add tests for initializer hints

tests/functional/syntax/modules/test_initializers.py

@@ -1228,3 +1228,67 @@ def use_lib1():
         compile_code(main, input_bundle=input_bundle, output_formats=["annotated_ast_dict"])
         is not None
     )
+
+
+def test_hint_for_missing_initializer_in_list(make_input_bundle):
+    lib1 = """
+counter: uint256
+    """
+    lib3 = """
+counter: uint256
+        """
+    lib2 = """
+import lib1
+import lib3
+
+uses: lib1
+uses: lib3
+
+counter: uint256
+
+@internal
+def foo():
+    lib1.counter += 1
+    lib3.counter += 1
+    """
+    main = """
+import lib1
+import lib2
+import lib3
+
+initializes: lib2[lib1:=lib1]
+initializes: lib1
+initializes: lib3
+    """
+    input_bundle = make_input_bundle({"lib1.vy": lib1, "lib2.vy": lib2, "lib3.vy": lib3})
+    with pytest.raises(InitializerException) as e:
+        compile_code(main, input_bundle=input_bundle)
+    assert e.value._message == "`lib2` uses `lib3`, but it is not initialized with `lib3`"
+    assert e.value._hint == "add `lib3 := lib3` to its initializer list"
+
+
+def test_hint_for_missing_initializer_when_no_import(make_input_bundle):
+    lib1 = """
+counter: uint256
+    """
+    lib2 = """
+import lib1
+
+uses: lib1
+
+counter: uint256
+
+@internal
+def foo():
+    lib1.counter += 1
+    """
+    main = """
+import lib2
+
+initializes: lib2
+    """
+    input_bundle = make_input_bundle({"lib1.vy": lib1, "lib2.vy": lib2})
+    with pytest.raises(InitializerException) as e:
+        compile_code(main, input_bundle=input_bundle)
+    assert e.value._message == "`lib2` uses `lib1`, but it is not initialized with `lib1`"
+    assert e.value._hint == "try importing lib1 first"