Datasette had two tracing systems since the OpenTelemetry spans landed. The
hand-rolled one measures the wrong thing - issue 1730, open since 2022, is
about exactly that - and it cannot be rebuilt on top of the new spans without
core owning a TracerProvider, which is the one thing the OTel design refuses
to do. Rather than carry duplicate instrumentation on the db.execute() hot
path indefinitely, the old system goes.
Deleted: datasette/tracer.py, the trace_debug setting, the AsgiTracer
response-rewriting middleware and the ?_trace=1 query-string argument.
- datasette/database.py: the four `with trace(...)` wrappers PR 1 deliberately
nested the OTel spans inside are removed and the bodies dedented. That also
retires the `# noqa: SIM117` comments those wrappers required - a leftover
unnecessary noqa trips ruff's RUF100 - and `kwargs["count"] = count` in
execute_write_many, which fed the old tracer only. `git diff -w` on this file
shows nothing but the deleted lines.
- datasette/views/base.py: stream_csv() still read ?_trace=1 to wrap CSV output
in an HTML <textarea> debug page. That whole branch, including the
EscapeHtmlWriter selection and the conditional content-type, is gone. The
EscapeHtmlWriter class itself stays in datasette.utils - it is an importable
public name and removing it would widen the API break.
- .github/workflows/deploy-latest.yml no longer passes --setting trace_debug 1.
Worth stating precisely, because the ticket claimed otherwise: this would not
have broken the deploy. Setting.convert() in cli.py only rewrites a bare name
to settings.<name> for *known* settings, so `--setting trace_debug 1` would
have been silently accepted as a meaningless top-level config key. The flag is
removed because it is dead, not because it errors.
Tests. tests/test_tracer.py is deleted outright (6 items). Four other tests used
?_trace=1 as an assertion instrument rather than testing tracing:
- test_csv_trace tested the trace mechanism itself - deleted.
- test_table_csv_stream_does_not_calculate_facets,
test_table_csv_stream_does_not_calculate_counts and
test_nocount_nofacet_if_shape_is_object test real behaviour, and are rebuilt
against captured spans. All three had silently stopped being able to fail: the
facets test looked for "select content, count(*) as n", which facet suggestion
has not emitted since it moved to a `with limited as (...)` CTE, and none of
the three requested the count or facet work whose suppression they claim to
check. The rebuilt versions ask for it explicitly, match strings the current
SQL contains, and carry a guard assertion so an empty span list cannot
masquerade as a pass. Each was confirmed to fail with the covered code broken.
- test_trace_correctly_escaped is kept, renamed test_query_page_escapes_sql,
with ?_trace=1 dropped. It ran against ds_client, which has no trace_debug, so
it never exercised the tracer - what it actually covered is the query page
echoing user SQL into HTML, the surface of the two reflected-XSS advisories in
issue 1360, and nothing else in the suite covers it. Deleting it would have
quietly dropped that.
tests/test_utils.py's pairs_to_nested_config case used settings.trace_debug to
check that a later key overrides an earlier one; it now uses template_debug
rather than losing the case.
Docs: the datasette.tracer section of internals.rst, the trace_debug section of
settings.rst, the ?_trace=1 entries in json_api.rst and introspection.rst, and
the regenerated cli-reference.rst. changelog.rst gets a breaking-change entry
and keeps all its historical ?_trace=1 entries - two of them had to lose a
:ref: role pointing at a label this commit deletes, or Sphinx warns on every
build.
2368 passed, 39 skipped, 6 xfailed, 15 xpassed, 140 subtests, against 2375 /
141 before. Net -7 tests, fully accounted for: -6 test_tracer.py, -1
test_csv_trace, -1 test_trace_correctly_escaped, +1 test_query_page_escapes_sql.
The lost subtest is the per-setting case trace_debug generated in
test_settings_are_documented.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
* Update docs: explain allow_download setting
This fixes one possible source of confusion seen in #502 and clarifies
when database downloads will be shown and allowed.
