crates/ide_assists/src/handlers/unmerge_use.rs

   1 use ast::make;
   2 use itertools::Itertools;
   3 use syntax::{
   4     ast::{self, VisibilityOwner},
   5     ted::{self, Position},
   6     AstNode, SyntaxKind,
   7 };
   8
   9 use crate::{
  10     assist_context::{AssistContext, Assists},
  11     AssistId, AssistKind,
  12 };
  13
  14 // Assist: unmerge_use
  15 //
  16 // Extracts single use item from use list.
  17 //
  18 // ```
  19 // use std::fmt::{Debug, Display$0};
  20 // ```
  21 // ->
  22 // ```
  23 // use std::fmt::{Debug};
  24 // use std::fmt::Display;
  25 // ```
  26 pub(crate) fn unmerge_use(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
  27     let tree: ast::UseTree = ctx.find_node_at_offset::<ast::UseTree>()?.clone_for_update();
  28
  29     let tree_list = tree.syntax().parent().and_then(ast::UseTreeList::cast)?;
  30     if tree_list.use_trees().count() < 2 {
  31         cov_mark::hit!(skip_single_use_item);
  32         return None;
  33     }
  34
  35     let use_: ast::Use = tree_list.syntax().ancestors().find_map(ast::Use::cast)?;
  36     let path = resolve_full_path(&tree)?;
  37
  38     let old_parent_range = use_.syntax().parent()?.text_range();
  39     let new_parent = use_.syntax().parent()?;
  40
  41     let target = tree.syntax().text_range();
  42     acc.add(
  43         AssistId("unmerge_use", AssistKind::RefactorRewrite),
  44         "Unmerge use",
  45         target,
  46         |builder| {
  47             let new_use = make::use_(
  48                 use_.visibility(),
  49                 make::use_tree(
  50                     path,
  51                     tree.use_tree_list(),
  52                     tree.rename(),
  53                     tree.star_token().is_some(),
  54                 ),
  55             )
  56             .clone_for_update();
  57
  58             tree.remove();
  59             ted::insert(Position::after(use_.syntax()), new_use.syntax());
  60
  61             builder.replace(old_parent_range, new_parent.to_string());
  62         },
  63     )
  64 }
  65
  66 fn resolve_full_path(tree: &ast::UseTree) -> Option<ast::Path> {
  67     let paths = tree
  68         .syntax()
  69         .ancestors()
  70         .take_while(|n| n.kind() != SyntaxKind::USE)
  71         .filter_map(ast::UseTree::cast)
  72         .filter_map(|t| t.path());
  73
  74     let final_path = paths.fold1(|prev, next| make::path_concat(next, prev))?;
  75     if final_path.segment().map_or(false, |it| it.self_token().is_some()) {
  76         final_path.qualifier()
  77     } else {
  78         Some(final_path)
  79     }
  80 }
  81
  82 #[cfg(test)]
  83 mod tests {
  84     use crate::tests::{check_assist, check_assist_not_applicable};
  85
  86     use super::*;
  87
  88     #[test]
  89     fn skip_single_use_item() {
  90         cov_mark::check!(skip_single_use_item);
  91         check_assist_not_applicable(
  92             unmerge_use,
  93             r"
  94 use std::fmt::Debug$0;
  95 ",
  96         );
  97         check_assist_not_applicable(
  98             unmerge_use,
  99             r"
 100 use std::fmt::{Debug$0};
 101 ",
 102         );
 103         check_assist_not_applicable(
 104             unmerge_use,
 105             r"
 106 use std::fmt::Debug as Dbg$0;
 107 ",
 108         );
 109     }
 110
 111     #[test]
 112     fn skip_single_glob_import() {
 113         check_assist_not_applicable(
 114             unmerge_use,
 115             r"
 116 use std::fmt::*$0;
 117 ",
 118         );
 119     }
 120
 121     #[test]
 122     fn unmerge_use_item() {
 123         check_assist(
 124             unmerge_use,
 125             r"
 126 use std::fmt::{Debug, Display$0};
 127 ",
 128             r"
 129 use std::fmt::{Debug};
 130 use std::fmt::Display;
 131 ",
 132         );
 133
 134         check_assist(
 135             unmerge_use,
 136             r"
 137 use std::fmt::{Debug, format$0, Display};
 138 ",
 139             r"
 140 use std::fmt::{Debug, Display};
 141 use std::fmt::format;
 142 ",
 143         );
 144     }
 145
 146     #[test]
 147     fn unmerge_glob_import() {
 148         check_assist(
 149             unmerge_use,
 150             r"
 151 use std::fmt::{*$0, Display};
 152 ",
 153             r"
 154 use std::fmt::{Display};
 155 use std::fmt::*;
 156 ",
 157         );
 158     }
 159
 160     #[test]
 161     fn unmerge_renamed_use_item() {
 162         check_assist(
 163             unmerge_use,
 164             r"
 165 use std::fmt::{Debug, Display as Disp$0};
 166 ",
 167             r"
 168 use std::fmt::{Debug};
 169 use std::fmt::Display as Disp;
 170 ",
 171         );
 172     }
 173
 174     #[test]
 175     fn unmerge_indented_use_item() {
 176         check_assist(
 177             unmerge_use,
 178             r"
 179 mod format {
 180     use std::fmt::{Debug, Display$0 as Disp, format};
 181 }
 182 ",
 183             r"
 184 mod format {
 185     use std::fmt::{Debug, format};
 186     use std::fmt::Display as Disp;
 187 }
 188 ",
 189         );
 190     }
 191
 192     #[test]
 193     fn unmerge_nested_use_item() {
 194         check_assist(
 195             unmerge_use,
 196             r"
 197 use foo::bar::{baz::{qux$0, foobar}, barbaz};
 198 ",
 199             r"
 200 use foo::bar::{baz::{foobar}, barbaz};
 201 use foo::bar::baz::qux;
 202 ",
 203         );
 204         check_assist(
 205             unmerge_use,
 206             r"
 207 use foo::bar::{baz$0::{qux, foobar}, barbaz};
 208 ",
 209             r"
 210 use foo::bar::{barbaz};
 211 use foo::bar::baz::{qux, foobar};
 212 ",
 213         );
 214     }
 215
 216     #[test]
 217     fn unmerge_use_item_with_visibility() {
 218         check_assist(
 219             unmerge_use,
 220             r"
 221 pub use std::fmt::{Debug, Display$0};
 222 ",
 223             r"
 224 pub use std::fmt::{Debug};
 225 pub use std::fmt::Display;
 226 ",
 227         );
 228     }
 229
 230     #[test]
 231     fn unmerge_use_item_on_self() {
 232         check_assist(
 233             unmerge_use,
 234             r"use std::process::{Command, self$0};",
 235             r"use std::process::{Command};
 236 use std::process;",
 237         );
 238     }
 239 }