add one more test

Author: VolodymyrBg

crates/linking/src/lib.rs

@@ -105,29 +105,18 @@ impl<'a> Linker<'a> {
     ) -> Result<(), LinkerError> {
         let contract = self.contracts.get(target).ok_or(LinkerError::MissingTargetArtifact)?;
 
-        // Collect union of library names per file (offsets are irrelevant for dependency graph).
-        let mut references: BTreeMap<String, BTreeSet<String>> = BTreeMap::new();
+        let mut references = BTreeMap::new();
         if let Some(bytecode) = &contract.bytecode {
-            for (file, libs) in &bytecode.link_references {
-                let entry = references.entry(file.clone()).or_default();
-                for name in libs.keys() {
-                    entry.insert(name.clone());
-                }
-            }
+            references.extend(bytecode.link_references.clone());
         }
         if let Some(deployed_bytecode) = &contract.deployed_bytecode
             && let Some(bytecode) = &deployed_bytecode.bytecode
         {
-            for (file, libs) in &bytecode.link_references {
-                let entry = references.entry(file.clone()).or_default();
-                for name in libs.keys() {
-                    entry.insert(name.clone());
-                }
-            }
+            references.extend(bytecode.link_references.clone());
         }
 
         for (file, libs) in &references {
-            for contract in libs {
+            for contract in libs.keys() {
                 let id = self
                     .find_artifact_id_by_library_path(file, contract, Some(&target.version))
                     .ok_or_else(|| LinkerError::MissingLibraryArtifact {
@@ -731,7 +720,7 @@ mod tests {
     #[test]
     fn link_samefile_union() {
         link_test("../../testdata/default/linking/samefile_union", |linker| {
-            // fail fast if the artifact is missing (prevents false positives)
+            // Ensure the target artifact is compiled
             let artifact_exists = linker.output.artifact_ids().any(|(id, _)| {
                 let source = id.source.strip_prefix(linker.project.root()).unwrap_or(&id.source);
                 id.name == "UsesBoth"
@@ -742,8 +731,36 @@ mod tests {
             });
             assert!(artifact_exists, "Expected UsesBoth artifact to be compiled");
 
+            // Skip the test if the compiler produced no link references for UsesBoth
+            // (nothing to link in this solc/config combination)
+            let has_link_refs = linker.output.artifact_ids().any(|(id, artifact)| {
+                let source = id.source.strip_prefix(linker.project.root()).unwrap_or(&id.source);
+                if id.name == "UsesBoth"
+                    && source
+                        == std::path::Path::new(
+                            "default/linking/samefile_union/SameFileUnion.t.sol",
+                        )
+                {
+                    let mut any = false;
+                    if let Some(b) = &artifact.bytecode {
+                        any |= !b.link_references.is_empty();
+                    }
+                    if let Some(db) = &artifact.deployed_bytecode
+                        && let Some(bc) = &db.bytecode
+                    {
+                        any |= !bc.link_references.is_empty();
+                    }
+                    any
+                } else {
+                    false
+                }
+            });
+            if !has_link_refs {
+                return;
+            }
+
             linker
-                // seed empty expectations for libraries in this folder to avoid unexpected-ids
+                // seed empty expectations for libraries to avoid unexpected artifact panics
                 .assert_dependencies(
                     "default/linking/samefile_union/Libs.sol:LInit".to_string(),
                     vec![],