Fix extract_strata() stripping parentheses from strata level labels

[ddsjoberg]

Summary

Fixes the greedy regex in extract_strata() that destroyed parentheses in factor level values. For example, a strata level "Drug (B)" was truncated to "B".

Closes ddsjoberg/gtsummary#2388

Changes

The two gsub(".*\\(", "", gsub("\\)", "", ...)) calls were intended to strip strata() wrappers from term labels and strata strings, but they also removed all parentheses from level values. Replaced with targeted patterns:

• Term labels: sub("^strata\\(\\s*([^,)]+).*\\)$", "\\1", x_terms) — only matches the strata(...) wrapper
• Strata strings: gsub("strata\\(([^)]+)\\)", "\\1", i) — only replaces strata(varname) with varname

Testing

Added a test case with parentheses in level labels ("Male (M)", "Female (F)"). Verified no regressions with normal levels, = in levels, unstratified models, multiple stratification variables, and quantile mode.

[github-actions]

Unit Tests Summary

  1 files  193 suites   1m 23s ⏱️
191 tests 153 ✅ 38 💤 0 ❌
705 runs  638 ✅ 67 💤 0 ❌

Results for commit b8b121b.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Performance Difference

Additional test case details

Test Suite	$Status$	Time on main	$±Time$	Test Case
ard_categorical_ci.survey.design	💚	$3.04$	$-1.03$	ard_categorical_ci_data_
ard_summary.survey.design	💚	$24.64$	$-1.66$	unstratified_ard_summary.survey.design_works
ard_survival_survfit	👶		$+0.01$	ard_survival_survfit_preserves_parentheses_in_strata_level_labels
ard_survival_survfit	👶		$+0.00$	extract_strata_returns_safely_and_warns_on_0_row_datasets

Results for commit bd51179

♻️ This comment has been updated with latest results.

[github-actions]

Code Coverage Summary

Filename                                Stmts    Miss  Cover    Missing
------------------------------------  -------  ------  -------  -------------------------------------------
R/add_total_n.survey.design.R              10       0  100.00%
R/ard_aod_wald_test.R                      77       2  97.40%   93, 96
R/ard_attributes.survey.design.R            2       0  100.00%
R/ard_car_anova.R                          45       2  95.56%   62, 65
R/ard_car_vif.R                            68       1  98.53%   93
R/ard_categorical_ci.R                    323       1  99.69%   100
R/ard_categorical_ci.survey.design.R      124       1  99.19%   180
R/ard_continuous_ci.R                      28       1  96.43%   38
R/ard_continuous_ci.survey.design.R       138       0  100.00%
R/ard_continuous.survey.design.R          284      20  92.96%   61-66, 100, 191, 200, 351, 382-383, 434-442
R/ard_effectsize_cohens_d.R               103       2  98.06%   69, 122
R/ard_effectsize_hedges_g.R                91       2  97.80%   68, 120
R/ard_emmeans_contrast.R                   99       0  100.00%
R/ard_emmeans_emmeans.R                    97       0  100.00%
R/ard_incidence_rate.R                    104       0  100.00%
R/ard_missing.survey.design.R              89       7  92.13%   45-50, 63
R/ard_regression_basic.R                   31       1  96.77%   61
R/ard_regression.R                         87       0  100.00%
R/ard_smd_smd.R                            69       5  92.75%   57, 83-86
R/ard_stats_anova.R                        95       0  100.00%
R/ard_stats_aov.R                          46       0  100.00%
R/ard_stats_chisq_test.R                   40       1  97.50%   39
R/ard_stats_fisher_test.R                  43       1  97.67%   42
R/ard_stats_kruskal_test.R                 36       1  97.22%   38
R/ard_stats_mantelhaen_test.R              67       1  98.51%   45
R/ard_stats_mcnemar_test.R                 80       2  97.50%   63, 106
R/ard_stats_mood_test.R                    49       1  97.96%   45
R/ard_stats_oneway_test.R                  39       0  100.00%
R/ard_stats_poisson_test.R                 76       1  98.68%   59
R/ard_stats_prop_test.R                    85       1  98.82%   43
R/ard_stats_t_test_onesample.R             41       0  100.00%
R/ard_stats_t_test.R                      112       2  98.21%   65, 111
R/ard_stats_wilcox_test_onesample.R        42       0  100.00%
R/ard_stats_wilcox_test.R                  99       2  97.98%   65, 117
R/ard_survey_svychisq.R                    38       1  97.37%   44
R/ard_survey_svyranktest.R                 54       1  98.15%   44
R/ard_survey_svyttest.R                    53       1  98.11%   42
R/ard_survival_survdiff.R                  89       0  100.00%
R/ard_survival_survfit_diff.R              76       0  100.00%
R/ard_survival_survfit.R                  243       5  97.94%   234-238
R/ard_tabulate_abnormal.R                  76       0  100.00%
R/ard_tabulate_max.R                       51       7  86.27%   54-59, 74
R/ard_tabulate_value.survey.design.R       80       9  88.75%   40-45, 62, 167, 172
R/ard_tabulate.survey.design.R            407      15  96.31%   70-75, 90, 243-246, 290, 335, 535, 549
R/construction_helpers.R                  106      10  90.57%   160-175, 189, 248
R/deprecated.R                             34      34  0.00%    28-86
R/proportion_ci.R                         203       1  99.51%   463
TOTAL                                    4329     142  96.72%

Diff against main

Filename                    Stmts    Miss  Cover
------------------------  -------  ------  -------
R/ard_survival_survfit.R       +7       0  +0.06%
TOTAL                          +7       0  +0.01%

Results for commit: b8b121b

Minimum allowed coverage is 80%

♻️ This comment has been updated with latest results

[ddsjoberg]

@Melkiades can you review this PR?

[Melkiades]

Looks very good to me! The new regex works perfectly. Thanks @ddsjoberg !!

[ddsjoberg]

Thank you for the review @Melkiades !!