fix(join): skip substitution of non-field references in join chains (#…

…9595)

Co-authored-by: Phillip Cloud <417981+cpcloud@users.noreply.github.com>

ibis/expr/tests/test_newrels.py

@@ -1764,3 +1764,68 @@ def test_projections_with_similar_expressions_have_different_names():
     assert b.op().name in fields
 
     assert expr.schema() == ibis.schema({a.op().name: "string", b.op().name: "string"})
+
+
+def test_expr_in_join_projection():
+    t1 = ibis.table({"a": "int64", "b": "string"}, name="t1")
+    t2 = ibis.table({"c": "int64", "b": "string"}, name="t2")
+    t3 = ibis.table({"a": "int64", "d": "int64", "e": "string"}, name="t3")
+    expr = t1.inner_join(t2, "b").select(
+        "a", lit1=1, lit2=2 * t1.a, lit3=_.c - 5, lit4=t2.b.length() / 2.0
+    )
+
+    op = expr.op()
+    assert isinstance(op, ops.JoinChain)
+    assert op.schema == ibis.schema(
+        {
+            "a": "int64",
+            "lit1": "int8",
+            "lit2": "int64",
+            "lit3": "int64",
+            "lit4": "float64",
+        }
+    )
+
+    # simple chain selection
+    expr2 = expr.inner_join(t3, "a").select("a", "d", "lit1", "lit2", "lit3", "lit4")
+    op2 = expr2.op()
+    assert isinstance(op2, ops.JoinChain)
+    assert op2.schema == ibis.schema(
+        {
+            "a": "int64",
+            "d": "int64",
+            "lit1": "int8",
+            "lit2": "int64",
+            "lit3": "int64",
+            "lit4": "float64",
+        }
+    )
+
+    # chain with expressions from all three tables in the join
+    expr = (
+        t1.inner_join(t2, "b")
+        .inner_join(t3, t2.b == t3.e)
+        .select(
+            "a",
+            lit1=1,
+            lit2=2 * t1.a,
+            lit3=_.c - 5,
+            lit4=t2.b.length() / 2.0,
+            lit5=_.e.cast("int") * 3,
+            lit6=t3.d + 1,
+        )
+    )
+
+    op = expr.op()
+    assert isinstance(op, ops.JoinChain)
+    assert op.schema == ibis.schema(
+        {
+            "a": "int64",
+            "lit1": "int8",
+            "lit2": "int64",
+            "lit3": "int64",
+            "lit4": "float64",
+            "lit5": "int64",
+            "lit6": "int64",
+        }
+    )

ibis/expr/types/joins.py

@@ -179,7 +179,11 @@ def prepare_predicates(
         The comparison operation to construct if the input is a pair of
         expression-like objects
     """
-    reverse = {ops.Field(chain, k): v for k, v in chain.values.items()}
+    reverse = {
+        ops.Field(chain, k): v
+        for k, v in chain.values.items()
+        if isinstance(v, ops.Field)
+    }
     deref_right = DerefMap.from_targets(right)
     deref_left = DerefMap.from_targets(chain.tables, extra=reverse)
     deref_both = DerefMap.from_targets([*chain.tables, right], extra=reverse)