerge_renamed_use_item() {
 161         check_assist(
 162             unmerge_use,
 163             r"
 164 use std::fmt::{Debug, Display as Disp$0};
 165 ",
 166             r"
 167 use std::fmt::{Debug};
 168 use std::fmt::Display as Disp;
 169 ",
 170         );
 171     }
 172
 173     #[test]
 174     fn unmerge_indented_use_item() {
 175         check_assist(
 176             unmerge_use,
 177             r"
 178 mod format {
 179     use std::fmt::{Debug, Display$0 as Disp, format};
 180 }
 181 ",
 182             r"
 183 mod format {
 184     use std::fmt::{Debug, format};
 185     use std::fmt::Display as Disp;
 186 }
 187 ",
 188         );
 189     }
 190
 191     #[test]
 192     fn unmerge_nested_use_item() {
 193         check_assist(
 194             unmerge_use,
 195             r"
 196 use foo::bar::{baz::{qux$0, foobar}, barbaz};
 197 ",
 198             r"
 199 use foo::bar::{baz::{foobar}, barbaz};
 200 use foo::bar::baz::qux;
 201 ",
 202         );
 203         check_assist(
 204             unmerge_use,
 205             r"
 206 use foo::bar::{baz$0::{qux, foobar}, barbaz};
 207 ",
 208             r"
 209 use foo::bar::{barbaz};
 210 use foo::bar::baz::{qux, foobar};
 211 ",
 212         );
 213     }
 214
 215     #[test]
 216     fn unmerge_use_item_with_visibility() {
 217         check_assist(
 218             unmerge_use,
 219             r"
 220 pub use std::fmt::{Debug, Display$0};
 221 ",
 222             r"
 223 pub use std::fmt::{Debug};
 224 pub use std::fmt::Display;
 225 ",
 226         );
 227     }
 228
 229     #[test]
 230     fn unmerge_use_item_on_self() {
 231         check_assist(
 232             unmerge_use,
 233             r"use std::process::{Command, self$0};",
 234             r"use std::process::{Command};
 235 use std::process;",
 236         );
 237     }
 238 }