From d708afc345cd265322ad25b74763b7c19392adbc Mon Sep 17 00:00:00 2001
From: Roland Walker <walker@pobox.com>
Date: Sat, 4 Apr 2026 08:14:11 -0400
Subject: [PATCH] move SQL utilities to sql_utils.py

 * most of the functions in parseutils.py were SQL utilities
 * move four functions from main.py to sql_utils.py
 * create cli_utils.py with the remainder of parseutils.py
---
 AGENTS.md                                     |   3 +-
 changelog.md                                  |   2 +
 mycli/main.py                                 |  56 ++------
 mycli/main_modes/batch.py                     |   2 +-
 mycli/packages/cli_utils.py                   |  12 ++
 mycli/packages/completion_engine.py           |   2 +-
 mycli/packages/prompt_utils.py                |   2 +-
 .../packages/{parseutils.py => sql_utils.py}  |  58 ++++++--
 mycli/packages/tabular_output/sql_format.py   |   2 +-
 mycli/sqlcompleter.py                         |   2 +-
 test/pytests/test_cli_utils.py                |  24 ++++
 test/pytests/test_main.py                     |  13 --
 test/pytests/test_main_regression.py          |  21 +--
 .../{test_parseutils.py => test_sql_utils.py} | 127 ++++++++++++++----
 14 files changed, 199 insertions(+), 127 deletions(-)
 create mode 100644 mycli/packages/cli_utils.py
 rename mycli/packages/{parseutils.py => sql_utils.py} (90%)
 create mode 100644 test/pytests/test_cli_utils.py
 rename test/pytests/{test_parseutils.py => test_sql_utils.py} (85%)

diff --git a/AGENTS.md b/AGENTS.md
index dc4e860f..3920084d 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -27,11 +27,12 @@ A command line client for MySQL with auto-completion and syntax highlighting.
 ├── mycli/packages/                       # application packages
 ├── mycli/packages/batch_utils.py         # utilities for `--batch` mode
 ├── mycli/packages/checkup.py             # implementation of `--checkup` mode
+├── mycli/packages/cli_utils.py           # utilities for parsing CLI arguments
 ├── mycli/packages/completion_engine.py   # implementation of completion suggestions
 ├── mycli/packages/filepaths.py           # utilities for files, including completion suggestions
 ├── mycli/packages/hybrid_redirection.py  # implementation of shell-style redirects
 ├── mycli/packages/paramiko_stub/         # stub in case the Paramiko library is not installed
-├── mycli/packages/parseutils.py          # utilities for parsing SQL statements
+├── mycli/packages/sql_utils.py           # utilities for parsing SQL statements
 ├── mycli/packages/prompt_utils.py        # utilities for confirming on destructive statements
 ├── mycli/packages/ptoolkit/              # extends prompt_toolkit
 ├── mycli/packages/shortcuts.py           # utilities for keyboard shortcuts
diff --git a/changelog.md b/changelog.md
index 2a6e4ad1..4f1f3456 100644
--- a/changelog.md
+++ b/changelog.md
@@ -35,6 +35,8 @@ Internal
 * Move `--checkup` logic to the new `main_modes` with `--batch`.
 * Sort coverage report in tox suite.
 * Skip more tests when a database connection is not present.
+* Move SQL utilities to a new `sql_utils.py`.
+* Move CLI utilities to a new `cli_utils.py`.
 
 
 1.67.1 (2026/03/28)
diff --git a/mycli/main.py b/mycli/main.py
index 7f47e769..f3f8d504 100755
--- a/mycli/main.py
+++ b/mycli/main.py
@@ -87,14 +87,21 @@
 )
 from mycli.main_modes.checkup import main_checkup
 from mycli.packages import special
+from mycli.packages.cli_utils import is_valid_connection_scheme
 from mycli.packages.filepaths import dir_path_exists, guess_socket_location
 from mycli.packages.hybrid_redirection import get_redirect_components, is_redirect_command
-from mycli.packages.parseutils import is_dropping_database, is_valid_connection_scheme
 from mycli.packages.prompt_utils import confirm, confirm_destructive_query
 from mycli.packages.ptoolkit.history import FileHistoryWithTimestamp
 from mycli.packages.special.favoritequeries import FavoriteQueries
 from mycli.packages.special.main import ArgType
 from mycli.packages.special.utils import format_uptime, get_ssl_version, get_uptime, get_warning_count
+from mycli.packages.sql_utils import (
+    is_dropping_database,
+    is_mutating,
+    is_select,
+    need_completion_refresh,
+    need_completion_reset,
+)
 from mycli.packages.sqlresult import SQLResult
 from mycli.packages.string_utils import sanitize_terminal_title
 from mycli.packages.tabular_output import sql_format
@@ -2702,53 +2709,6 @@ def get_password_from_file(password_file: str | None) -> str | None:
     mycli.close()
 
 
-def need_completion_refresh(queries: str) -> bool:
-    """Determines if the completion needs a refresh by checking if the sql
-    statement is an alter, create, drop or change db."""
-    for query in sqlparse.split(queries):
-        try:
-            first_token = query.split()[0]
-            if first_token.lower() in ("alter", "create", "use", "\\r", "\\u", "connect", "drop", "rename"):
-                return True
-        except Exception:
-            continue
-    return False
-
-
-def need_completion_reset(queries: str) -> bool:
-    """Determines if the statement is a database switch such as 'use' or '\\u'.
-    When a database is changed the existing completions must be reset before we
-    start the completion refresh for the new database.
-    """
-    for query in sqlparse.split(queries):
-        try:
-            tokens = query.split()
-            first_token = tokens[0]
-            if first_token.lower() in ("use", "\\u"):
-                return True
-            if first_token.lower() in ("\\r", "connect") and len(tokens) > 1:
-                return True
-        except Exception:
-            continue
-    return False
-
-
-def is_mutating(status_plain: str | None) -> bool:
-    """Determines if the statement is mutating based on the status."""
-    if not status_plain:
-        return False
-
-    mutating = {"insert", "update", "delete", "alter", "create", "drop", "replace", "truncate", "load", "rename"}
-    return status_plain.split(None, 1)[0].lower() in mutating
-
-
-def is_select(status_plain: str | None) -> bool:
-    """Returns true if the first word in status is 'select'."""
-    if not status_plain:
-        return False
-    return status_plain.split(None, 1)[0].lower() == "select"
-
-
 def thanks_picker() -> str:
     import mycli
 
diff --git a/mycli/main_modes/batch.py b/mycli/main_modes/batch.py
index 03b18207..f4b52467 100644
--- a/mycli/main_modes/batch.py
+++ b/mycli/main_modes/batch.py
@@ -12,8 +12,8 @@
 import pymysql
 
 from mycli.packages.batch_utils import statements_from_filehandle
-from mycli.packages.parseutils import is_destructive
 from mycli.packages.prompt_utils import confirm_destructive_query
+from mycli.packages.sql_utils import is_destructive
 
 if TYPE_CHECKING:
     from mycli.main import CliArgs, MyCli
diff --git a/mycli/packages/cli_utils.py b/mycli/packages/cli_utils.py
new file mode 100644
index 00000000..b5e7c5e6
--- /dev/null
+++ b/mycli/packages/cli_utils.py
@@ -0,0 +1,12 @@
+from __future__ import annotations
+
+
+def is_valid_connection_scheme(text: str) -> tuple[bool, str | None]:
+    # exit early if the text does not resemble a DSN URI
+    if "://" not in text:
+        return False, None
+    scheme = text.split("://")[0]
+    if scheme not in ("mysql", "mysqlx", "tcp", "socket", "ssh"):
+        return False, scheme
+    else:
+        return True, None
diff --git a/mycli/packages/completion_engine.py b/mycli/packages/completion_engine.py
index 0d69701e..f623a38c 100644
--- a/mycli/packages/completion_engine.py
+++ b/mycli/packages/completion_engine.py
@@ -6,9 +6,9 @@
 import sqlparse
 from sqlparse.sql import Comparison, Identifier, Token, Where
 
-from mycli.packages.parseutils import extract_tables, find_prev_keyword, last_word
 from mycli.packages.special.main import COMMANDS as SPECIAL_COMMANDS
 from mycli.packages.special.main import parse_special_command
+from mycli.packages.sql_utils import extract_tables, find_prev_keyword, last_word
 
 sqlparse.engine.grouping.MAX_GROUPING_DEPTH = None  # type: ignore[assignment]
 sqlparse.engine.grouping.MAX_GROUPING_TOKENS = None  # type: ignore[assignment]
diff --git a/mycli/packages/prompt_utils.py b/mycli/packages/prompt_utils.py
index 68c468f6..fa0f0537 100644
--- a/mycli/packages/prompt_utils.py
+++ b/mycli/packages/prompt_utils.py
@@ -2,7 +2,7 @@
 
 import click
 
-from mycli.packages.parseutils import is_destructive
+from mycli.packages.sql_utils import is_destructive
 
 
 class ConfirmBoolParamType(click.ParamType):
diff --git a/mycli/packages/parseutils.py b/mycli/packages/sql_utils.py
similarity index 90%
rename from mycli/packages/parseutils.py
rename to mycli/packages/sql_utils.py
index 53b96823..8edb5744 100644
--- a/mycli/packages/parseutils.py
+++ b/mycli/packages/sql_utils.py
@@ -23,17 +23,6 @@
 }
 
 
-def is_valid_connection_scheme(text: str) -> tuple[bool, str | None]:
-    # exit early if the text does not resemble a DSN URI
-    if "://" not in text:
-        return False, None
-    scheme = text.split("://")[0]
-    if scheme not in ("mysql", "mysqlx", "tcp", "socket", "ssh"):
-        return False, scheme
-    else:
-        return True, None
-
-
 def last_word(
     text: str,
     include: Literal[
@@ -433,3 +422,50 @@ def normalize_db_name(db: str) -> str:
             if database_token is not None and normalize_db_name(database_token.get_name()) == dbname:
                 result = keywords[0].normalized == "DROP"
     return result
+
+
+def need_completion_refresh(queries: str) -> bool:
+    """Determines if the completion needs a refresh by checking if the sql
+    statement is an alter, create, drop or change db."""
+    for query in sqlparse.split(queries):
+        try:
+            first_token = query.split()[0]
+            if first_token.lower() in ("alter", "create", "use", "\\r", "\\u", "connect", "drop", "rename"):
+                return True
+        except Exception:
+            continue
+    return False
+
+
+def need_completion_reset(queries: str) -> bool:
+    """Determines if the statement is a database switch such as 'use' or '\\u'.
+    When a database is changed the existing completions must be reset before we
+    start the completion refresh for the new database.
+    """
+    for query in sqlparse.split(queries):
+        try:
+            tokens = query.split()
+            first_token = tokens[0]
+            if first_token.lower() in ("use", "\\u"):
+                return True
+            if first_token.lower() in ("\\r", "connect") and len(tokens) > 1:
+                return True
+        except Exception:
+            continue
+    return False
+
+
+def is_mutating(status_plain: str | None) -> bool:
+    """Determines if the statement is mutating based on the status."""
+    if not status_plain:
+        return False
+
+    mutating = {"insert", "update", "delete", "alter", "create", "drop", "replace", "truncate", "load", "rename"}
+    return status_plain.split(None, 1)[0].lower() in mutating
+
+
+def is_select(status_plain: str | None) -> bool:
+    """Returns true if the first word in status is 'select'."""
+    if not status_plain:
+        return False
+    return status_plain.split(None, 1)[0].lower() == "select"
diff --git a/mycli/packages/tabular_output/sql_format.py b/mycli/packages/tabular_output/sql_format.py
index 7583c339..31def8e1 100644
--- a/mycli/packages/tabular_output/sql_format.py
+++ b/mycli/packages/tabular_output/sql_format.py
@@ -6,7 +6,7 @@
 
 from cli_helpers.tabular_output import TabularOutputFormatter
 
-from mycli.packages.parseutils import extract_tables_from_complete_statements
+from mycli.packages.sql_utils import extract_tables_from_complete_statements
 
 supported_formats = (
     "sql-insert",
diff --git a/mycli/sqlcompleter.py b/mycli/sqlcompleter.py
index e7ee2370..c0f669c8 100644
--- a/mycli/sqlcompleter.py
+++ b/mycli/sqlcompleter.py
@@ -13,10 +13,10 @@
 
 from mycli.packages.completion_engine import is_inside_quotes, suggest_type
 from mycli.packages.filepaths import complete_path, parse_path, suggest_path
-from mycli.packages.parseutils import extract_columns_from_select, extract_tables, last_word
 from mycli.packages.special import llm
 from mycli.packages.special.favoritequeries import FavoriteQueries
 from mycli.packages.special.main import COMMANDS as SPECIAL_COMMANDS
+from mycli.packages.sql_utils import extract_columns_from_select, extract_tables, last_word
 
 _logger = logging.getLogger(__name__)
 _CASE_CHANGE_PAT = re.compile('(?<=[a-z])(?=[A-Z])|(?<=[A-Z])(?=[A-Z][a-z])')
diff --git a/test/pytests/test_cli_utils.py b/test/pytests/test_cli_utils.py
new file mode 100644
index 00000000..7875e2e3
--- /dev/null
+++ b/test/pytests/test_cli_utils.py
@@ -0,0 +1,24 @@
+# type: ignore
+
+import pytest
+
+from mycli.packages.cli_utils import (
+    is_valid_connection_scheme,
+)
+
+
+@pytest.mark.parametrize(
+    ('text', 'is_valid', 'invalid_scheme'),
+    [
+        ('localhost', False, None),
+        ('mysql://user@localhost/db', True, None),
+        ('mysqlx://user@localhost/db', True, None),
+        ('tcp://localhost:3306', True, None),
+        ('socket:///tmp/mysql.sock', True, None),
+        ('ssh://user@example.com', True, None),
+        ('postgres://user@localhost/db', False, 'postgres'),
+        ('http://example.com', False, 'http'),
+    ],
+)
+def test_is_valid_connection_scheme(text, is_valid, invalid_scheme):
+    assert is_valid_connection_scheme(text) == (is_valid, invalid_scheme)
diff --git a/test/pytests/test_main.py b/test/pytests/test_main.py
index 92e29a45..67889761 100644
--- a/test/pytests/test_main.py
+++ b/test/pytests/test_main.py
@@ -21,7 +21,6 @@
     TEST_DATABASE,
 )
 from mycli.main import EMPTY_PASSWORD_FLAG_SENTINEL, MyCli, click_entrypoint, thanks_picker
-from mycli.packages.parseutils import is_valid_connection_scheme
 import mycli.packages.special
 from mycli.packages.special.main import COMMANDS as SPECIAL_COMMANDS
 from mycli.packages.sqlresult import SQLResult
@@ -143,18 +142,6 @@ def test_select_from_empty_table(executor):
     assert expected in result.output
 
 
-@dbtest
-def test_is_valid_connection_scheme_valid(executor, capsys):
-    is_valid, scheme = is_valid_connection_scheme(f"mysql://test@{DEFAULT_HOST}:{DEFAULT_PORT}/dev")
-    assert is_valid
-
-
-@dbtest
-def test_is_valid_connection_scheme_invalid(executor, capsys):
-    is_valid, scheme = is_valid_connection_scheme(f"nope://test@{DEFAULT_HOST}:{DEFAULT_PORT}/dev")
-    assert not is_valid
-
-
 def test_filtered_sys_argv_maps_single_dash_h_to_help(monkeypatch):
     import mycli.main
 
diff --git a/test/pytests/test_main_regression.py b/test/pytests/test_main_regression.py
index 33f9a6c2..377cd59d 100644
--- a/test/pytests/test_main_regression.py
+++ b/test/pytests/test_main_regression.py
@@ -1329,10 +1329,6 @@ def cursor(self) -> PromptCursor:
     prompt = main.MyCli.get_prompt(cli, r'\H|\y|\Y|\T|\w|\W', 1)
     assert prompt == '127.0.0.1|123|uptime:123|TLSv1.3|7|7'
 
-    monkeypatch.setattr(main.sqlparse, 'split', lambda text: [None])
-    assert main.need_completion_refresh('sql') is False
-    assert main.need_completion_reset('sql') is False
-
 
 def test_format_sqlresult_string_paths_and_close_and_title_early_returns(monkeypatch: pytest.MonkeyPatch) -> None:
     cli = make_bare_mycli()
@@ -1484,7 +1480,6 @@ def test_filtered_sys_argv_covers_help_and_passthrough(monkeypatch: pytest.Monke
     assert main.filtered_sys_argv() == ['--help']
     monkeypatch.setattr(main.sys, 'argv', ['mycli', '-h', 'db.example'])
     assert main.filtered_sys_argv() == ['-h', 'db.example']
-    assert main.need_completion_refresh('') is False
 
 
 def test_completion_helpers_title_helpers_thanks_tips_and_read_ssh_config(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
@@ -1526,21 +1521,6 @@ def test_completion_helpers_title_helpers_thanks_tips_and_read_ssh_config(monkey
     assert list(main.MyCli.get_completions(cli, 'select', 6)) == ['done']
     assert entered_lock['count'] >= 2
 
-    monkeypatch.setattr(main.sqlparse, 'split', lambda text: ['alter table t', 'broken'])
-    assert main.need_completion_refresh('sql') is True
-    monkeypatch.setattr(main.sqlparse, 'split', lambda text: [''])
-    assert main.need_completion_refresh('sql') is False
-    monkeypatch.setattr(main.sqlparse, 'split', lambda text: ['use db'])
-    assert main.need_completion_reset('use db') is True
-    monkeypatch.setattr(main.sqlparse, 'split', lambda text: ['connect db'])
-    assert main.need_completion_reset('connect db') is True
-    monkeypatch.setattr(main.sqlparse, 'split', lambda text: ['select 1'])
-    assert main.need_completion_reset('select 1') is False
-    assert main.is_mutating('INSERT 1') is True
-    assert main.is_mutating(None) is False
-    assert main.is_select('SELECT 1') is True
-    assert main.is_select(None) is False
-
     class FakeResource:
         def __init__(self, text: str | None) -> None:
             self.text = text
@@ -2725,6 +2705,7 @@ def run(self, text: str) -> Iterator[SQLResult]:
     monkeypatch.setattr(main, 'need_completion_refresh', lambda text: text == 'dropdb')
     monkeypatch.setattr(main, 'need_completion_reset', lambda text: True)
     monkeypatch.setattr(main, 'is_dropping_database', lambda text, dbname: text == 'dropdb')
+
     main.MyCli.run_cli(cli)
     assert reconnect_calls == ['', '']
     assert any('bad op' in line for line in echoes)
diff --git a/test/pytests/test_parseutils.py b/test/pytests/test_sql_utils.py
similarity index 85%
rename from test/pytests/test_parseutils.py
rename to test/pytests/test_sql_utils.py
index df53c06c..81619127 100644
--- a/test/pytests/test_parseutils.py
+++ b/test/pytests/test_sql_utils.py
@@ -5,8 +5,8 @@
 from sqlparse.sql import Identifier, IdentifierList, Token, TokenList
 from sqlparse.tokens import DML, Keyword, Punctuation
 
-from mycli.packages import parseutils
-from mycli.packages.parseutils import (
+from mycli.packages import sql_utils
+from mycli.packages.sql_utils import (
     extract_columns_from_select,
     extract_from_part,
     extract_table_identifiers,
@@ -16,9 +16,12 @@
     get_last_select,
     is_destructive,
     is_dropping_database,
+    is_mutating,
+    is_select,
     is_subselect,
-    is_valid_connection_scheme,
     last_word,
+    need_completion_refresh,
+    need_completion_reset,
     queries_start_with,
     query_has_where_clause,
     query_is_single_table_update,
@@ -175,23 +178,6 @@ def test_queries_start_with():
     assert queries_start_with(sql, ['delete', 'update']) is False
 
 
-@pytest.mark.parametrize(
-    ('text', 'is_valid', 'invalid_scheme'),
-    [
-        ('localhost', False, None),
-        ('mysql://user@localhost/db', True, None),
-        ('mysqlx://user@localhost/db', True, None),
-        ('tcp://localhost:3306', True, None),
-        ('socket:///tmp/mysql.sock', True, None),
-        ('ssh://user@example.com', True, None),
-        ('postgres://user@localhost/db', False, 'postgres'),
-        ('http://example.com', False, 'http'),
-    ],
-)
-def test_is_valid_connection_scheme(text, is_valid, invalid_scheme):
-    assert is_valid_connection_scheme(text) == (is_valid, invalid_scheme)
-
-
 @pytest.mark.parametrize(
     ('text', 'include', 'expected'),
     [
@@ -378,7 +364,7 @@ def test_query_is_single_table_update(sql, is_single_table):
 
 
 def test_extract_columns_from_select_handles_falsey_last_select(monkeypatch):
-    monkeypatch.setattr(parseutils, 'get_last_select', lambda _parsed: [])
+    monkeypatch.setattr(sql_utils, 'get_last_select', lambda _parsed: [])
     assert extract_columns_from_select('select 1') == []
 
 
@@ -388,7 +374,7 @@ def get_real_name(self):
             return 'column_name'
 
     monkeypatch.setattr(
-        parseutils,
+        sql_utils,
         'get_last_select',
         lambda _parsed: TokenList([Token(DML, 'SELECT'), SingleIdentifier([])]),
     )
@@ -402,7 +388,7 @@ def get_identifiers(self):
             return [object()]
 
     monkeypatch.setattr(
-        parseutils,
+        sql_utils,
         'get_last_select',
         lambda _parsed: TokenList([Token(DML, 'SELECT'), WeirdIdentifierList([])]),
     )
@@ -412,7 +398,7 @@ def get_identifiers(self):
 
 def test_extract_columns_from_select_stops_at_keyword_before_collecting_columns(monkeypatch):
     monkeypatch.setattr(
-        parseutils,
+        sql_utils,
         'get_last_select',
         lambda _parsed: TokenList([Token(DML, 'SELECT'), Token(Keyword, 'FROM')]),
     )
@@ -421,7 +407,7 @@ def test_extract_columns_from_select_stops_at_keyword_before_collecting_columns(
 
 
 def test_extract_tables_from_complete_statements_returns_empty_for_falsey_rough_parse(monkeypatch):
-    monkeypatch.setattr(parseutils.sqlparse, 'parse', lambda _sql: [])
+    monkeypatch.setattr(sql_utils.sqlparse, 'parse', lambda _sql: [])
 
     assert extract_tables_from_complete_statements('select * from t') == []
 
@@ -441,14 +427,14 @@ class FakeStatement:
         def find_all(self, _table_type):
             return [FakeIdentifier()]
 
-    monkeypatch.setattr(parseutils.sqlparse, 'parse', lambda _sql: ['stmt'])
-    monkeypatch.setattr(parseutils.sqlglot, 'parse_one', lambda *_args, **_kwargs: FakeStatement())
+    monkeypatch.setattr(sql_utils.sqlparse, 'parse', lambda _sql: ['stmt'])
+    monkeypatch.setattr(sql_utils.sqlglot, 'parse_one', lambda *_args, **_kwargs: FakeStatement())
 
     assert extract_tables_from_complete_statements('with cte as (select 1) select * from cte') == []
 
 
 def test_query_is_single_table_update_returns_false_when_parse_result_is_empty(monkeypatch):
-    monkeypatch.setattr(parseutils.sqlparse, 'parse', lambda _sql: [])
+    monkeypatch.setattr(sql_utils.sqlparse, 'parse', lambda _sql: [])
 
     assert query_is_single_table_update('update test set x = 1') is False
 
@@ -479,7 +465,7 @@ def test_is_destructive_update_without_where_clause():
 
 
 def test_is_destructive_skips_empty_split_queries(monkeypatch):
-    monkeypatch.setattr(parseutils.sqlparse, 'split', lambda _queries: ['', ''])
+    monkeypatch.setattr(sql_utils.sqlparse, 'split', lambda _queries: ['', ''])
 
     assert is_destructive(['drop'], 'ignored') is False
 
@@ -521,3 +507,86 @@ def test_is_dropping_database(sql, dbname, is_dropping):
 
 def test_is_dropping_database_skips_statements_without_enough_keywords():
     assert is_dropping_database('drop foo', 'foo') is False
+
+
+@pytest.mark.parametrize(
+    ('queries', 'expected'),
+    [
+        ('select 1;', False),
+        ('alter table foo add column bar int;', True),
+        ('create table foo (id int);', True),
+        ('use foo;', True),
+        ('\\r foo localhost root', True),
+        ('\\u foo', True),
+        ('connect foo localhost root', True),
+        ('drop table foo;', True),
+        ('rename table foo to bar;', True),
+    ],
+)
+def test_need_completion_refresh(queries, expected):
+    assert need_completion_refresh(queries) is expected
+
+
+def test_need_completion_refresh_ignores_queries_that_fail_to_split(monkeypatch):
+    class BrokenQuery:
+        def split(self):
+            raise RuntimeError('broken')
+
+    monkeypatch.setattr(sql_utils.sqlparse, 'split', lambda _queries: [BrokenQuery(), 'select 1;'])
+
+    assert need_completion_refresh('ignored') is False
+
+
+@pytest.mark.parametrize(
+    ('queries', 'expected'),
+    [
+        ('select 1;', False),
+        ('use foo;', True),
+        ('\\u foo', True),
+        ('\\r', False),
+        ('\\r foo localhost root', True),
+        ('connect', False),
+        ('connect foo localhost root', True),
+    ],
+)
+def test_need_completion_reset(queries, expected):
+    assert need_completion_reset(queries) is expected
+
+
+def test_need_completion_reset_ignores_queries_that_fail_to_split(monkeypatch):
+    class BrokenQuery:
+        def split(self):
+            raise RuntimeError('broken')
+
+    monkeypatch.setattr(sql_utils.sqlparse, 'split', lambda _queries: [BrokenQuery(), 'select 1;'])
+
+    assert need_completion_reset('ignored') is False
+
+
+@pytest.mark.parametrize(
+    ('status_plain', 'expected'),
+    [
+        (None, False),
+        ('', False),
+        ('SELECT 1', False),
+        ('INSERT 1', True),
+        ('update 3', True),
+        ('rename table', True),
+    ],
+)
+def test_is_mutating(status_plain, expected):
+    assert is_mutating(status_plain) is expected
+
+
+@pytest.mark.parametrize(
+    ('status_plain', 'expected'),
+    [
+        (None, False),
+        ('', False),
+        ('SELECT 1', True),
+        ('select rows', True),
+        ('UPDATE 1', False),
+    ],
+)
+def test_is_select(status_plain, expected):
+    assert is_select(status_plain) is expected