Fix cross-module generic type alias export and add coverage

tslang/lib/TypeScript/MLIRGenImpl.h

@@ -8336,6 +8336,26 @@ class MLIRGenImpl
                 }
 
                 getGenericTypeAliasMap().insert({namePtr, {typeParameters, typeAliasDeclarationAST->type}});
+
+                // support dynamic loading: like a generic class/function/interface, a
+                // generic type alias has no compiled body or runtime entity at all -
+                // resolution is pure compile-time type substitution
+                // (getTypeByTypeReference/resolveGenericTypeInNamespace call
+                // getType(typeNode, ...) directly on the stored TypeNode, never
+                // re-invoking mlirGen on the whole declaration), unlike
+                // GenericClassInfo/GenericFunctionInfo/GenericInterfaceInfo there is no
+                // dedicated Info struct tracking sourceFile/elementNamespace for this
+                // declaration kind - print inline here instead of adding one, since this
+                // is the only place needing it and there is no "already registered"
+                // early-return branch to retry from (unlike registerGenericClass/
+                // registerGenericFunctionLike/registerGenericInterface):
+                // isAddedToExport's own stage gate is unnecessary too since a given
+                // top-level TypeAliasDeclaration node is visited exactly once per stage,
+                // so a direct stage check is sufficient dedup.
+                if (hasExportModifier && stage == Stages::SourceGeneration)
+                {
+                    addGenericTypeAliasDeclarationToExport(typeAliasDeclarationAST, currentNamespace);
+                }
             }
             else
             {
@@ -10438,6 +10458,36 @@ class MLIRGenImpl
         genericDeclExports << ss.str().str();
     }
 
+    void addGenericTypeAliasDeclarationToExport(TypeAliasDeclaration typeAliasDeclarationAST, NamespaceInfo::TypePtr elementNamespace)
+    {
+        // same bounds-check as addGenericClassDeclarationToExport - a generic type alias
+        // re-declared while re-importing another module's embedded declarations still
+        // carries its own `export` keyword verbatim, but at that point `sourceFile` is
+        // the ambient/outer file, not the "partial" buffer parsePartialStatements
+        // actually parsed this declaration from.
+        auto declEnd = static_cast<size_t>(typeAliasDeclarationAST->_end);
+        if (declEnd > sourceFile->text.length())
+        {
+            return;
+        }
+
+        // like a generic class, a generic type alias has no compiled body for any given
+        // instantiation: resolution is pure compile-time type substitution, done fresh in
+        // whichever module references it. So the FULL original source - type parameters
+        // and the aliased type expression intact, no @dllimport marker - must be
+        // re-exported verbatim for parsePartialStatements to recompile per reference in
+        // the importer.
+        auto declText = convertWideToUTF8(getTextOfNodeFromSourceText(
+            sourceFile->text, typeAliasDeclarationAST.as<Node>(), true));
+
+        SmallVector<char> out;
+        llvm::raw_svector_ostream ss(out);
+        MLIRDeclarationPrinter dp(ss);
+        dp.printGenericClass(elementNamespace, declText);
+
+        genericDeclExports << ss.str().str();
+    }
+
     auto getNamespaceName() -> StringRef
     {
         return currentNamespace->name;

tslang/test/tester/CMakeLists.txt

@@ -885,6 +885,7 @@ add_test(NAME test-compile-export-import-class-static COMMAND test-runner "${PRO
 # See class-generic-declaration-export-fix memory for the full account.
 add_test(NAME test-compile-export-import-class-generic COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/import_class_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_class_generic.ts")
 add_test(NAME test-compile-export-import-function-generic COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/import_function_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_function_generic.ts")
+add_test(NAME test-compile-export-import-type-alias-generic COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/import_type_alias_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_type_alias_generic.ts")
 add_test(NAME test-compile-export-import-class-accessor COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/import_class_accessor.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_class_accessor.ts")
 add_test(NAME test-compile-export-import-class-indexer COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/import_class_indexer.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_class_indexer.ts")
 add_test(NAME test-compile-export-import-interface-indexer COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/import_interface_indexer.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_interface_indexer.ts")
@@ -957,6 +958,7 @@ add_test(NAME test-compile-shared-export-import-class-structural-interface COMMA
 # FIXED: see the matching test-compile-export-import-class-generic comment above (2026-07-22).
 add_test(NAME test-compile-shared-export-import-class-generic COMMAND test-runner -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_class_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_class_generic.ts")
 add_test(NAME test-compile-shared-export-import-function-generic COMMAND test-runner -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_function_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_function_generic.ts")
+add_test(NAME test-compile-shared-export-import-type-alias-generic COMMAND test-runner -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_type_alias_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_type_alias_generic.ts")
 # FIXED (2026-07-22): the -shared declaration-reconstruction path never printed real
 # get/set syntax for a class's accessors, only the underlying get_x/set_x funcOps as
 # ordinary methods - so property-style access ("Class member 'celsius' can't be found")
@@ -1004,6 +1006,7 @@ add_test(NAME test-jit-shared-export-import-class-structural-interface COMMAND t
 # FIXED: see the matching test-compile-export-import-class-generic comment above (2026-07-22).
 add_test(NAME test-jit-shared-export-import-class-generic COMMAND test-runner -jit -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_class_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_class_generic.ts")
 add_test(NAME test-jit-shared-export-import-function-generic COMMAND test-runner -jit -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_function_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_function_generic.ts")
+add_test(NAME test-jit-shared-export-import-type-alias-generic COMMAND test-runner -jit -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_type_alias_generic.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_type_alias_generic.ts")
 # FIXED: see the matching test-compile-shared-export-import-class-accessor comment above (2026-07-22).
 add_test(NAME test-jit-shared-export-import-class-accessor COMMAND test-runner -jit -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_class_accessor.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_class_accessor.ts")
 add_test(NAME test-jit-shared-export-import-class-indexer COMMAND test-runner -jit -shared "${PROJECT_SOURCE_DIR}/test/tester/tests/import_class_indexer.ts" "${PROJECT_SOURCE_DIR}/test/tester/tests/export_class_indexer.ts")

tslang/test/tester/tests/export_type_alias_generic.ts

@@ -0,0 +1,18 @@
+namespace M {
+
+    // Cross-module counterpart to 00type_aliases_in_generics.ts. The
+    // genericTypeAliasMap entry (MLIRGenStore.h) has no dedicated Info struct
+    // (unlike GenericClassInfo/GenericFunctionInfo/GenericInterfaceInfo) - it
+    // was the last unverified item flagged in
+    // decls-cross-module-declaration-mechanism / generic-interface-cross-module-export-fix
+    // as a plausible instance of the same "never routed into declExports" gap.
+
+    export type Box<T> = {
+        value: T;
+    };
+
+    export type Pair<A, B> = {
+        first: A;
+        second: B;
+    };
+}

tslang/test/tester/tests/import_type_alias_generic.ts

@@ -0,0 +1,12 @@
+import './export_type_alias_generic'
+
+function main() {
+    const b: M.Box<number> = { value: 42 };
+    assert(b.value == 42);
+
+    const p: M.Pair<number, string> = { first: 1, second: "one" };
+    assert(p.first == 1);
+    assert(p.second == "one");
+
+    print("done.");
+}