From d504c770030cfc8715437fbb122c3c844c469113 Mon Sep 17 00:00:00 2001
From: Michael Osthege <michael.osthege@outlook.com>
Date: Fri, 2 Dec 2022 15:50:26 +0100
Subject: [PATCH] Give more informative errors for unsupported dtypes

---
 mcbackend/__init__.py                |  2 +-
 mcbackend/backends/clickhouse.py     |  5 +++++
 mcbackend/test_backend_clickhouse.py | 11 +++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/mcbackend/__init__.py b/mcbackend/__init__.py
index c6a43eb..a044c75 100644
--- a/mcbackend/__init__.py
+++ b/mcbackend/__init__.py
@@ -20,4 +20,4 @@
     pass
 
 
-__version__ = "0.2.4"
+__version__ = "0.2.5"
diff --git a/mcbackend/backends/clickhouse.py b/mcbackend/backends/clickhouse.py
index c0b7d35..52311d8 100644
--- a/mcbackend/backends/clickhouse.py
+++ b/mcbackend/backends/clickhouse.py
@@ -49,6 +49,11 @@ def create_runs_table(client: clickhouse_driver.Client):
 
 
 def column_spec_for(var: Variable, is_stat: bool = False):
+    if var.dtype not in CLICKHOUSE_DTYPES:
+        raise KeyError(
+            f"Don't know how to store dtype {var.dtype} "
+            f"of '{var.name}' (is_stat={is_stat}) in ClickHouse."
+        )
     cdt = CLICKHOUSE_DTYPES[var.dtype]
     ndim = len(var.shape)
     for _ in range(ndim):
diff --git a/mcbackend/test_backend_clickhouse.py b/mcbackend/test_backend_clickhouse.py
index 75508aa..275b912 100644
--- a/mcbackend/test_backend_clickhouse.py
+++ b/mcbackend/test_backend_clickhouse.py
@@ -13,6 +13,7 @@
     ClickHouseBackend,
     ClickHouseChain,
     ClickHouseRun,
+    column_spec_for,
     create_chain_table,
 )
 from mcbackend.core import Run, chain_id
@@ -27,6 +28,16 @@
     HAS_REAL_DB = False
 
 
+def test_column_spec_for():
+    assert column_spec_for(Variable("A", "float32", [])) == "`A` Float32"
+    assert column_spec_for(Variable("A", "float32", []), is_stat=True) == "`__stat_A` Float32"
+    assert column_spec_for(Variable("A", "float32", [2])) == "`A` Array(Float32)"
+    assert column_spec_for(Variable("A", "float32", [2, 3])) == "`A` Array(Array(Float32))"
+    with pytest.raises(KeyError, match="float16 of 'A'"):
+        column_spec_for(Variable("A", "float16", []))
+    pass
+
+
 def fully_initialized(
     cbackend: ClickHouseBackend, rmeta: RunMeta, *, nchains: int = 1
 ) -> Tuple[ClickHouseRun, Sequence[ClickHouseChain]]: