fix: completion of USE ONLY interaces

CHANGELOG.md

@@ -24,6 +24,8 @@
 
 ### Fixed
 
+- Fixed bug where completion of interfaces in USE ONLY would produce the snippet
+  ([#150](https://github.com/fortran-lang/fortls/issues/150))
 - Fixed bug where diagnostic messages were raised for non-existent variables
   ([#173](https://github.com/fortran-lang/fortls/issues/173))
   ([#175](https://github.com/fortran-lang/fortls/issues/175))

fortls/langserver.py

@@ -660,7 +660,7 @@ def build_comp(
                 continue
             #
             name_replace = rename_list[i]
-            if candidate_type == INTERFACE_TYPE_ID:
+            if candidate_type == INTERFACE_TYPE_ID and not line_context == "mod_mems":
                 tmp_list = []
                 if name_replace is None:
                     name_replace = candidate.name

test/test_server_completion.py

@@ -377,3 +377,20 @@ def test_comp_documentation():
     ]
     assert len(exp_results) == len(results[1])
     assert exp_results == results[1]
+
+
+def test_comp_use_only_interface():
+    """Test completion of interfaces when using USE ONLY give the right signature."""
+    string = write_rpc_request(
+        1, "initialize", {"rootPath": str(test_dir / "completion")}
+    )
+    file_path = test_dir / "completion" / "use_only_interface.f90"
+    string += comp_request(file_path, 21, 29)
+    errcode, results = run_request(
+        string,
+    )
+    assert errcode == 0
+    exp_results = [[1, "some_sub", "INTERFACE"]]
+    assert len(exp_results) == len(results) - 1
+    for i, ref in enumerate(exp_results):
+        validate_comp(results[i + 1], ref)

test/test_source/completion/use_only_interface.f90

@@ -0,0 +1,24 @@
+module some_mod
+  implicit none
+  private
+  public :: some_sub
+  interface some_sub
+    module procedure a_subroutine
+    module procedure b_subroutine
+  end interface
+contains
+  subroutine a_subroutine(x)
+    integer, intent(in) :: x
+    write(*,*) 'x = ', x
+  end subroutine a_subroutine
+  subroutine b_subroutine(x, y)
+    integer, intent(in) :: x, y
+    write(*,*) 'x = ', x
+    write(*,*) 'y = ', y
+  end subroutine b_subroutine
+end module some_mod
+
+program main
+    use some_mod, only: some_sub
+    implicit none
+end program main