Allow alternate binding assertion anchor for targets at the same colu…

…mn as the comment

crates/solidity/outputs/cargo/tests/src/bindings_assertions/assertions.rs

@@ -127,7 +127,7 @@ impl<'a> fmt::Display for DisplayCursor<'a> {
 ///   uint x;
 ///   //   ^def:1
 ///
-/// asserts that at the CST node above the caret symbol (same column, not
+/// asserts that at the CST node above the caret symbol `^` (same column, not
 /// necessarily in the previous line), the identifier `x` should create a
 /// binding definition, and assigns it an ID of '1'.
 ///
@@ -142,6 +142,13 @@ impl<'a> fmt::Display for DisplayCursor<'a> {
 /// '1'; and that the CST identifier node `y` should be a binding reference that
 /// is unresolved for version at or above 0.5.0.
 ///
+/// For assertion targets that are located at the column where the comment
+/// begins the alternative anchor `<` can be used. For example:
+///
+///   x = y + 1;
+///   //  ^ref:2
+///   //<ref:1
+///
 pub fn collect_assertions(cursor: Cursor, version: &Version) -> Result<Assertions, AssertionError> {
     let mut assertions = Assertions::new();
 
@@ -173,7 +180,7 @@ enum Assertion {
 }
 
 static ASSERTION_REGEX: Lazy<Regex> = Lazy::new(|| {
-    Regex::new(r"[\^](?<type>ref|def):(?<id>[0-9a-zA-Z_-]+|!)([\t ]*\((?<version>[^)]+)\))?")
+    Regex::new(r"(?<anchor>[\^]|[<])(?<type>ref|def):(?<id>[0-9a-zA-Z_-]+|!)([\t ]*\((?<version>[^)]+)\))?")
         .unwrap()
 });
 
@@ -191,7 +198,13 @@ fn find_assertion_in_comment(
 
     let assertion_id = captures.name("id").unwrap().as_str();
     let assertion_type = captures.name("type").unwrap().as_str();
-    let assertion_col = comment_col + captures.get(0).unwrap().start();
+    let assertion_anchor = captures.name("anchor").unwrap();
+    let assertion_col = comment_col
+        + if assertion_anchor.as_str() == "^" {
+            assertion_anchor.start()
+        } else {
+            0
+        };
     let version_req = match captures.name("version") {
         Some(version) => {
             let Ok(version_req) = VersionReq::parse(version.as_str()) else {

crates/solidity/testing/snapshots/bindings_assertions/contracts/visibility.sol

@@ -3,7 +3,7 @@ contract First {
     enum Choice { One, Two }
     //   ^def:2
     Choice choice;
-//  ^ref:2
+    //<ref:2
     //     ^def:3
     function get_choice() public returns (Choice) {
         //   ^def:4
@@ -14,7 +14,7 @@ contract First {
 
 contract Second {
     First.Choice choice;
-//  ^ref:1
+    //<ref:1
     //    ^ref:2
     //           ^def:5
 

crates/solidity/testing/snapshots/bindings_assertions/enums/in_state_vars.sol

@@ -4,7 +4,7 @@ contract Foo {
     //            ^def:2
     //   ^def:1
     Answer choice = Answer.Yes;
-//  ^ref:1
+    //<ref:1
     //                     ^ref:2
     //              ^ref:1
 }

crates/solidity/testing/snapshots/bindings_assertions/expressions/function_call.sol

@@ -11,7 +11,7 @@ contract Test {
         //      ^ref:5
         //  ^def:3
         pointless(z, x);
-    //  ^ref:4
+        //<ref:4
         //           ^ref:1
         //        ^ref:3
     }

crates/solidity/testing/snapshots/bindings_assertions/interfaces/visibility.sol

@@ -12,14 +12,14 @@ interface Example {
 
 contract Test {
     Example.Choice choice = Example.Choice.One;
-//  ^ref:1
+    //<ref:1
     //      ^ref:2
     //             ^def:7
     //                      ^ref:1
     //                              ^ref:2
     //                                     ^ref:5
     Example.Book book;
-//  ^ref:1
+    //<ref:1
     //      ^ref:3
 
     function my_test() returns (int) {

crates/solidity/testing/snapshots/bindings_assertions/scoping/c99_scopes.sol

@@ -19,7 +19,7 @@ contract Foo {
     function another_func() returns (uint y) {
         //                                ^def:5
         y = x + w;
-     // ^ref:5
+        //<ref:5
         //      ^ref:! (>=0.5.0)
         //      ^ref:6 (<0.5.0)
         //  ^ref:1

crates/solidity/testing/snapshots/bindings_assertions/scoping/hoisting_scopes.sol

@@ -3,7 +3,7 @@ contract Foo {
   function bar() returns (int x) {
     //                        ^def:1
     x = y + z;
-//  ^ref:1
+    //<ref:1
     //      ^ref:3 (<0.5.0)
     //      ^ref:! (>=0.5.0)
     //  ^ref:2 (<0.5.0)

crates/solidity/testing/snapshots/bindings_assertions/variables/destructuring.sol

@@ -16,6 +16,8 @@ library Test {
         //         ^ref:7
         //     ^ref:5
         (, Choice c) = (Choice.Yes, Choice.No);
+        //                          ^ref:1
+        //              ^ref:1
         //        ^def:8
         // ^ref:1
 

crates/solidity/testing/snapshots/bindings_assertions/variables/params.sol

@@ -16,6 +16,6 @@ contract Foo {
         //            ^def:3
         y = x + 5;
         //  ^ref:3
-    //  ^ref:2
+        //<ref:2
     }
 }