fix not-found functions, add tests

tests/functional/codegen/modules/test_exports.py

@@ -2,7 +2,6 @@
 
 from vyper.compiler import compile_code
 from vyper.utils import method_id
-from vyper.exceptions import StructureException
 
 
 def test_simple_export(make_input_bundle, get_contract):
@@ -204,6 +203,7 @@ def _send_transaction(c, method_sig):
         data = method_id(method_sig)
         with tx_failed():
             w3.eth.send_transaction({"to": c.address, "data": data})
+
     return _send_transaction
 
 
@@ -247,7 +247,7 @@ def test_exported_fun_part_of_interface(get_contract, make_input_bundle):
     lib1 = """
 @external
 def bar() -> uint256:
-    return 1 
+    return 1
     """
     lib2 = """
 import lib1
@@ -264,7 +264,9 @@ def foo() -> uint256:
     assert c.foo() == 2
 
 
-def test_imported_module_not_part_of_interface(send_failing_tx_to_signature, get_contract, make_input_bundle):
+def test_imported_module_not_part_of_interface(
+    send_failing_tx_to_signature, get_contract, make_input_bundle
+):
     main = """
 import lib2
 
@@ -273,7 +275,7 @@ def test_imported_module_not_part_of_interface(send_failing_tx_to_signature, get
     lib1 = """
 @external
 def bar() -> uint256:
-    return 1 
+    return 1
     """
     lib2 = """
 import lib1
@@ -288,24 +290,9 @@ def foo() -> uint256:
     send_failing_tx_to_signature(c, "bar()")
 
 
-def test_interface_export_collision(send_failing_tx_to_signature, get_contract, make_input_bundle):
-    main = """
-import lib1
-
-exports: lib1.__interface__
-exports: lib1.bar
-    """
-    lib1 = """
-@external
-def bar() -> uint256:
-    return 1 
-    """
-    input_bundle = make_input_bundle({"lib1.vy": lib1})
-    with pytest.raises(StructureException):
-        get_contract(main, input_bundle=input_bundle)
-
-
-def test_export_unimplemented_interface(send_failing_tx_to_signature, get_contract, make_input_bundle):
+def test_export_unimplemented_interface(
+    send_failing_tx_to_signature, get_contract, make_input_bundle
+):
     ifoo = """
 @external
 def foo() -> uint256:
@@ -331,4 +318,3 @@ def bar() -> uint256:
     c = get_contract(main, input_bundle=input_bundle)
     assert c.foo() == 1
     send_failing_tx_to_signature(c, "bar()")
-

tests/functional/syntax/modules/test_exports.py

@@ -309,3 +309,75 @@ def bar():
     assert e.value.prev_decl.col_offset == 9
     assert e.value.prev_decl.node_source_code == "lib1.foo"
     assert e.value.prev_decl.module_node.path == "main.vy"
+
+
+def test_interface_export_collision(make_input_bundle):
+    main = """
+import lib1
+
+exports: lib1.__interface__
+exports: lib1.bar
+    """
+    lib1 = """
+@external
+def bar() -> uint256:
+    return 1
+    """
+    input_bundle = make_input_bundle({"lib1.vy": lib1})
+    with pytest.raises(StructureException) as e:
+        compile_code(main, input_bundle=input_bundle)
+    assert e.value._message == "already exported!"
+
+
+def test_export_missing_function(make_input_bundle):
+    ifoo = """
+@external
+def do_xyz():
+    ...
+    """
+    lib1 = """
+import ifoo
+
+@external
+@view
+def bar() -> uint256:
+    return 1
+    """
+    main = """
+import lib1
+
+exports: lib1.ifoo
+    """
+    input_bundle = make_input_bundle({"lib1.vy": lib1, "ifoo.vyi": ifoo})
+    with pytest.raises(StructureException) as e:
+        compile_code(main, input_bundle=input_bundle)
+    assert e.value._message == "requested `lib1.ifoo` but `lib1.do_xyz` is not implemented"
+
+
+def test_export_selector_conflict(make_input_bundle):
+    ifoo = """
+@external
+def gsf():
+    ...
+    """
+    lib1 = """
+import ifoo
+
+@external
+def gsf():
+    pass
+
+@external
+@view
+def tgeo() -> uint256:
+    return 1
+    """
+    main = """
+import lib1
+
+exports: (lib1.ifoo, lib1.tgeo)
+    """
+    input_bundle = make_input_bundle({"lib1.vy": lib1, "ifoo.vyi": ifoo})
+    with pytest.raises(StructureException) as e:
+        compile_code(main, input_bundle=input_bundle)
+    assert e.value._message == "Methods produce colliding method ID `0x67e43e43`: gsf(), tgeo()"

vyper/semantics/analysis/module.py

@@ -558,9 +558,19 @@ def visit_ExportsDecl(self, node):
                     raise StructureException("not a valid module!", item.value)
 
                 module_exposed_fns = {fn.name: fn for fn in module_info.typ.exposed_functions}
-                funcs = [
-                    module_exposed_fns[f.name] for f in info.typ.functions.values() if f.is_external
-                ]
+                funcs = []
+                for f in info.typ.functions.values():
+                    # find the implementation of the function in the specific module
+                    impl = module_exposed_fns.get(f.name)
+                    if impl is None:
+                        msg = f"requested `{item.node_source_code}` but"
+                        msg += f" `{item.value.node_source_code}.{f.name}`"
+                        msg += " is not implemented"
+                        raise StructureException(msg, item)
+
+                    # guaranteed by `.exposed_functions`:
+                    assert isinstance(impl, ContractFunctionT) and impl.is_external
+                    funcs.append(impl)
             else:
                 raise StructureException(
                     f"not a function or interface: `{info.typ}`", info.typ.decl_node, item