From f7efe77ccb5f444dd4bc90a9df1ed95697823a9c Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Sat, 12 Dec 2020 20:46:13 -0800
Subject: [PATCH] Tests for analyze tables

---
 sqlite_utils/cli.py          | 15 ++++--
 tests/test_analyze_tables.py | 91 ++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+), 3 deletions(-)
 create mode 100644 tests/test_analyze_tables.py

diff --git a/sqlite_utils/cli.py b/sqlite_utils/cli.py
index 7e653e6..fe052d2 100644
--- a/sqlite_utils/cli.py
+++ b/sqlite_utils/cli.py
@@ -1361,7 +1361,14 @@ def insert_files(
     required=True,
 )
 @click.argument("tables", nargs=-1)
-@click.option("-c", "--column", "columns", type=str, multiple=True, help="Specific columns to analyze")
+@click.option(
+    "-c",
+    "--column",
+    "columns",
+    type=str,
+    multiple=True,
+    help="Specific columns to analyze",
+)
 @click.option("--save", is_flag=True, help="Save results to _analyze_tables table")
 @load_extension_option
 def analyze_tables(
@@ -1381,11 +1388,13 @@ def analyze_tables(
     for table in tables:
         table_counts[table] = db[table].count
         for column in db[table].columns:
-            if (not columns or column.name in columns):
+            if not columns or column.name in columns:
                 todo.append((table, column.name))
     # Now we now how many we need to do
     for i, (table, column) in enumerate(todo):
-        column_details = db[table].analyze_column(column, total_rows=table_counts[table])
+        column_details = db[table].analyze_column(
+            column, total_rows=table_counts[table]
+        )
         if save:
             db["_analyze_tables"].insert(
                 column_details._asdict(), pk=("table", "column"), replace=True
diff --git a/tests/test_analyze_tables.py b/tests/test_analyze_tables.py
new file mode 100644
index 0000000..8842ee7
--- /dev/null
+++ b/tests/test_analyze_tables.py
@@ -0,0 +1,91 @@
+from sqlite_utils.db import ForeignKey, ColumnDetails
+from sqlite_utils import cli
+from sqlite_utils.utils import OperationalError
+from click.testing import CliRunner
+import pytest
+import sqlite3
+import textwrap
+
+
+@pytest.fixture
+def db_to_analyze(fresh_db):
+    stuff = fresh_db["stuff"]
+    stuff.insert_all(
+        [
+            {"id": 1, "owner": "Terry", "size": 5},
+            {"id": 2, "owner": "Joan", "size": 4},
+            {"id": 3, "owner": "Kumar", "size": 5},
+            {"id": 4, "owner": "Anne", "size": 5},
+            {"id": 5, "owner": "Terry", "size": 5},
+            {"id": 6, "owner": "Joan", "size": 4},
+            {"id": 7, "owner": "Kumar", "size": 5},
+            {"id": 8, "owner": "Joan", "size": 4},
+        ],
+        pk="id",
+    )
+    return fresh_db
+
+
+@pytest.mark.parametrize(
+    "column,expected",
+    [
+        (
+            "id",
+            ColumnDetails(
+                table="stuff",
+                column="id",
+                total_rows=8,
+                num_null=0,
+                num_blank=0,
+                num_distinct=8,
+                most_common=None,
+                least_common=None,
+            ),
+        ),
+        (
+            "owner",
+            ColumnDetails(
+                table="stuff",
+                column="owner",
+                total_rows=8,
+                num_null=0,
+                num_blank=0,
+                num_distinct=4,
+                most_common=[("Joan", 3), ("Terry", 2)],
+                least_common=[("Anne", 1), ("Kumar", 2)],
+            ),
+        ),
+        (
+            "size",
+            ColumnDetails(
+                table="stuff",
+                column="size",
+                total_rows=8,
+                num_null=0,
+                num_blank=0,
+                num_distinct=2,
+                most_common=[(5, 5), (4, 3)],
+                least_common=None,
+            ),
+        ),
+    ],
+)
+def test_analyze_column(db_to_analyze, column, expected):
+    assert db_to_analyze["stuff"].analyze_column(column, common_limit=2) == expected
+
+
+def test_analyze_table(db_to_analyze, tmpdir):
+    path = str(tmpdir / "test.db")
+    db = sqlite3.connect(path)
+    db.executescript("\n".join(db_to_analyze.conn.iterdump()))
+    result = CliRunner().invoke(cli.cli, ["analyze-tables", path])
+    assert (
+        result.output.strip()
+        == textwrap.dedent(
+            """
+    1/3: ColumnDetails(table='stuff', column='id', total_rows=8, num_null=0, num_blank=0, num_distinct=8, most_common=None, least_common=None)
+    2/3: ColumnDetails(table='stuff', column='owner', total_rows=8, num_null=0, num_blank=0, num_distinct=4, most_common=[('Joan', 3), ('Terry', 2), ('Kumar', 2), ('Anne', 1)], least_common=None)
+    3/3: ColumnDetails(table='stuff', column='size', total_rows=8, num_null=0, num_blank=0, num_distinct=2, most_common=[(5, 5), (4, 3)], least_common=None)
+    """
+        ).strip()
+    )