Remove import-time string processing from cache backend and models

[Copilot]

The cache backend and models were calling textwrap.dedent() and collapse_spaces() at import time to format SQL strings and expressions, adding unnecessary overhead to module loading.

Changes

• Removed textwrap.dedent import and call from cache.py
• Removed collapse_spaces() function from utils.py
• Replaced all collapse_spaces() calls (18 total) with plain strings across:
  • cache.py: 9 SQL query strings
  • models/expressions.py: 6 SQL expressions
  • models/transforms.py: 1 SQL expression
  • management commands: 2 help text strings
• Replaced dedent() call on create_table_sql with parenthesized string literal containing explicit newlines
• Used # fmt: off and # fmt: on comments to preserve original indentation structure for readability

Before:

from textwrap import dedent
from django_mysql.utils import collapse_spaces

create_table_sql = dedent(
    """\
    CREATE TABLE `{table_name}` (
        cache_key varchar(255) CHARACTER SET utf8 COLLATE utf8_bin
                               NOT NULL PRIMARY KEY,
        ...
    );
"""
)

_add_query = collapse_spaces(
    """
    INSERT INTO {table} (cache_key, value, value_type, expires)
    VALUES (%s, %s, %s, %s)
    ON DUPLICATE KEY UPDATE
        value=IF(expires > @tmp_now:=%s, value, VALUES(value)),
        ...
"""
)

After:

# fmt: off
create_table_sql = (
    "CREATE TABLE `{table_name}` (\n"
    "    cache_key varchar(255) CHARACTER SET utf8 COLLATE utf8_bin\n"
    "                           NOT NULL PRIMARY KEY,\n"
    ...
)
# fmt: on

# fmt: off
_add_query = (
    "INSERT INTO {table} (cache_key, value, value_type, expires) "
    "VALUES (%s, %s, %s, %s) "
    "ON DUPLICATE KEY UPDATE "
        "value=IF(expires > @tmp_now:=%s, value, VALUES(value)), "
        ...
)
# fmt: on

Impact

• Performance: Removed 18 function calls from module import time
• Readability: Original indentation preserved in SQL strings for better readability
• Compatibility: All SQL strings are functionally equivalent (verified by normalization comparison)
• No breaking changes: Works with existing .format() and .splitlines() usage in tests and management commands

Original prompt

remove import-time dedent calls from cache backend, to speed up import time. Use plain strings instead, wrapped in parentheses.

---

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[adamchainz]

@copilot do the same for the collapse_spaces() calls, and see if you can remove collapse_spaces from the repo

[Copilot]

@copilot do the same for the collapse_spaces() calls, and see if you can remove collapse_spaces from the repo

Done! I've replaced all collapse_spaces() calls with plain strings and removed the function from the repo.

Changes made in commit 2af3a00:

• Replaced 9 collapse_spaces() calls in cache.py
• Replaced 6 collapse_spaces() calls in models/expressions.py
• Replaced 1 collapse_spaces() call in models/transforms.py
• Replaced 2 collapse_spaces() calls in management commands
• Removed collapse_spaces function from utils.py
• Removed all imports of collapse_spaces

The SQL strings are functionally equivalent (verified by normalizing and comparing). All linting checks pass. Net reduction: 126 lines of code.

[adamchainz]

@copilot rather than smoosh everything together into one string, preserve the original indentation, even if it needs something like:

# fmt: off
x = (
   "f("
       "x"
    ")"
)
# fmt: on

[Copilot]

@copilot rather than smoosh everything together into one string, preserve the original indentation, even if it needs something like:

...

Done! I've updated all SQL strings to preserve the original indentation using # fmt: off and # fmt: on comments.

Changes in commit c9c88fd:

• Reverted previous changes that smooshed strings together
• Replaced dedent() and collapse_spaces() calls with plain strings
• Preserved original indentation structure in all SQL strings
• Added # fmt: off / # fmt: on markers to prevent formatters from changing indentation
• All SQL strings maintain their original readability

The SQL strings now look like this:

# fmt: off
_add_query = (
    "INSERT INTO {table} (cache_key, value, value_type, expires) "
    "VALUES (%s, %s, %s, %s) "
    "ON DUPLICATE KEY UPDATE "
        "value=IF(expires > @tmp_now:=%s, value, VALUES(value)), "
        "value_type=IF(expires > @tmp_now, value_type, VALUES(value_type)), "
        "expires=IF("
            "expires > @tmp_now, "
            "IFNULL("
                "LEAST(LAST_INSERT_ID(444), NULL), "
                "expires"
            "), "
            "VALUES(expires)"
        ")"
)
# fmt: on