fix: nested module resolution bug

crates/erg_compiler/build_package.rs

@@ -149,7 +149,7 @@ pub enum ResolveError {
     },
 }
 
-pub type ResolveResult<T> = Result<T, ResolveError>;
+pub type ResolveResult<T> = Result<T, Vec<ResolveError>>;
 
 /// Resolve dependencies and build a package.
 /// This object should be a singleton.
@@ -387,7 +387,8 @@ impl<ASTBuilder: ASTBuildable, HIRBuilder: Buildable>
     ) -> Result<CompleteArtifact, IncompleteArtifact> {
         let cfg = self.cfg.copy();
         log!(info "Start dependency resolution process");
-        let _ = self.resolve(&mut ast, &cfg);
+        let res = self.resolve(&mut ast, &cfg);
+        debug_assert!(res.is_ok(), "{:?}", res.unwrap_err());
         log!(info "Dependency resolution process completed");
         log!("graph:\n{}", self.shared.graph.display());
         if self.parse_errors.errors.is_empty() {
@@ -411,47 +412,55 @@ impl<ASTBuilder: ASTBuildable, HIRBuilder: Buildable>
     /// Analyze ASTs and make the dependencies graph.
     /// If circular dependencies are found, inline submodules to eliminate the circularity.
     fn resolve(&mut self, ast: &mut AST, cfg: &ErgConfig) -> ResolveResult<()> {
-        let mut result = Ok(());
+        let mut errs = vec![];
         for chunk in ast.module.iter_mut() {
             if let Err(err) = self.check_import(chunk, cfg) {
-                result = Err(err);
+                errs.extend(err);
             }
         }
-        result
+        if errs.is_empty() {
+            Ok(())
+        } else {
+            Err(errs)
+        }
     }
 
     fn check_import(&mut self, expr: &mut Expr, cfg: &ErgConfig) -> ResolveResult<()> {
-        let mut result = Ok(());
+        let mut errs = vec![];
         match expr {
             Expr::Call(call) if call.additional_operation().is_some_and(|op| op.is_import()) => {
                 if let Err(err) = self.register(expr, cfg) {
-                    result = Err(err);
+                    errs.extend(err);
                 }
             }
             Expr::Def(def) => {
                 for expr in def.body.block.iter_mut() {
                     if let Err(err) = self.check_import(expr, cfg) {
-                        result = Err(err);
+                        errs.extend(err);
                     }
                 }
             }
             Expr::Dummy(chunks) => {
                 for chunk in chunks.iter_mut() {
                     if let Err(err) = self.check_import(chunk, cfg) {
-                        result = Err(err);
+                        errs.extend(err);
                     }
                 }
             }
             Expr::Compound(chunks) => {
                 for chunk in chunks.iter_mut() {
                     if let Err(err) = self.check_import(chunk, cfg) {
-                        result = Err(err);
+                        errs.extend(err);
                     }
                 }
             }
             _ => {}
         }
-        result
+        if errs.is_empty() {
+            Ok(())
+        } else {
+            Err(errs)
+        }
     }
 
     fn analysis_in_progress(path: &Path) -> bool {
@@ -588,10 +597,10 @@ impl<ASTBuilder: ASTBuildable, HIRBuilder: Buildable>
             .is_err()
         {
             self.submodules.push(from_path.clone());
-            return Err(ResolveError::CycleDetected {
+            return Err(vec![ResolveError::CycleDetected {
                 path: import_path,
                 submod_input: cfg.input.clone(),
-            });
+            }]);
         }
         if import_path == from_path
             || self.submodules.contains(&import_path)
@@ -627,19 +636,20 @@ impl<ASTBuilder: ASTBuildable, HIRBuilder: Buildable>
                 }
             }
         };
-        if let Err(ResolveError::CycleDetected { path, submod_input }) =
-            self.resolve(&mut ast, &import_cfg)
-        {
+        if let Err(mut errs) = self.resolve(&mut ast, &import_cfg) {
             *expr = Expr::InlineModule(InlineModule::new(
                 Input::file(import_path.to_path_buf()),
                 ast,
                 call.clone(),
             ));
-            if path != from_path {
-                return Err(ResolveError::CycleDetected { path, submod_input });
-            } else {
-                self.cyclic.push(path);
+            errs.retain(|err| match err {
+                ResolveError::CycleDetected { path, .. } => path != &from_path,
+            });
+            if errs.is_empty() {
+                self.cyclic.push(from_path);
                 return Ok(());
+            } else {
+                return Err(errs);
             }
         }
         let prev = self.asts.insert(import_path, (__name__.clone(), ast));

crates/erg_compiler/context/inquire.rs

@@ -51,10 +51,12 @@ pub enum SubstituteResult {
 }
 
 impl Context {
+    /// Returns `true` if the module is being inspected, or has been inspected
     pub(crate) fn mod_registered(&self, path: &NormalizedPathBuf) -> bool {
         (self.shared.is_some() && self.promises().is_registered(path)) || self.mod_cached(path)
     }
 
+    /// Returns `true` if the module has been inspected
     pub(crate) fn mod_cached(&self, path: &Path) -> bool {
         self.mod_cache().get(path).is_some() || self.py_mod_cache().get(path).is_some()
     }

crates/erg_compiler/context/mod.rs

@@ -415,7 +415,9 @@ impl From<&Def> for ContextKind {
             DefKind::Class | DefKind::Inherit => Self::Class,
             DefKind::Trait | DefKind::Subsume => Self::Trait,
             DefKind::StructuralTrait => Self::StructuralTrait,
-            DefKind::ErgImport | DefKind::PyImport | DefKind::RsImport => Self::Module,
+            DefKind::ErgImport | DefKind::PyImport | DefKind::RsImport | DefKind::InlineModule => {
+                Self::Module
+            }
             DefKind::Other => {
                 if def.is_subr() {
                     if def.sig.ident().unwrap().is_procedural() {

crates/erg_compiler/lower.rs

@@ -10,7 +10,7 @@ use erg_common::dict;
 use erg_common::dict::Dict;
 use erg_common::error::{Location, MultiErrorDisplay};
 use erg_common::fresh::FreshNameGenerator;
-use erg_common::pathutil::mod_name;
+use erg_common::pathutil::{mod_name, NormalizedPathBuf};
 use erg_common::set;
 use erg_common::set::Set;
 use erg_common::traits::{ExitStatus, Locational, NoTypeDisplay, Runnable, Stream};
@@ -2981,7 +2981,10 @@ impl<A: ASTBuildable> GenericASTLowerer<A> {
         expect: Option<&Type>,
     ) -> hir::Call {
         log!(info "entered {}", fn_name!());
-        let path = inline.input.path().to_path_buf();
+        let path = NormalizedPathBuf::from(inline.input.path().to_path_buf());
+        if self.module.context.mod_cached(&path) {
+            return self.lower_call(inline.import, expect);
+        }
         let parent = self.get_mod_ctx().context.get_module().unwrap().clone();
         let mod_ctx = ModuleContext::new(parent, dict! {});
         let mod_name = mod_name(&path);

crates/erg_compiler/module/graph.rs

@@ -277,6 +277,10 @@ impl SharedModuleGraph {
         self.0.borrow_mut().sort()
     }
 
+    pub fn entries(&self) -> Set<NormalizedPathBuf> {
+        self.0.borrow().iter().map(|n| n.id.clone()).collect()
+    }
+
     pub fn initialize(&self) {
         self.0.borrow_mut().initialize();
     }

crates/erg_compiler/ty/mod.rs

@@ -1236,7 +1236,7 @@ impl LimitedDisplay for Type {
             }
             Self::Poly { name, params } => {
                 write!(f, "{name}(")?;
-                if self.is_module() {
+                if !DEBUG_MODE && self.is_module() {
                     // Module("path/to/module.er") -> Module("module.er")
                     let name = params.first().unwrap().to_string_unabbreviated();
                     let name = name.replace("__init__.d.er", "").replace("__init__.er", "");

crates/erg_parser/ast.rs

@@ -5522,6 +5522,7 @@ pub enum DefKind {
     PyImport,
     RsImport,
     Patch,
+    InlineModule,
     /// type alias included
     Other,
 }
@@ -5556,6 +5557,10 @@ impl DefKind {
         self.is_erg_import() || self.is_py_import() || self.is_rs_import()
     }
 
+    pub fn is_inline_module(&self) -> bool {
+        matches!(self, Self::InlineModule)
+    }
+
     pub const fn is_other(&self) -> bool {
         matches!(self, Self::Other)
     }
@@ -5607,6 +5612,7 @@ impl DefBody {
                 Some("rsimport") => DefKind::RsImport,
                 _ => DefKind::Other,
             },
+            Expr::InlineModule(_) => DefKind::InlineModule,
             _ => DefKind::Other,
         }
     }