feat: update default number formats to trim insignificant trailing zeros

[vasilev-alex]

No description provided.

[claude]

Claude finished @vasilev-alex's task in 2m 9s —— View job

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Code Review: Update default number formats to trim trailing zeros

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Summary

This PR adds the d3-format ~ (trim) modifier to all default and named numeric format specifiers, so that insignificant trailing zeros are stripped. For example, 1,234.00 → 1,234, $42.50 → $42.5, 0.00% → 0%.

The change is clean and consistent — all format definitions in both cubejs-client-core and cubejs-schema-compiler are updated in lockstep, tests and snapshots are properly adjusted, and custom-numeric user-provided format strings are correctly left untouched.

What looks good

• Consistent application: The ~ modifier is applied uniformly across all format families (number, currency, percent, abbr, decimal, accounting, id) in both packages.
• Test coverage is thorough: Tests cover the key behavioral changes (e.g., $0.00 → $0, 1,234.00 → 1,234, 0.00% → 0%) and snapshots are updated.
• User-specified formats preserved: The custom-numeric code path correctly passes user format strings through as-is (line 153 of format.ts), so only defaults change.
• Dependency compatibility: d3-format ^3.1.0 fully supports the ~ modifier (introduced in v2.0.0).

Items to address

1. Breaking change for currency display (inline comment posted) — Financial convention strongly favors fixed two-decimal display ($42.50, not $42.5). Consider whether DEFAULT_CURRENCY_FORMAT and the currency_* named formats should keep fixed precision, or document this as an intentional behavior change. This is the main point worth discussing.

2. Redundant ~ on precision-0 formats (inline comment posted) — Specifiers like ,.0~f, .0~%, .0~s are functionally identical to ,.0f, .0%, .0s since there are no fractional digits to trim. Not a bug, but removing ~ from the _0 variants would be slightly cleaner and avoid implying trimming can happen when it can't. Alternatively, keeping it for consistency is also reasonable — just a nit.

3. PR description — This is a user-facing behavioral change. A brief description explaining the motivation (e.g., "integer values shouldn't display .00 suffix") and acknowledging it as a breaking change would help reviewers and future changelog readers.

No issues found

• Security: No security concerns — this is a pure formatting change with no user input handling changes.
• Performance: No performance impact — ~ is handled natively by d3-format.
• Architecture: The change is well-scoped to the two relevant packages with no unintended side effects.

Overall this is a clean, well-tested change. The main discussion point is whether currency formats should also trim trailing zeros given financial display conventions.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 57.99%. Comparing base (f395432) to head (7e73add).
⚠️ Report is 6 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #10782   +/-   ##
=======================================
  Coverage   57.99%   57.99%           
=======================================
  Files         215      215           
  Lines       16775    16776    +1     
  Branches     3388     3388           
=======================================
+ Hits         9728     9730    +2     
+ Misses       6554     6553    -1     
  Partials      493      493           

Flag	Coverage Δ
cube-backend	57.99% <ø> (+<0.01%)	⬆️

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