crates/ide_completion/src/context.rs

   1 //! See `CompletionContext` structure.
   2
   3 use hir::{Local, ScopeDef, Semantics, SemanticsScope, Type};
   4 use ide_db::base_db::{FilePosition, SourceDatabase};
   5 use ide_db::{call_info::ActiveParameter, RootDatabase};
   6 use syntax::{
   7     algo::find_node_at_offset, ast, match_ast, AstNode, NodeOrToken, SyntaxKind::*, SyntaxNode,
   8     SyntaxToken, TextRange, TextSize,
   9 };
  10
  11 use text_edit::Indel;
  12
  13 use crate::{
  14     patterns::{
  15         fn_is_prev, for_is_prev2, has_bind_pat_parent, has_block_expr_parent,
  16         has_field_list_parent, has_impl_as_prev_sibling, has_impl_parent,
  17         has_item_list_or_source_file_parent, has_ref_parent, has_trait_as_prev_sibling,
  18         has_trait_parent, if_is_prev, inside_impl_trait_block, is_in_loop_body, is_match_arm,
  19         unsafe_is_prev,
  20     },
  21     CompletionConfig,
  22 };
  23
  24 /// `CompletionContext` is created early during completion to figure out, where
  25 /// exactly is the cursor, syntax-wise.
  26 #[derive(Debug)]
  27 pub(crate) struct CompletionContext<'a> {
  28     pub(super) sema: Semantics<'a, RootDatabase>,
  29     pub(super) scope: SemanticsScope<'a>,
  30     pub(super) db: &'a RootDatabase,
  31     pub(super) config: &'a CompletionConfig,
  32     pub(super) position: FilePosition,
  33     /// The token before the cursor, in the original file.
  34     pub(super) original_token: SyntaxToken,
  35     /// The token before the cursor, in the macro-expanded file.
  36     pub(super) token: SyntaxToken,
  37     pub(super) krate: Option<hir::Crate>,
  38     pub(super) expected_name: Option<String>,
  39     pub(super) expected_type: Option<Type>,
  40     pub(super) name_ref_syntax: Option<ast::NameRef>,
  41     pub(super) function_syntax: Option<ast::Fn>,
  42     pub(super) use_item_syntax: Option<ast::Use>,
  43     pub(super) record_lit_syntax: Option<ast::RecordExpr>,
  44     pub(super) record_pat_syntax: Option<ast::RecordPat>,
  45     pub(super) record_field_syntax: Option<ast::RecordExprField>,
  46     pub(super) impl_def: Option<ast::Impl>,
  47     /// FIXME: `ActiveParameter` is string-based, which is very very wrong
  48     pub(super) active_parameter: Option<ActiveParameter>,
  49     pub(super) is_param: bool,
  50     /// If a name-binding or reference to a const in a pattern.
  51     /// Irrefutable patterns (like let) are excluded.
  52     pub(super) is_pat_binding_or_const: bool,
  53     pub(super) is_irrefutable_pat_binding: bool,
  54     /// A single-indent path, like `foo`. `::foo` should not be considered a trivial path.
  55     pub(super) is_trivial_path: bool,
  56     /// If not a trivial path, the prefix (qualifier).
  57     pub(super) path_qual: Option<ast::Path>,
  58     pub(super) after_if: bool,
  59     /// `true` if we are a statement or a last expr in the block.
  60     pub(super) can_be_stmt: bool,
  61     /// `true` if we expect an expression at the cursor position.
  62     pub(super) is_expr: bool,
  63     /// Something is typed at the "top" level, in module or impl/trait.
  64     pub(super) is_new_item: bool,
  65     /// The receiver if this is a field or method access, i.e. writing something.$0
  66     pub(super) dot_receiver: Option<ast::Expr>,
  67     pub(super) dot_receiver_is_ambiguous_float_literal: bool,
  68     /// If this is a call (method or function) in particular, i.e. the () are already there.
  69     pub(super) is_call: bool,
  70     /// Like `is_call`, but for tuple patterns.
  71     pub(super) is_pattern_call: bool,
  72     /// If this is a macro call, i.e. the () are already there.
  73     pub(super) is_macro_call: bool,
  74     pub(super) is_path_type: bool,
  75     pub(super) has_type_args: bool,
  76     pub(super) attribute_under_caret: Option<ast::Attr>,
  77     pub(super) mod_declaration_under_caret: Option<ast::Module>,
  78     pub(super) unsafe_is_prev: bool,
  79     pub(super) if_is_prev: bool,
  80     pub(super) block_expr_parent: bool,
  81     pub(super) bind_pat_parent: bool,
  82     pub(super) ref_pat_parent: bool,
  83     pub(super) in_loop_body: bool,
  84     pub(super) has_trait_parent: bool,
  85     pub(super) has_impl_parent: bool,
  86     pub(super) inside_impl_trait_block: bool,
  87     pub(super) has_field_list_parent: bool,
  88     pub(super) trait_as_prev_sibling: bool,
  89     pub(super) impl_as_prev_sibling: bool,
  90     pub(super) is_match_arm: bool,
  91     pub(super) has_item_list_or_source_file_parent: bool,
  92     pub(super) for_is_prev2: bool,
  93     pub(super) fn_is_prev: bool,
  94     pub(super) incomplete_let: bool,
  95     pub(super) locals: Vec<(String, Local)>,
  96 }
  97
  98 impl<'a> CompletionContext<'a> {
  99     pub(super) fn new(
 100         db: &'a RootDatabase,
 101         position: FilePosition,
 102         config: &'a CompletionConfig,
 103     ) -> Option<CompletionContext<'a>> {
 104         let sema = Semantics::new(db);
 105
 106         let original_file = sema.parse(position.file_id);
 107
 108         // Insert a fake ident to get a valid parse tree. We will use this file
 109         // to determine context, though the original_file will be used for
 110         // actual completion.
 111         let file_with_fake_ident = {
 112             let parse = db.parse(position.file_id);
 113             let edit = Indel::insert(position.offset, "intellijRulezz".to_string());
 114             parse.reparse(&edit).tree()
 115         };
 116         let fake_ident_token =
 117             file_with_fake_ident.syntax().token_at_offset(position.offset).right_biased().unwrap();
 118
 119         let krate = sema.to_module_def(position.file_id).map(|m| m.krate());
 120         let original_token =
 121             original_file.syntax().token_at_offset(position.offset).left_biased()?;
 122         let token = sema.descend_into_macros(original_token.clone());
 123         let scope = sema.scope_at_offset(&token.parent(), position.offset);
 124         let mut locals = vec![];
 125         scope.process_all_names(&mut |name, scope| {
 126             if let ScopeDef::Local(local) = scope {
 127                 locals.push((name.to_string(), local));
 128             }
 129         });
 130         let mut ctx = CompletionContext {
 131             sema,
 132             scope,
 133             db,
 134             config,
 135             position,
 136             original_token,
 137             token,
 138             krate,
 139             expected_name: None,
 140             expected_type: None,
 141             name_ref_syntax: None,
 142             function_syntax: None,
 143             use_item_syntax: None,
 144             record_lit_syntax: None,
 145             record_pat_syntax: None,
 146             record_field_syntax: None,
 147             impl_def: None,
 148             active_parameter: ActiveParameter::at(db, position),
 149             is_param: false,
 150             is_pat_binding_or_const: false,
 151             is_irrefutable_pat_binding: false,
 152             is_trivial_path: false,
 153             path_qual: None,
 154             after_if: false,
 155             can_be_stmt: false,
 156             is_expr: false,
 157             is_new_item: false,
 158             dot_receiver: None,
 159             dot_receiver_is_ambiguous_float_literal: false,
 160             is_call: false,
 161             is_pattern_call: false,
 162             is_macro_call: false,
 163             is_path_type: false,
 164             has_type_args: false,
 165             attribute_under_caret: None,
 166             mod_declaration_under_caret: None,
 167             unsafe_is_prev: false,
 168             if_is_prev: false,
 169             block_expr_parent: false,
 170             bind_pat_parent: false,
 171             ref_pat_parent: false,
 172             in_loop_body: false,
 173             has_trait_parent: false,
 174             has_impl_parent: false,
 175             inside_impl_trait_block: false,
 176             has_field_list_parent: false,
 177             trait_as_prev_sibling: false,
 178             impl_as_prev_sibling: false,
 179             is_match_arm: false,
 180             has_item_list_or_source_file_parent: false,
 181             for_is_prev2: false,
 182             fn_is_prev: false,
 183             incomplete_let: false,
 184             locals,
 185         };
 186
 187         let mut original_file = original_file.syntax().clone();
 188         let mut hypothetical_file = file_with_fake_ident.syntax().clone();
 189         let mut offset = position.offset;
 190         let mut fake_ident_token = fake_ident_token;
 191
 192         // Are we inside a macro call?
 193         while let (Some(actual_macro_call), Some(macro_call_with_fake_ident)) = (
 194             find_node_at_offset::<ast::MacroCall>(&original_file, offset),
 195             find_node_at_offset::<ast::MacroCall>(&hypothetical_file, offset),
 196         ) {
 197             if actual_macro_call.path().as_ref().map(|s| s.syntax().text())
 198                 != macro_call_with_fake_ident.path().as_ref().map(|s| s.syntax().text())
 199             {
 200                 break;
 201             }
 202             let hypothetical_args = match macro_call_with_fake_ident.token_tree() {
 203                 Some(tt) => tt,
 204                 None => break,
 205             };
 206             if let (Some(actual_expansion), Some(hypothetical_expansion)) = (
 207                 ctx.sema.expand(&actual_macro_call),
 208                 ctx.sema.speculative_expand(
 209                     &actual_macro_call,
 210                     &hypothetical_args,
 211                     fake_ident_token,
 212                 ),
 213             ) {
 214                 let new_offset = hypothetical_expansion.1.text_range().start();
 215                 if new_offset > actual_expansion.text_range().end() {
 216                     break;
 217                 }
 218                 original_file = actual_expansion;
 219                 hypothetical_file = hypothetical_expansion.0;
 220                 fake_ident_token = hypothetical_expansion.1;
 221                 offset = new_offset;
 222             } else {
 223                 break;
 224             }
 225         }
 226         ctx.fill_keyword_patterns(&hypothetical_file, offset);
 227         ctx.fill(&original_file, hypothetical_file, offset);
 228         Some(ctx)
 229     }
 230
 231     /// Checks whether completions in that particular case don't make much sense.
 232     /// Examples:
 233     /// - `fn $0` -- we expect function name, it's unlikely that "hint" will be helpful.
 234     ///   Exception for this case is `impl Trait for Foo`, where we would like to hint trait method names.
 235     /// - `for _ i$0` -- obviously, it'll be "in" keyword.
 236     pub(crate) fn no_completion_required(&self) -> bool {
 237         (self.fn_is_prev && !self.inside_impl_trait_block) || self.for_is_prev2
 238     }
 239
 240     /// The range of the identifier that is being completed.
 241     pub(crate) fn source_range(&self) -> TextRange {
 242         // check kind of macro-expanded token, but use range of original token
 243         let kind = self.token.kind();
 244         if kind == IDENT || kind == UNDERSCORE || kind.is_keyword() {
 245             cov_mark::hit!(completes_if_prefix_is_keyword);
 246             self.original_token.text_range()
 247         } else {
 248             TextRange::empty(self.position.offset)
 249         }
 250     }
 251
 252     fn fill_keyword_patterns(&mut self, file_with_fake_ident: &SyntaxNode, offset: TextSize) {
 253         let fake_ident_token = file_with_fake_ident.token_at_offset(offset).right_biased().unwrap();
 254         let syntax_element = NodeOrToken::Token(fake_ident_token);
 255         self.block_expr_parent = has_block_expr_parent(syntax_element.clone());
 256         self.unsafe_is_prev = unsafe_is_prev(syntax_element.clone());
 257         self.if_is_prev = if_is_prev(syntax_element.clone());
 258         self.bind_pat_parent = has_bind_pat_parent(syntax_element.clone());
 259         self.ref_pat_parent = has_ref_parent(syntax_element.clone());
 260         self.in_loop_body = is_in_loop_body(syntax_element.clone());
 261         self.has_trait_parent = has_trait_parent(syntax_element.clone());
 262         self.has_impl_parent = has_impl_parent(syntax_element.clone());
 263         self.inside_impl_trait_block = inside_impl_trait_block(syntax_element.clone());
 264         self.has_field_list_parent = has_field_list_parent(syntax_element.clone());
 265         self.impl_as_prev_sibling = has_impl_as_prev_sibling(syntax_element.clone());
 266         self.trait_as_prev_sibling = has_trait_as_prev_sibling(syntax_element.clone());
 267         self.is_match_arm = is_match_arm(syntax_element.clone());
 268         self.has_item_list_or_source_file_parent =
 269             has_item_list_or_source_file_parent(syntax_element.clone());
 270         self.mod_declaration_under_caret =
 271             find_node_at_offset::<ast::Module>(&file_with_fake_ident, offset)
 272                 .filter(|module| module.item_list().is_none());
 273         self.for_is_prev2 = for_is_prev2(syntax_element.clone());
 274         self.fn_is_prev = fn_is_prev(syntax_element.clone());
 275         self.incomplete_let =
 276             syntax_element.ancestors().take(6).find_map(ast::LetStmt::cast).map_or(false, |it| {
 277                 it.syntax().text_range().end() == syntax_element.text_range().end()
 278             });
 279     }
 280
 281     fn fill_impl_def(&mut self) {
 282         self.impl_def = self
 283             .sema
 284             .ancestors_with_macros(self.token.parent())
 285             .take_while(|it| it.kind() != SOURCE_FILE && it.kind() != MODULE)
 286             .find_map(ast::Impl::cast);
 287     }
 288
 289     fn fill(
 290         &mut self,
 291         original_file: &SyntaxNode,
 292         file_with_fake_ident: SyntaxNode,
 293         offset: TextSize,
 294     ) {
 295         let expected = {
 296             let mut node = self.token.parent();
 297             loop {
 298                 let ret = match_ast! {
 299                     match node {
 300                         ast::LetStmt(it) => {
 301                             cov_mark::hit!(expected_type_let_with_leading_char);
 302                             cov_mark::hit!(expected_type_let_without_leading_char);
 303                             let ty = it.pat()
 304                                 .and_then(|pat| self.sema.type_of_pat(&pat));
 305                             let name = if let Some(ast::Pat::IdentPat(ident)) = it.pat() {
 306                                 Some(ident.syntax().text().to_string())
 307                             } else {
 308                                 None
 309                             };
 310
 311                             (ty, name)
 312                         },
 313                         ast::ArgList(it) => {
 314                             cov_mark::hit!(expected_type_fn_param_with_leading_char);
 315                             cov_mark::hit!(expected_type_fn_param_without_leading_char);
 316                             ActiveParameter::at_token(
 317                                 &self.sema,
 318                                 self.token.clone(),
 319                             ).map(|ap| (Some(ap.ty), Some(ap.name)))
 320                             .unwrap_or((None, None))
 321                         },
 322                         ast::RecordExprFieldList(it) => {
 323                             cov_mark::hit!(expected_type_struct_field_without_leading_char);
 324                             self.token.prev_sibling_or_token()
 325                                 .and_then(|se| se.into_node())
 326                                 .and_then(|node| ast::RecordExprField::cast(node))
 327                                 .and_then(|rf| self.sema.resolve_record_field(&rf))
 328                                 .map(|f|(
 329                                     Some(f.0.signature_ty(self.db)),
 330                                     Some(f.0.name(self.db).to_string()),
 331                                 ))
 332                                 .unwrap_or((None, None))
 333                         },
 334                         ast::RecordExprField(it) => {
 335                             cov_mark::hit!(expected_type_struct_field_with_leading_char);
 336                             self.sema
 337                                 .resolve_record_field(&it)
 338                                 .map(|f|(
 339                                     Some(f.0.signature_ty(self.db)),
 340                                     Some(f.0.name(self.db).to_string()),
 341                                 ))
 342                                 .unwrap_or((None, None))
 343                         },
 344                         ast::MatchExpr(it) => {
 345                             cov_mark::hit!(expected_type_match_arm_without_leading_char);
 346                             let ty = it.expr()
 347                                 .and_then(|e| self.sema.type_of_expr(&e));
 348
 349                             (ty, None)
 350                         },
 351                         ast::IdentPat(it) => {
 352                             cov_mark::hit!(expected_type_if_let_with_leading_char);
 353                             cov_mark::hit!(expected_type_if_let_without_leading_char);
 354                             cov_mark::hit!(expected_type_match_arm_with_leading_char);
 355                             let ty = self.sema.type_of_pat(&ast::Pat::from(it));
 356
 357                             (ty, None)
 358                         },
 359                         ast::Fn(it) => {
 360                             cov_mark::hit!(expected_type_fn_ret_with_leading_char);
 361                             cov_mark::hit!(expected_type_fn_ret_without_leading_char);
 362                             let ty = self.token.ancestors()
 363                                 .find_map(|ancestor| ast::Expr::cast(ancestor))
 364                                 .and_then(|expr| self.sema.type_of_expr(&expr));
 365
 366                             (ty, None)
 367                         },
 368                         _ => {
 369                             match node.parent() {
 370                                 Some(n) => {
 371                                     node = n;
 372                                     continue;
 373                                 },
 374                                 None => (None, None),
 375                             }
 376                         },
 377                     }
 378                 };
 379
 380                 break ret;
 381             }
 382         };
 383         self.expected_type = expected.0;
 384         self.expected_name = expected.1;
 385         self.attribute_under_caret = find_node_at_offset(&file_with_fake_ident, offset);
 386
 387         // First, let's try to complete a reference to some declaration.
 388         if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(&file_with_fake_ident, offset) {
 389             // Special case, `trait T { fn foo(i_am_a_name_ref) {} }`.
 390             // See RFC#1685.
 391             if is_node::<ast::Param>(name_ref.syntax()) {
 392                 self.is_param = true;
 393                 return;
 394             }
 395             // FIXME: remove this (V) duplication and make the check more precise
 396             if name_ref.syntax().ancestors().find_map(ast::RecordPatFieldList::cast).is_some() {
 397                 self.record_pat_syntax =
 398                     self.sema.find_node_at_offset_with_macros(&original_file, offset);
 399             }
 400             self.classify_name_ref(original_file, name_ref, offset);
 401         }
 402
 403         // Otherwise, see if this is a declaration. We can use heuristics to
 404         // suggest declaration names, see `CompletionKind::Magic`.
 405         if let Some(name) = find_node_at_offset::<ast::Name>(&file_with_fake_ident, offset) {
 406             if let Some(bind_pat) = name.syntax().ancestors().find_map(ast::IdentPat::cast) {
 407                 self.is_pat_binding_or_const = true;
 408                 if bind_pat.at_token().is_some()
 409                     || bind_pat.ref_token().is_some()
 410                     || bind_pat.mut_token().is_some()
 411                 {
 412                     self.is_pat_binding_or_const = false;
 413                 }
 414                 if bind_pat.syntax().parent().and_then(ast::RecordPatFieldList::cast).is_some() {
 415                     self.is_pat_binding_or_const = false;
 416                 }
 417                 if let Some(Some(pat)) = bind_pat.syntax().ancestors().find_map(|node| {
 418                     match_ast! {
 419                         match node {
 420                             ast::LetStmt(it) => Some(it.pat()),
 421                             ast::Param(it) => Some(it.pat()),
 422                             _ => None,
 423                         }
 424                     }
 425                 }) {
 426                     if pat.syntax().text_range().contains_range(bind_pat.syntax().text_range()) {
 427                         self.is_pat_binding_or_const = false;
 428                         self.is_irrefutable_pat_binding = true;
 429                     }
 430                 }
 431
 432                 self.fill_impl_def();
 433             }
 434             if is_node::<ast::Param>(name.syntax()) {
 435                 self.is_param = true;
 436                 return;
 437             }
 438             // FIXME: remove this (^) duplication and make the check more precise
 439             if name.syntax().ancestors().find_map(ast::RecordPatFieldList::cast).is_some() {
 440                 self.record_pat_syntax =
 441                     self.sema.find_node_at_offset_with_macros(&original_file, offset);
 442             }
 443         }
 444     }
 445
 446     fn classify_name_ref(
 447         &mut self,
 448         original_file: &SyntaxNode,
 449         name_ref: ast::NameRef,
 450         offset: TextSize,
 451     ) {
 452         self.name_ref_syntax =
 453             find_node_at_offset(&original_file, name_ref.syntax().text_range().start());
 454         let name_range = name_ref.syntax().text_range();
 455         if ast::RecordExprField::for_field_name(&name_ref).is_some() {
 456             self.record_lit_syntax =
 457                 self.sema.find_node_at_offset_with_macros(&original_file, offset);
 458         }
 459
 460         self.fill_impl_def();
 461
 462         let top_node = name_ref
 463             .syntax()
 464             .ancestors()
 465             .take_while(|it| it.text_range() == name_range)
 466             .last()
 467             .unwrap();
 468
 469         match top_node.parent().map(|it| it.kind()) {
 470             Some(SOURCE_FILE) | Some(ITEM_LIST) => {
 471                 self.is_new_item = true;
 472                 return;
 473             }
 474             _ => (),
 475         }
 476
 477         self.use_item_syntax =
 478             self.sema.ancestors_with_macros(self.token.parent()).find_map(ast::Use::cast);
 479
 480         self.function_syntax = self
 481             .sema
 482             .ancestors_with_macros(self.token.parent())
 483             .take_while(|it| it.kind() != SOURCE_FILE && it.kind() != MODULE)
 484             .find_map(ast::Fn::cast);
 485
 486         self.record_field_syntax = self
 487             .sema
 488             .ancestors_with_macros(self.token.parent())
 489             .take_while(|it| {
 490                 it.kind() != SOURCE_FILE && it.kind() != MODULE && it.kind() != CALL_EXPR
 491             })
 492             .find_map(ast::RecordExprField::cast);
 493
 494         let parent = match name_ref.syntax().parent() {
 495             Some(it) => it,
 496             None => return,
 497         };
 498
 499         if let Some(segment) = ast::PathSegment::cast(parent.clone()) {
 500             let path = segment.parent_path();
 501             self.is_call = path
 502                 .syntax()
 503                 .parent()
 504                 .and_then(ast::PathExpr::cast)
 505                 .and_then(|it| it.syntax().parent().and_then(ast::CallExpr::cast))
 506                 .is_some();
 507             self.is_macro_call = path.syntax().parent().and_then(ast::MacroCall::cast).is_some();
 508             self.is_pattern_call =
 509                 path.syntax().parent().and_then(ast::TupleStructPat::cast).is_some();
 510
 511             self.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some();
 512             self.has_type_args = segment.generic_arg_list().is_some();
 513
 514             if let Some(path) = path_or_use_tree_qualifier(&path) {
 515                 self.path_qual = path
 516                     .segment()
 517                     .and_then(|it| {
 518                         find_node_with_range::<ast::PathSegment>(
 519                             original_file,
 520                             it.syntax().text_range(),
 521                         )
 522                     })
 523                     .map(|it| it.parent_path());
 524                 return;
 525             }
 526
 527             if let Some(segment) = path.segment() {
 528                 if segment.coloncolon_token().is_some() {
 529                     return;
 530                 }
 531             }
 532
 533             self.is_trivial_path = true;
 534
 535             // Find either enclosing expr statement (thing with `;`) or a
 536             // block. If block, check that we are the last expr.
 537             self.can_be_stmt = name_ref
 538                 .syntax()
 539                 .ancestors()
 540                 .find_map(|node| {
 541                     if let Some(stmt) = ast::ExprStmt::cast(node.clone()) {
 542                         return Some(stmt.syntax().text_range() == name_ref.syntax().text_range());
 543                     }
 544                     if let Some(block) = ast::BlockExpr::cast(node) {
 545                         return Some(
 546                             block.tail_expr().map(|e| e.syntax().text_range())
 547                                 == Some(name_ref.syntax().text_range()),
 548                         );
 549                     }
 550                     None
 551                 })
 552                 .unwrap_or(false);
 553             self.is_expr = path.syntax().parent().and_then(ast::PathExpr::cast).is_some();
 554
 555             if let Some(off) = name_ref.syntax().text_range().start().checked_sub(2.into()) {
 556                 if let Some(if_expr) =
 557                     self.sema.find_node_at_offset_with_macros::<ast::IfExpr>(original_file, off)
 558                 {
 559                     if if_expr.syntax().text_range().end() < name_ref.syntax().text_range().start()
 560                     {
 561                         self.after_if = true;
 562                     }
 563                 }
 564             }
 565         }
 566         if let Some(field_expr) = ast::FieldExpr::cast(parent.clone()) {
 567             // The receiver comes before the point of insertion of the fake
 568             // ident, so it should have the same range in the non-modified file
 569             self.dot_receiver = field_expr
 570                 .expr()
 571                 .map(|e| e.syntax().text_range())
 572                 .and_then(|r| find_node_with_range(original_file, r));
 573             self.dot_receiver_is_ambiguous_float_literal =
 574                 if let Some(ast::Expr::Literal(l)) = &self.dot_receiver {
 575                     match l.kind() {
 576                         ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
 577                         _ => false,
 578                     }
 579                 } else {
 580                     false
 581                 };
 582         }
 583         if let Some(method_call_expr) = ast::MethodCallExpr::cast(parent) {
 584             // As above
 585             self.dot_receiver = method_call_expr
 586                 .receiver()
 587                 .map(|e| e.syntax().text_range())
 588                 .and_then(|r| find_node_with_range(original_file, r));
 589             self.is_call = true;
 590         }
 591     }
 592 }
 593
 594 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
 595     syntax.covering_element(range).ancestors().find_map(N::cast)
 596 }
 597
 598 fn is_node<N: AstNode>(node: &SyntaxNode) -> bool {
 599     match node.ancestors().find_map(N::cast) {
 600         None => false,
 601         Some(n) => n.syntax().text_range() == node.text_range(),
 602     }
 603 }
 604
 605 fn path_or_use_tree_qualifier(path: &ast::Path) -> Option<ast::Path> {
 606     if let Some(qual) = path.qualifier() {
 607         return Some(qual);
 608     }
 609     let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
 610     let use_tree = use_tree_list.syntax().parent().and_then(ast::UseTree::cast)?;
 611     use_tree.path()
 612 }
 613
 614 #[cfg(test)]
 615 mod tests {
 616     use expect_test::{expect, Expect};
 617     use hir::HirDisplay;
 618
 619     use crate::test_utils::{position, TEST_CONFIG};
 620
 621     use super::CompletionContext;
 622
 623     fn check_expected_type_and_name(ra_fixture: &str, expect: Expect) {
 624         let (db, pos) = position(ra_fixture);
 625         let completion_context = CompletionContext::new(&db, pos, &TEST_CONFIG).unwrap();
 626
 627         let ty = completion_context
 628             .expected_type
 629             .map(|t| t.display_test(&db).to_string())
 630             .unwrap_or("?".to_owned());
 631
 632         let name = completion_context.expected_name.unwrap_or("?".to_owned());
 633
 634         expect.assert_eq(&format!("ty: {}, name: {}", ty, name));
 635     }
 636
 637     #[test]
 638     fn expected_type_let_without_leading_char() {
 639         cov_mark::check!(expected_type_let_without_leading_char);
 640         check_expected_type_and_name(
 641             r#"
 642 fn foo() {
 643     let x: u32 = $0;
 644 }
 645 "#,
 646             expect![[r#"ty: u32, name: x"#]],
 647         );
 648     }
 649
 650     #[test]
 651     fn expected_type_let_with_leading_char() {
 652         cov_mark::check!(expected_type_let_with_leading_char);
 653         check_expected_type_and_name(
 654             r#"
 655 fn foo() {
 656     let x: u32 = c$0;
 657 }
 658 "#,
 659             expect![[r#"ty: u32, name: x"#]],
 660         );
 661     }
 662
 663     #[test]
 664     fn expected_type_fn_param_without_leading_char() {
 665         cov_mark::check!(expected_type_fn_param_without_leading_char);
 666         check_expected_type_and_name(
 667             r#"
 668 fn foo() {
 669     bar($0);
 670 }
 671
 672 fn bar(x: u32) {}
 673 "#,
 674             expect![[r#"ty: u32, name: x"#]],
 675         );
 676     }
 677
 678     #[test]
 679     fn expected_type_fn_param_with_leading_char() {
 680         cov_mark::check!(expected_type_fn_param_with_leading_char);
 681         check_expected_type_and_name(
 682             r#"
 683 fn foo() {
 684     bar(c$0);
 685 }
 686
 687 fn bar(x: u32) {}
 688 "#,
 689             expect![[r#"ty: u32, name: x"#]],
 690         );
 691     }
 692
 693     #[test]
 694     fn expected_type_struct_field_without_leading_char() {
 695         cov_mark::check!(expected_type_struct_field_without_leading_char);
 696         check_expected_type_and_name(
 697             r#"
 698 struct Foo { a: u32 }
 699 fn foo() {
 700     Foo { a: $0 };
 701 }
 702 "#,
 703             expect![[r#"ty: u32, name: a"#]],
 704         )
 705     }
 706
 707     #[test]
 708     fn expected_type_struct_field_with_leading_char() {
 709         cov_mark::check!(expected_type_struct_field_with_leading_char);
 710         check_expected_type_and_name(
 711             r#"
 712 struct Foo { a: u32 }
 713 fn foo() {
 714     Foo { a: c$0 };
 715 }
 716 "#,
 717             expect![[r#"ty: u32, name: a"#]],
 718         );
 719     }
 720
 721     #[test]
 722     fn expected_type_match_arm_without_leading_char() {
 723         cov_mark::check!(expected_type_match_arm_without_leading_char);
 724         check_expected_type_and_name(
 725             r#"
 726 enum E { X }
 727 fn foo() {
 728    match E::X { $0 }
 729 }
 730 "#,
 731             expect![[r#"ty: E, name: ?"#]],
 732         );
 733     }
 734
 735     #[test]
 736     fn expected_type_match_arm_with_leading_char() {
 737         cov_mark::check!(expected_type_match_arm_with_leading_char);
 738         check_expected_type_and_name(
 739             r#"
 740 enum E { X }
 741 fn foo() {
 742    match E::X { c$0 }
 743 }
 744 "#,
 745             expect![[r#"ty: E, name: ?"#]],
 746         );
 747     }
 748
 749     #[test]
 750     fn expected_type_if_let_without_leading_char() {
 751         cov_mark::check!(expected_type_if_let_without_leading_char);
 752         check_expected_type_and_name(
 753             r#"
 754 enum Foo { Bar, Baz, Quux }
 755
 756 fn foo() {
 757     let f = Foo::Quux;
 758     if let $0 = f { }
 759 }
 760 "#,
 761             expect![[r#"ty: (), name: ?"#]],
 762         ) // FIXME should be `ty: u32, name: ?`
 763     }
 764
 765     #[test]
 766     fn expected_type_if_let_with_leading_char() {
 767         cov_mark::check!(expected_type_if_let_with_leading_char);
 768         check_expected_type_and_name(
 769             r#"
 770 enum Foo { Bar, Baz, Quux }
 771
 772 fn foo() {
 773     let f = Foo::Quux;
 774     if let c$0 = f { }
 775 }
 776 "#,
 777             expect![[r#"ty: Foo, name: ?"#]],
 778         )
 779     }
 780
 781     #[test]
 782     fn expected_type_fn_ret_without_leading_char() {
 783         cov_mark::check!(expected_type_fn_ret_without_leading_char);
 784         check_expected_type_and_name(
 785             r#"
 786 fn foo() -> u32 {
 787     $0
 788 }
 789 "#,
 790             expect![[r#"ty: (), name: ?"#]],
 791         ) // FIXME this should be `ty: u32, name: ?`
 792     }
 793
 794     #[test]
 795     fn expected_type_fn_ret_with_leading_char() {
 796         cov_mark::check!(expected_type_fn_ret_with_leading_char);
 797         check_expected_type_and_name(
 798             r#"
 799 fn foo() -> u32 {
 800     c$0
 801 }
 802 "#,
 803             expect![[r#"ty: u32, name: ?"#]],
 804         )
 805     }
 806 }