Quote ALTER SCHEMA SET values

[jacodegroothydrab]

update_schema builds its literal by hand:

new_value = f"'{new_value}'" if isinstance(new_value, str) else new_value

so an apostrophe ends the string early and the rest arrives as bare SQL:

001003 (42000): SQL compilation error: syntax error line 1 at position 39
unexpected 'comment'. on ALTER SCHEMA MY_DB.MY_SCHEMA SET comment = '...

Any schema comment containing an apostrophe fails to apply. CREATE is unaffected — it already renders through props.quote_value. update_schema was the one branch that hand-rolled its quoting; it now uses quote_value too.

quote_value had the mirror-image gap: $$ is a safe delimiter only while the value doesn't contain $$. It now falls back to a single-quoted literal with ' and backslash doubled in that case.

4 regression tests, all four failing against the current code.

[noel]

snowcap/props.py:36: The fallback for values containing $$ produces a single-quoted literal, but it only escapes apostrophes and backslashes. Actual control characters such as newlines remain unescaped, although Snowflake requires escape sequences inside single-quoted literals. This regresses multiline values that previously worked with dollar quoting.

Please escape control characters such as \n, \r, and \t after escaping backslashes, and add a regression test covering a value containing both $$ and a newline.

Also, please remove or substantially shorten the explanatory comment blocks in snowcap/lifecycle.py and snowcap/props.py; the code and regression tests already document the behavior clearly.

[jacodegroothydrab]

I have addressed your feedback

• Deleted the comment. Duplicate comment risks confusing LLMs if they diverge in the future.
• Escaped control characters
• Add regression tests

Please let me know if you require further changes.

[noel]

snowcap/props.py:35: The fallback now escapes newline, carriage return, and tab, but still emits backspace, form feed, NUL, and other C0 control characters directly into the SQL literal. Snowflake provides escape sequences for these characters, so the fallback is not yet safe for every string accepted by quote_value.

Rather than extending the replacement chain one character at a time, please use the existing json standard-library import to escape control characters, strip its surrounding quotes, and then double apostrophes—for example:

escaped = json.dumps(str(value), ensure_ascii=False)[1:-1].replace("'", "''")

Please add regression coverage containing $$ with \b, \f, and NUL. See Snowflake’s string-literal documentation.

[jacodegroothydrab]

Done — the fallback now uses json.dumps(str(value), ensure_ascii=False)[1:-1].replace("'", "''"), so the whole C0 range is escaped rather than the four characters the chain happened to list. Added regression tests for $$ with \b/\f and with NUL (json emits \u0000, which Snowflake accepts).