[Fixed Assets] Fix Straight-Line % depreciation to use basis reduced by bonus depreciation

[dcenic]

Fixes AB#640613

Bonus depreciation reduces book value but not the depreciable basis, so the straight-line base must be lowered by the bonus amount each period. Applies the reduction in CalcSLAmount across W1/FR/GB/IT/RU and adds a W1 test.

What & why

Bonus depreciation reduces book value but not the depreciable basis, so the straight-line base must be lowered by the bonus amount each period. Applies the reduction in CalcSLAmount across W1/FR/GB/IT/RU and adds a W1 test.

Linked work

Fixes AB#640613

How I validated this

• I read the full diff and it contains only changes I intended.
• I built the affected app(s) locally with no new analyzer warnings.
• I ran the change in Business Central and confirmed it behaves as expected.
• I added or updated tests for the new behavior, or explained below why none are needed.

What I tested and the outcome (required — be specific: scenarios, commands, screenshots for UI changes)

I made automated tests that make sure that straight-line depreciation method uses the bonus-reduced acquisition cost as the basis for the first and any further depreciation.

Risk & compatibility

[github-actions]

$\textbf{🟡\ Medium\ Severity\ —\ Style} \quad \color{gray}{\texttt{\small Iteration\ 1}}$

StraightLineBonusBaseReduction() is a local procedure of codeunit 5611 'Calculate Normal Depreciation' and is called from CalcSLAmount without the 'this.' prefix.

CodeCop AA0248 requires self-referencing calls inside a codeunit to be prefixed with 'this.' to make the resolution unambiguous. Replace StraightLineBonusBaseReduction() with this.StraightLineBonusBaseReduction().

Suggested change

	Result := (-SLPercent / 100) * (NumberOfDays / DaysInFiscalYear) * (DeprBasis - StraightLineBonusBaseReduction());
	Result := (-SLPercent / 100) * (NumberOfDays / DaysInFiscalYear) * (DeprBasis - this.StraightLineBonusBaseReduction());

Knowledge:

• microsoft/knowledge/style/this-keyword-in-codeunits.md

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[github-actions]

Copilot PR Review

Iteration 3 · Outcome: completed

Knowledge source: https://github.com/microsoft/BCQuality@822cae1b2771ac25f665f73369f69093bd4fd630

Orchestrator pre-filter (13 file(s) excluded)

• layer-disabled (knowledge) : 13 file(s)

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