Opened 17 months ago

Closed 12 months ago

Last modified 12 months ago

#24425 closed defect (fixed)

Fix inherently failing random_expr doctest

Reported by: rws Owned by:
Priority: major Milestone: sage-8.2
Component: symbolics Keywords:
Cc: Merged in:
Authors: Ralf Stephan Reviewers: Marc Mezzarobba
Report Upstream: N/A Work issues:
Branch: a17755c (Commits) Commit:
Dependencies: Stopgaps:

Description (last modified by rws)

The docs for random_expr read:

  This function will often raise an error because it tries to create
  an erroneous expression (such as a division by zero).

It has the following doctest:

        sage: from sage.symbolic.random_tests import *
        sage: set_random_seed(53)
        sage: random_expr(50, nvars=3, coeff_generator=CDF.random_element) # random
        (v1^(0.97134084277 + 0.195868299334*I)/csc(-pi + v1^2 + v3) + sgn(1/
...

Despite having a random seed the test run changes with every new builtin function introduced in sage/functions because the global function list changes. That's why the test was marked random. The problem however is that the test can even raise an error, as the docs state above. The"random" keyword does not catch this, and it would make the test useless anyway.

Tests are meant to test the functionality of the associated code so the test and perhaps random_expr should be rewritten such that it allows a test that does not change with a changed global function list.

Change History (8)

comment:1 Changed 17 months ago by rws

The lazy_import is not even necessary for trigger.

comment:2 Changed 17 months ago by rws

  • Description modified (diff)
  • Summary changed from random_expr changes behaviour when unrelated code is changed to Minimize random_expr's raising exceptions

comment:3 Changed 17 months ago by rws

  • Description modified (diff)
  • Summary changed from Minimize random_expr's raising exceptions to Fix inherently failing random_expr doctest

comment:4 Changed 17 months ago by rws

  • Branch set to u/rws/fix_inherently_failing_random_expr_doctest

comment:5 Changed 17 months ago by rws

  • Authors set to Ralf Stephan
  • Commit set to a17755c56a524033d3075a737f4a08facd012dbb
  • Status changed from new to needs_review

New commits:

a17755c24425: Fix inherently failing random_expr doctest

comment:6 Changed 12 months ago by mmezzarobba

  • Reviewers set to Marc Mezzarobba
  • Status changed from needs_review to positive_review

I don't fully understand the context, but the change looks reasonable and really unlikely to break anything—and this ticket has been languishing for months.

Last edited 12 months ago by mmezzarobba (previous) (diff)

comment:7 Changed 12 months ago by vbraun

  • Branch changed from u/rws/fix_inherently_failing_random_expr_doctest to a17755c56a524033d3075a737f4a08facd012dbb
  • Resolution set to fixed
  • Status changed from positive_review to closed

comment:8 Changed 12 months ago by rws

  • Commit a17755c56a524033d3075a737f4a08facd012dbb deleted

Thanks. Oddly enough, #24212 depends on this.

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