LS: Add completions of struct members

commit-id:9fb1df2c

crates/cairo-lang-language-server/src/ide/completion/completions.rs

@@ -11,7 +11,9 @@ use cairo_lang_semantic::db::SemanticGroup;
 use cairo_lang_semantic::diagnostic::{NotFoundItemType, SemanticDiagnostics};
 use cairo_lang_semantic::expr::inference::InferenceId;
 use cairo_lang_semantic::items::function_with_body::SemanticExprLookup;
+use cairo_lang_semantic::items::structure::concrete_struct_members;
 use cairo_lang_semantic::items::us::SemanticUseEx;
+use cairo_lang_semantic::items::visibility::peek_visible_in;
 use cairo_lang_semantic::lookup_item::{HasResolverData, LookupItemEx};
 use cairo_lang_semantic::resolve::{ResolvedConcreteItem, ResolvedGenericItem, Resolver};
 use cairo_lang_semantic::types::peel_snapshots;
@@ -318,3 +320,67 @@ fn module_has_trait(
     }
     Some(false)
 }
+
+/// Discovers members of a struct the [`ExprStructCtorCall`] refers to and returns completions with
+/// those which have not yet been specified in the constructor call.
+pub fn struct_constructor_completions(
+    db: &AnalysisDatabase,
+    lookup_items: Vec<LookupItemId>,
+    constructor: ast::ExprStructCtorCall,
+) -> Option<Vec<CompletionItem>> {
+    let module_id = db.find_module_containing_node(&constructor.as_syntax_node())?;
+    let lookup_item_id = lookup_items.into_iter().next()?;
+    let function_id = lookup_item_id.function_with_body()?;
+
+    let already_present_members = constructor
+        .arguments(db)
+        .arguments(db)
+        .elements(db)
+        .into_iter()
+        .filter_map(|member| match member {
+            ast::StructArg::StructArgSingle(struct_arg_single) => {
+                Some(struct_arg_single.identifier(db).token(db).as_syntax_node().get_text(db))
+            }
+            // although tail covers all remaining unspecified members, we still want to show them in
+            // completion.
+            ast::StructArg::StructArgTail(_) => None,
+        })
+        .collect::<Vec<_>>();
+
+    let constructor_expr_id =
+        db.lookup_expr_by_ptr(function_id, constructor.stable_ptr().into()).ok()?;
+
+    let semantic_expr = db.expr_semantic(function_id, constructor_expr_id);
+
+    let cairo_lang_semantic::Expr::StructCtor(constructor_semantic_expr) = semantic_expr else {
+        return None;
+    };
+
+    let struct_parent_module_id =
+        constructor_semantic_expr.concrete_struct_id.struct_id(db).parent_module(db);
+
+    let struct_members =
+        concrete_struct_members(db, constructor_semantic_expr.concrete_struct_id).ok()?;
+
+    let completions = struct_members
+        .iter()
+        .filter_map(|(name, data)| {
+            let name = name.to_string();
+
+            let visible = peek_visible_in(db, data.visibility, struct_parent_module_id, module_id);
+
+            if !visible || already_present_members.contains(&name) {
+                None
+            } else {
+                Some(CompletionItem {
+                    label: name,
+                    detail: Some(data.ty.format(db)),
+                    kind: Some(CompletionItemKind::VALUE),
+                    ..Default::default()
+                })
+            }
+        })
+        .collect::<Vec<_>>();
+
+    if completions.is_empty() { None } else { Some(completions) }
+}

crates/cairo-lang-language-server/src/ide/completion/mod.rs

@@ -1,12 +1,14 @@
+use cairo_lang_filesystem::ids::FileId;
 use cairo_lang_semantic::items::us::get_use_path_segments;
 use cairo_lang_semantic::resolve::AsSegments;
 use cairo_lang_syntax::node::ast::PathSegment;
 use cairo_lang_syntax::node::db::SyntaxGroup;
 use cairo_lang_syntax::node::kind::SyntaxKind;
 use cairo_lang_syntax::node::{SyntaxNode, TypedSyntaxNode, ast};
 use cairo_lang_utils::Upcast;
-use lsp_types::{CompletionParams, CompletionResponse, CompletionTriggerKind};
-use tracing::debug;
+use completions::struct_constructor_completions;
+use lsp_types::{CompletionParams, CompletionResponse, CompletionTriggerKind, Position};
+use tracing::{debug, info};
 
 use self::completions::{colon_colon_completions, dot_completions, generic_completions};
 use crate::lang::db::{AnalysisDatabase, LsSemanticGroup, LsSyntaxGroup};
@@ -36,14 +38,18 @@ pub fn complete(params: CompletionParams, db: &AnalysisDatabase) -> Option<Compl
     let trigger_kind =
         params.context.map(|it| it.trigger_kind).unwrap_or(CompletionTriggerKind::INVOKED);
 
-    match completion_kind(db, node) {
+    match completion_kind(db, node, position, file_id) {
         CompletionKind::Dot(expr) => {
             dot_completions(db, file_id, lookup_items, expr).map(CompletionResponse::Array)
         }
         CompletionKind::ColonColon(segments) if !segments.is_empty() => {
             colon_colon_completions(db, module_file_id, lookup_items, segments)
                 .map(CompletionResponse::Array)
         }
+        CompletionKind::StructConstructor(constructor) => {
+            struct_constructor_completions(db, lookup_items, constructor)
+                .map(CompletionResponse::Array)
+        }
         _ if trigger_kind == CompletionTriggerKind::INVOKED => {
             Some(CompletionResponse::Array(generic_completions(db, module_file_id, lookup_items)))
         }
@@ -54,10 +60,16 @@ pub fn complete(params: CompletionParams, db: &AnalysisDatabase) -> Option<Compl
 enum CompletionKind {
     Dot(ast::ExprBinary),
     ColonColon(Vec<PathSegment>),
+    StructConstructor(ast::ExprStructCtorCall),
 }
 
-fn completion_kind(db: &AnalysisDatabase, node: SyntaxNode) -> CompletionKind {
-    debug!("node.kind: {:#?}", node.kind(db));
+fn completion_kind(
+    db: &AnalysisDatabase,
+    node: SyntaxNode,
+    position: Position,
+    file_id: FileId,
+) -> CompletionKind {
+    info!("node.kind: {:#?}", node.kind(db));
     match node.kind(db) {
         SyntaxKind::TerminalDot => {
             let parent = node.parent().unwrap();
@@ -136,6 +148,49 @@ fn completion_kind(db: &AnalysisDatabase, node: SyntaxNode) -> CompletionKind {
                 return CompletionKind::ColonColon(segments);
             }
         }
+        SyntaxKind::TerminalLBrace | SyntaxKind::TerminalRBrace | SyntaxKind::TerminalComma => {
+            if let Some(constructor_node) =
+                db.first_ancestor_of_kind(node, SyntaxKind::ExprStructCtorCall)
+            {
+                return CompletionKind::StructConstructor(
+                    ast::ExprStructCtorCall::from_syntax_node(db, constructor_node),
+                );
+            }
+        }
+        // Show completions only if struct tail is separated from the cursor by a newline.
+        // Exclude cases like: `<cursor>..id`, `.<cursor>.id`, `..<cursor>id`
+        SyntaxKind::TerminalDotDot => {
+            let dot_dot_node_trivia = ast::TerminalDotDot::from_syntax_node(db, node.clone())
+                .leading_trivia(db)
+                .elements(db);
+
+            let mut generate_completion = false;
+            let mut node_found_in_trivia = false;
+
+            if let Some(node_at_position) =
+                db.find_syntax_node_at_position(file_id, position.to_cairo())
+            {
+                for trivium in dot_dot_node_trivia {
+                    if trivium.as_syntax_node() == node_at_position {
+                        node_found_in_trivia = true;
+                    }
+
+                    if node_found_in_trivia && matches!(trivium, ast::Trivium::Newline(_)) {
+                        generate_completion = true;
+                    }
+                }
+            }
+
+            if generate_completion {
+                if let Some(constructor_node) =
+                    db.first_ancestor_of_kind(node, SyntaxKind::ExprStructCtorCall)
+                {
+                    return CompletionKind::StructConstructor(
+                        ast::ExprStructCtorCall::from_syntax_node(db, constructor_node),
+                    );
+                }
+            }
+        }
         _ => (),
     }
     debug!("Generic");

crates/cairo-lang-language-server/tests/e2e/completions.rs

@@ -10,6 +10,7 @@ cairo_lang_test_utils::test_file_test!(
     "tests/test_data/completions",
     {
         methods_text_edits: "methods_text_edits.txt",
+        structs: "structs.txt",
     },
     test_completions_text_edits
 

crates/cairo-lang-language-server/tests/test_data/completions/structs.txt

@@ -0,0 +1,126 @@
+//! > Test completing struct members upon construction.
+
+//! > test_runner_name
+test_completions_text_edits(detail: true)
+
+//! > cairo_project.toml
+[crate_roots]
+hello = "src"
+
+[config.global]
+edition = "2024_07"
+
+//! > cairo_code
+mod some_module {
+    pub struct Struct {
+        x: u32,
+        pub y: felt252,
+        pub z: i16
+    }
+
+    fn build_struct() {
+        let s = Struct {
+            x: 0x0,
+            y: 0x0,
+            z: 0x0
+        };
+
+        let a = Struct {
+            <caret>
+        };
+
+        let b = Struct {
+            x: 0x0,
+            <caret>
+        };
+
+        let c = Struct {
+            x: 0x0,
+            <caret>
+            ..s
+        };
+    }
+}
+
+mod happy_cases {
+    use super::some_module::Struct;
+
+    fn foo() {
+        let a = Struct {
+            <caret>
+        };
+
+        let b = Struct {
+            y: 0x0,
+            <caret>
+        };
+
+        let c = Struct {
+            y: 0x0,
+            x: 0x0,
+            <caret>
+        }
+    }
+}
+
+mod unhappy_cases {
+    fn foo() {
+        let a = NonexsitentStruct {
+            <caret>
+        };
+    }
+}
+
+//! > Completions #0
+            <caret>
+--------------------------
+Completion: x
+Detail: core::integer::u32
+--------------------------
+Completion: y
+Detail: core::felt252
+--------------------------
+Completion: z
+Detail: core::integer::i16
+
+//! > Completions #1
+            <caret>
+--------------------------
+Completion: y
+Detail: core::felt252
+--------------------------
+Completion: z
+Detail: core::integer::i16
+
+//! > Completions #2
+            <caret>
+--------------------------
+Completion: y
+Detail: core::felt252
+--------------------------
+Completion: z
+Detail: core::integer::i16
+
+//! > Completions #3
+            <caret>
+--------------------------
+Completion: y
+Detail: core::felt252
+--------------------------
+Completion: z
+Detail: core::integer::i16
+
+//! > Completions #4
+            <caret>
+--------------------------
+Completion: z
+Detail: core::integer::i16
+
+//! > Completions #5
+            <caret>
+--------------------------
+Completion: z
+Detail: core::integer::i16
+
+//! > Completions #6
+            <caret>