FINERACT-1266: Fix NullPointerException in SavingsHelper.determineInterestPostingPeriods

[airajena]

Description

Fixes NullPointerException that occurs in SavingsHelper.determineInterestPostingPeriods() when date parameters are null.

The NPE occurs when closing a Fixed Deposit account if the maturity date is null (e.g., when depositPeriodFrequencyType is INVALID).

Root Cause

The method determineInterestPostingPeriods() uses DateUtils.isAfter() which throws NPE when either startInterestCalculationLocalDate or interestPostingUpToDate is null.

Fix

Added null check at the start of the method to return an empty list early if either date parameter is null.

Testing

• Fix compiles successfully
• Verified the null check prevents the NPE scenario from the stack trace

Related Issue

Fixes FINERACT-1266

[adamsaghy]

@airajena Please rebase this PR with latest develop branch.

[adamsaghy]

Please explain this new condition and why it is the correct behavior?

[airajena]

The null check prevents a NullPointerException that occurs when either startInterestCalculationLocalDate or interestPostingUpToDate is null.

DateUtils.isAfter() at line 64 throws NPE when comparing null dates, This happens when closing a Fixed Deposit account where depositPeriodFrequencyType is INVALID, causing the maturity date (and subsequently interestPostingUpToDate) to be null

If either date is null, there are no valid interest posting periods to determine

• An empty list semantically means "no posting periods" - which is accurate when dates are undefined
• This allows the calling code (e.g., account closure) to continue gracefully

I've also rebased the PR with the latest develop branch as requested.

[adamsaghy]

In what situations can these values be null?

[airajena]

interestPostingUpToDate can be null when:
depositPeriodFrequencyType is INVALID: In FixedDepositAccount.calculateMaturityDate(), the switch statement handles DAYS, WEEKS, MONTHS, and YEARS, but when depositPeriodFrequencyType is INVALID, it falls through with an empty break, leaving maturityDate as null:

Database has null/invalid deposit_period_frequency_enum: SavingsPeriodFrequencyType.fromInt() returns INVALID when the input is null or an unrecognized value. The column deposit_period_frequency_enum is marked as nullable = true in DepositAccountTermAndPreClosure

Account reinvestment: DepositAccountTermAndPreClosure.copy() explicitly sets maturityDate = null when creating a copy for reinvestment.

startInterestCalculationLocalDate can be null when:
Account in early submission state: accountSubmittedOrActivationDate() could return null if both activationDate and submittedOnDate are null.

[adamsaghy]

Kindly see my questions.