aboutsummaryrefslogtreecommitdiff
path: root/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
blob: 48433feb9e98cfb07daf6c0c6cd7b90a63d9bc46 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
use hir::{EnumVariant, Module, ModuleDef, Name};
use ide_db::base_db::FileId;
use ide_db::{defs::Definition, search::Reference, RootDatabase};
use itertools::Itertools;
use rustc_hash::FxHashSet;
use syntax::{
    algo::find_node_at_offset,
    ast::{self, edit::IndentLevel, ArgListOwner, AstNode, NameOwner, VisibilityOwner},
    SourceFile, TextRange, TextSize,
};

use crate::{
    assist_context::AssistBuilder,
    utils::{insert_use, mod_path_to_ast, ImportScope},
    AssistContext, AssistId, AssistKind, Assists,
};

// Assist: extract_struct_from_enum_variant
//
// Extracts a struct from enum variant.
//
// ```
// enum A { <|>One(u32, u32) }
// ```
// ->
// ```
// struct One(pub u32, pub u32);
//
// enum A { One(One) }
// ```
pub(crate) fn extract_struct_from_enum_variant(
    acc: &mut Assists,
    ctx: &AssistContext,
) -> Option<()> {
    let variant = ctx.find_node_at_offset::<ast::Variant>()?;
    let field_list = match variant.kind() {
        ast::StructKind::Tuple(field_list) => field_list,
        _ => return None,
    };
    let variant_name = variant.name()?.to_string();
    let variant_hir = ctx.sema.to_def(&variant)?;
    if existing_struct_def(ctx.db(), &variant_name, &variant_hir) {
        return None;
    }
    let enum_ast = variant.parent_enum();
    let visibility = enum_ast.visibility();
    let enum_hir = ctx.sema.to_def(&enum_ast)?;
    let variant_hir_name = variant_hir.name(ctx.db());
    let enum_module_def = ModuleDef::from(enum_hir);
    let current_module = enum_hir.module(ctx.db());
    let target = variant.syntax().text_range();
    acc.add(
        AssistId("extract_struct_from_enum_variant", AssistKind::RefactorRewrite),
        "Extract struct from enum variant",
        target,
        |builder| {
            let definition = Definition::ModuleDef(ModuleDef::EnumVariant(variant_hir));
            let res = definition.usages(&ctx.sema).all();
            let start_offset = variant.parent_enum().syntax().text_range().start();
            let mut visited_modules_set = FxHashSet::default();
            visited_modules_set.insert(current_module);
            for reference in res {
                let source_file = ctx.sema.parse(reference.file_range.file_id);
                update_reference(
                    ctx,
                    builder,
                    reference,
                    &source_file,
                    &enum_module_def,
                    &variant_hir_name,
                    &mut visited_modules_set,
                );
            }
            extract_struct_def(
                builder,
                &enum_ast,
                &variant_name,
                &field_list.to_string(),
                start_offset,
                ctx.frange.file_id,
                &visibility,
            );
            let list_range = field_list.syntax().text_range();
            update_variant(builder, &variant_name, ctx.frange.file_id, list_range);
        },
    )
}

fn existing_struct_def(db: &RootDatabase, variant_name: &str, variant: &EnumVariant) -> bool {
    variant
        .parent_enum(db)
        .module(db)
        .scope(db, None)
        .into_iter()
        .any(|(name, _)| name.to_string() == variant_name)
}

#[allow(dead_code)]
fn insert_import(
    ctx: &AssistContext,
    builder: &mut AssistBuilder,
    path: &ast::PathExpr,
    module: &Module,
    enum_module_def: &ModuleDef,
    variant_hir_name: &Name,
) -> Option<()> {
    let db = ctx.db();
    let mod_path = module.find_use_path(db, enum_module_def.clone());
    if let Some(mut mod_path) = mod_path {
        mod_path.segments.pop();
        mod_path.segments.push(variant_hir_name.clone());
        let scope = ImportScope::find_insert_use_container(path.syntax(), ctx)?;
        let syntax = scope.as_syntax_node();

        let new_syntax =
            insert_use(&scope, mod_path_to_ast(&mod_path), ctx.config.insert_use.merge);
        // FIXME: this will currently panic as multiple imports will have overlapping text ranges
        builder.replace(syntax.text_range(), new_syntax.to_string())
    }
    Some(())
}

// FIXME: this should use strongly-typed `make`, rather than string manipulation.
fn extract_struct_def(
    builder: &mut AssistBuilder,
    enum_: &ast::Enum,
    variant_name: &str,
    variant_list: &str,
    start_offset: TextSize,
    file_id: FileId,
    visibility: &Option<ast::Visibility>,
) -> Option<()> {
    let visibility_string = if let Some(visibility) = visibility {
        format!("{} ", visibility.to_string())
    } else {
        "".to_string()
    };
    let indent = IndentLevel::from_node(enum_.syntax());
    let struct_def = format!(
        r#"{}struct {}{};

{}"#,
        visibility_string,
        variant_name,
        list_with_visibility(variant_list),
        indent
    );
    builder.edit_file(file_id);
    builder.insert(start_offset, struct_def);
    Some(())
}

fn update_variant(
    builder: &mut AssistBuilder,
    variant_name: &str,
    file_id: FileId,
    list_range: TextRange,
) -> Option<()> {
    let inside_variant_range = TextRange::new(
        list_range.start().checked_add(TextSize::from(1))?,
        list_range.end().checked_sub(TextSize::from(1))?,
    );
    builder.edit_file(file_id);
    builder.replace(inside_variant_range, variant_name);
    Some(())
}

fn update_reference(
    ctx: &AssistContext,
    builder: &mut AssistBuilder,
    reference: Reference,
    source_file: &SourceFile,
    _enum_module_def: &ModuleDef,
    _variant_hir_name: &Name,
    _visited_modules_set: &mut FxHashSet<Module>,
) -> Option<()> {
    let path_expr: ast::PathExpr = find_node_at_offset::<ast::PathExpr>(
        source_file.syntax(),
        reference.file_range.range.start(),
    )?;
    let call = path_expr.syntax().parent().and_then(ast::CallExpr::cast)?;
    let list = call.arg_list()?;
    let segment = path_expr.path()?.segment()?;
    let _module = ctx.sema.scope(&path_expr.syntax()).module()?;
    let list_range = list.syntax().text_range();
    let inside_list_range = TextRange::new(
        list_range.start().checked_add(TextSize::from(1))?,
        list_range.end().checked_sub(TextSize::from(1))?,
    );
    builder.edit_file(reference.file_range.file_id);
    /* FIXME: this most likely requires AST-based editing, see `insert_import`
    if !visited_modules_set.contains(&module) {
        if insert_import(ctx, builder, &path_expr, &module, enum_module_def, variant_hir_name)
            .is_some()
        {
            visited_modules_set.insert(module);
        }
    }
    */
    builder.replace(inside_list_range, format!("{}{}", segment, list));
    Some(())
}

fn list_with_visibility(list: &str) -> String {
    list.split(',')
        .map(|part| {
            let index = if part.chars().next().unwrap() == '(' { 1usize } else { 0 };
            let mut mod_part = part.trim().to_string();
            mod_part.insert_str(index, "pub ");
            mod_part
        })
        .join(", ")
}

#[cfg(test)]
mod tests {
    use crate::{
        tests::{check_assist, check_assist_not_applicable},
        utils::FamousDefs,
    };

    use super::*;

    #[test]
    fn test_extract_struct_several_fields() {
        check_assist(
            extract_struct_from_enum_variant,
            "enum A { <|>One(u32, u32) }",
            r#"struct One(pub u32, pub u32);

enum A { One(One) }"#,
        );
    }

    #[test]
    fn test_extract_struct_one_field() {
        check_assist(
            extract_struct_from_enum_variant,
            "enum A { <|>One(u32) }",
            r#"struct One(pub u32);

enum A { One(One) }"#,
        );
    }

    #[test]
    fn test_extract_struct_pub_visibility() {
        check_assist(
            extract_struct_from_enum_variant,
            "pub enum A { <|>One(u32, u32) }",
            r#"pub struct One(pub u32, pub u32);

pub enum A { One(One) }"#,
        );
    }

    #[test]
    #[ignore] // FIXME: this currently panics if `insert_import` is used
    fn test_extract_struct_with_complex_imports() {
        check_assist(
            extract_struct_from_enum_variant,
            r#"mod my_mod {
    fn another_fn() {
        let m = my_other_mod::MyEnum::MyField(1, 1);
    }

    pub mod my_other_mod {
        fn another_fn() {
            let m = MyEnum::MyField(1, 1);
        }

        pub enum MyEnum {
            <|>MyField(u8, u8),
        }
    }
}

fn another_fn() {
    let m = my_mod::my_other_mod::MyEnum::MyField(1, 1);
}"#,
            r#"use my_mod::my_other_mod::MyField;

mod my_mod {
    use my_other_mod::MyField;

    fn another_fn() {
        let m = my_other_mod::MyEnum::MyField(MyField(1, 1));
    }

    pub mod my_other_mod {
        fn another_fn() {
            let m = MyEnum::MyField(MyField(1, 1));
        }

        pub struct MyField(pub u8, pub u8);

        pub enum MyEnum {
            MyField(MyField),
        }
    }
}

fn another_fn() {
    let m = my_mod::my_other_mod::MyEnum::MyField(MyField(1, 1));
}"#,
        );
    }

    fn check_not_applicable(ra_fixture: &str) {
        let fixture =
            format!("//- /main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
        check_assist_not_applicable(extract_struct_from_enum_variant, &fixture)
    }

    #[test]
    fn test_extract_enum_not_applicable_for_element_with_no_fields() {
        check_not_applicable("enum A { <|>One }");
    }

    #[test]
    fn test_extract_enum_not_applicable_if_struct_exists() {
        check_not_applicable(
            r#"struct One;
        enum A { <|>One(u8) }"#,
        );
    }
}