fix: follow dependencies when looking for a struct (#3405)

Co-authored-by: kevaundray <kevtheappdev@gmail.com>

compiler/noirc_frontend/src/hir/mod.rs

@@ -7,7 +7,7 @@ pub mod type_check;
 #[cfg(feature = "aztec")]
 pub(crate) mod aztec_library;
 
-use crate::graph::{CrateGraph, CrateId, Dependency};
+use crate::graph::{CrateGraph, CrateId};
 use crate::hir_def::function::FuncMeta;
 use crate::node_interner::{FuncId, NodeInterner, StructId};
 use def_map::{Contract, CrateDefMap};
@@ -119,18 +119,35 @@ impl Context {
         if &module_id.krate == crate_id {
             module_path
         } else {
-            let crate_name = &self.crate_graph[crate_id]
-                .dependencies
-                .iter()
-                .find_map(|dep| match dep {
-                    Dependency { name, crate_id } if crate_id == &module_id.krate => Some(name),
-                    _ => None,
-                })
+            let crates = self
+                .find_dependencies(crate_id, &module_id.krate)
                 .expect("The Struct was supposed to be defined in a dependency");
-            format!("{crate_name}::{module_path}")
+            crates.join("::") + "::" + &module_path
         }
     }
 
+    /// Recursively walks down the crate dependency graph from crate_id until we reach requested crate
+    /// This is needed in case a library (lib1) re-export a structure defined in another library (lib2)
+    /// In that case, we will get [lib1,lib2] when looking for a struct defined in lib2,
+    /// re-exported by lib1 and used by the main crate.
+    /// Returns the path from crate_id to target_crate_id
+    fn find_dependencies(
+        &self,
+        crate_id: &CrateId,
+        target_crate_id: &CrateId,
+    ) -> Option<Vec<String>> {
+        for dep in &self.crate_graph[crate_id].dependencies {
+            if &dep.crate_id == target_crate_id {
+                return Some(vec![dep.name.to_string()]);
+            }
+            if let Some(mut path) = self.find_dependencies(&dep.crate_id, target_crate_id) {
+                path.insert(0, dep.name.to_string());
+                return Some(path);
+            }
+        }
+        None
+    }
+
     pub fn function_meta(&self, func_id: &FuncId) -> FuncMeta {
         self.def_interner.function_meta(func_id)
     }

tooling/nargo_cli/tests/compile_success_empty/workspace_reexport_bug/Nargo.toml

@@ -0,0 +1,7 @@
+[workspace]
+members = [
+    "library", 
+    "library2",
+    "binary"
+]
+default-member = "binary"

tooling/nargo_cli/tests/compile_success_empty/workspace_reexport_bug/binary/Nargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "binary"
+type = "bin"
+authors = [""]
+[dependencies]
+library = { path = "../library" }

tooling/nargo_cli/tests/compile_success_empty/workspace_reexport_bug/binary/src/main.nr

@@ -0,0 +1,2 @@
+use dep::library::ReExportMeFromAnotherLib;
+fn main(_x : ReExportMeFromAnotherLib) {}

tooling/nargo_cli/tests/compile_success_empty/workspace_reexport_bug/library/Nargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "library"
+type = "lib"
+authors = [""]
+
+[dependencies]
+library2 =  { path = "../library2"}

tooling/nargo_cli/tests/compile_success_empty/workspace_reexport_bug/library/src/lib.nr

@@ -0,0 +1,2 @@
+// Re-export 
+use dep::library2::ReExportMeFromAnotherLib;

tooling/nargo_cli/tests/compile_success_empty/workspace_reexport_bug/library2/Nargo.toml

@@ -0,0 +1,5 @@
+[package]
+name = "library"
+type = "lib"
+authors = [""]
+[dependencies]

tooling/nargo_cli/tests/compile_success_empty/workspace_reexport_bug/library2/src/lib.nr

@@ -0,0 +1,5 @@
+// When we re-export this type from another library and then use it in
+// main, we get a panic
+struct ReExportMeFromAnotherLib {
+    x : Field,
+}