tests: check semi_join raises when can't infer on arg

siuba/dply/verbs.py

@@ -1117,7 +1117,7 @@ def semi_join(left, right = None, on = None):
 
         on_cols = list(set(left.columns).intersection(set(right.columns)))
         if not len(on_cols):
-            raise Exception("No joining column specified, and no shared column names")
+            raise Exception("No join column specified, and no shared column names")
 
         warnings.warn("Detected shared columns: %s" % on_cols)
     elif isinstance(on, str):

siuba/sql/verbs.py

@@ -1005,7 +1005,7 @@ def _validate_join_arg_on(on, sql_on = None, lhs = None, rhs = None):
 
             if not on_cols:
                 raise ValueError(
-                    "No on columns specified, or shared column names in join."
+                    "No join column specified, or shared column names in join."
                 )
 
             # trivial dict mapping shared names to themselves

siuba/tests/test_verb_join.py

@@ -182,6 +182,14 @@ def test_semi_join_no_on_arg(backend, df1):
     assert "No on column passed to join." in record[0].message.args[0]
     assert "['ii']" in record[1].message.args[0]
 
+def test_semi_join_no_on_arg_fail(backend, df1):
+    df_ii = backend.load_df(data_frame(ZZ = [1,1]))
+
+    with pytest.raises(Exception) as excinfo:
+        collect(semi_join(df1, df_ii))
+
+    assert "No join column specified" in str(excinfo.value) 
+
 
 def test_basic_anti_join_on_map(backend, df1, df2):
     assert_frame_sort_equal(