HF-160: ADDRESS drops the sheet separator when sheetName is empty

[marcin-kordas-hoc]

Fixes HF-160 (GH #1641): =ADDRESS(2,3,1,FALSE(),) returned !R2C3 — the sheet separator was emitted for an empty-string sheet name. Excel returns R2C3.

What changed

One condition in AddressPlugin: an empty string no longer produces a sheet prefix, for both A1 and R1C1 styles. Non-empty sheet names keep producing Sheet1!R2C3 exactly as before.

Verification

Paired tests: hyperformula-tests@spike/hf160-address-sheetname (37 assertions: trailing-comma / explicit "" / omitted forms in both styles, non-empty names pinned unchanged). Full unit/interpreter 390 suites / 3531 tests green, tsc --noEmit clean, eslint --quiet clean.

🤖 Generated with Claude Code

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Note

Low Risk
Single-condition change in ADDRESS string formatting; no auth, data, or broad API impact.

Overview
Fixes HF-160: ADDRESS no longer emits a stray ! when the optional sheet name is an empty string (e.g. trailing comma or explicit ""), so R1C1 results match Excel (R2C3 instead of !R2C3).

The only code change is in AddressPlugin: the sheet prefix is built only when sheetName is defined, non-null, and non-empty. Non-empty names still produce Sheet1!… as before.

^{Reviewed by Cursor Bugbot for commit deb5b76. Bugbot is set up for automated code reviews on this repo. Configure here.}

[qunabu]

Task linked: HF-160 Fix ADDRESS returning '!R2C3' when sheetName is empty

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Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	hyperformula-docs	62cb944	Commit Preview URL Branch Preview URL	Aug 20 2026, 09:04 AM

[github-actions]

Performance comparison of head (62cb944) vs base (61ead73)

                                     testName |    base |    head | change
--------------------------------------------------------------------------
                                      Sheet A |  500.56 |  497.53 | -0.61%
                                      Sheet B |  162.33 |  163.48 | +0.71%
                                      Sheet T |  145.27 |  141.92 | -2.31%
                                Column ranges |  479.58 |  476.99 | -0.54%
                                Sorted lookup | 14657.9 | 14181.8 | -3.25%
Sheet A:  change value, add/remove row/column |   17.36 |   16.34 | -5.88%
 Sheet B: change value, add/remove row/column |  134.42 |     145 | +7.87%
                   Column ranges - add column |  152.65 |  156.51 | +2.53%
                Column ranges - without batch |  460.02 |  474.98 | +3.25%
                        Column ranges - batch |  120.85 |  121.08 | +0.19%

[marcin-kordas-hoc]

Paired tests PR: handsontable/hyperformula-tests#40 — merge it BEFORE this one.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.31%. Comparing base (61ead73) to head (62cb944).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #1739   +/-   ##
========================================
  Coverage    97.31%   97.31%           
========================================
  Files          195      195           
  Lines        15719    15719           
  Branches      3455     3384   -71     
========================================
  Hits         15297    15297           
- Misses         414      422    +8     
+ Partials         8        0    -8     

Files with missing lines	Coverage Δ
src/interpreter/plugin/AddressPlugin.ts	100.00% <100.00%> (ø)

... and 5 files with indirect coverage changes

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