LS: Fix hover definition lookup logic

Since ba74ab1 the hover logic wrongly
tried to find definition lookup item by inspecting originating location
within `get_definition_location`. The bug was introduced by making an
attempt to share the definition lookup logic with _goto definition_,
where actually both features need different results.

commit-id:f3e136e6

crates/cairo-lang-language-server/src/ide/hover.rs

@@ -1,10 +1,11 @@
 use cairo_lang_compiler::db::RootDatabase;
 use cairo_lang_defs::db::DefsGroup;
 use cairo_lang_defs::ids::LookupItemId;
+use cairo_lang_syntax::node::TypedSyntaxNode;
 use cairo_lang_utils::Upcast;
 use tower_lsp::lsp_types::{Hover, HoverContents, HoverParams, MarkedString};
 
-use crate::get_definition_location;
+use crate::find_definition;
 use crate::lang::lsp::{LsProtoGroup, ToCairo};
 use crate::lang::semantic::LsSemanticGroup;
 use crate::lang::syntax::LsSyntaxGroup;
@@ -18,14 +19,15 @@ use crate::lang::syntax::LsSyntaxGroup;
 pub fn hover(params: HoverParams, db: &RootDatabase) -> Option<Hover> {
     let file_id = db.file_for_url(&params.text_document_position_params.text_document.uri);
     let position = params.text_document_position_params.position.to_cairo();
-    // Get the item id of the definition.
-    let (found_file, span) = get_definition_location(db, file_id, position)?;
-    // Get the documentation and declaration of the item.
-    let node = db.find_syntax_node_at_position(
-        found_file,
-        span.start.position_in_file(db.upcast(), found_file)?,
-    )?;
-    let lookup_item = db.find_lookup_item(&node)?;
+    // Get the syntax node of the definition.
+    let definition_node = {
+        let identifier = db.find_identifier_at_position(file_id, position)?;
+        let lookup_items = db.collect_lookup_items_stack(&identifier.as_syntax_node())?;
+        let stable_ptr = find_definition(db, &identifier, &lookup_items)?;
+        stable_ptr.lookup(db.upcast())
+    };
+    // Get the lookup item representing the defining item.
+    let lookup_item = db.find_lookup_item(&definition_node)?;
     // Build texts.
     let mut hints = Vec::new();
     if let Some(hint) = get_expr_hint(db.upcast(), lookup_item) {

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

@@ -121,7 +121,7 @@ fn starknet() {
 
                 #[constructor]
                 fn constructor(ref se<caret>lf: Cont<caret>ractState, value_: u128) {
-                    self.va<caret>lue.write(value_);
+                    self.va<caret>lue.write(v<caret>alue_);
                 }
 
                 #[abi(embed_v0)]
@@ -130,7 +130,7 @@ fn starknet() {
                         self.value.r<caret>ead()
                     }
                     fn increase(ref self: ContractState, a: u128)  {
-                        self.value.wr<caret>ite( self.value.read() + a );
+                        self.value.wr<caret>ite( self.value.read() + <caret>a );
                     }
                 }
             }

crates/cairo-lang-language-server/tests/test_data/hover/starknet.txt

@@ -5,8 +5,9 @@ use Balance::contract_state_for_testing;
                   ↑
 
 //! > popover
-No hover information.
-
+```cairo
+pub fn contract_state_for_testing() -> ContractState
+```
 =========
 
 //! > hover at Position { line: 23, character: 25 }
@@ -27,8 +28,14 @@ No hover information.
                                  ↑
 
 //! > popover
-No hover information.
+```cairo
+
+
+    pub struct ContractState {
+        pub value: __member_module_value::ContractMemberState,
+    }
 
+```
 =========
 
 //! > hover at Position { line: 24, character: 15 }
@@ -42,6 +49,18 @@ No hover information.
 
 =========
 
+//! > hover at Position { line: 24, character: 26 }
+
+//! > source context
+        self.value.write(value_);
+                          ↑
+
+//! > popover
+```cairo
+fn constructor(ref self: ContractState, value_: u128)
+```
+=========
+
 //! > hover at Position { line: 28, character: 30 }
 
 //! > source context
@@ -64,8 +83,14 @@ No hover information.
                                        ↑
 
 //! > popover
-No hover information.
+```cairo
 
+
+    pub struct ContractState {
+        pub value: __member_module_value::ContractMemberState,
+    }
+
+```
 =========
 
 //! > hover at Position { line: 30, character: 24 }
@@ -92,3 +117,15 @@ fn write(ref self: TMemberState, value: Self::Value);
 ```
 =========
 
+//! > hover at Position { line: 33, character: 50 }
+
+//! > source context
+            self.value.write( self.value.read() + a );
+                                                  ↑
+
+//! > popover
+```cairo
+fn increase(ref self: ContractState, a: u128)
+```
+=========
+