jdl: error passing 0 value in field annotations.

[dharmeshmp]

Issue Description

When adding new fields with @defaultValue in a JHipster entity, the generated Liquibase changelog does not correctly set the default values in the database. Specifically, the changelog generates the following incorrect XML:

<column name="games_played" type="integer" defaultValueNumeric="true">
    <constraints nullable="true" />
</column>

This leads to the following problems:

1. defaultValueNumeric="true" is invalid and does not set the intended default value (e.g., 0).
2. The column constraints incorrectly allow NULL values, even though the @defaultValue annotation implies it should be NOT NULL.

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Steps to Reproduce

1. Create a JHipster entity with fields that have @defaultValue annotations:

   entity Player {
       displayName String required
       coins Integer required
       @defaultValue(0) gamesPlayed Integer
       @defaultValue(0) gamesWon Integer
   }

2. Generate the Liquibase changelog by running:

   jhipster jdl jhipster-jdl.jdl 

3. Check the generated Liquibase changelog file.

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Expected Behavior

The generated changelog should correctly define default values and nullable constraints. For example:

<column name="games_played" type="integer" defaultValueNumeric="0">
    <constraints nullable="false" />
</column>

---

Observed Behavior

The generated changelog incorrectly defines the columns as follows:

<column name="games_played" type="integer" defaultValueNumeric="true">
    <constraints nullable="true" />
</column>

---

Environment

• JHipster Version: 8.8.0
• JDK Version: 17.0.12
• Database: MySQL
• Operating System: macOS

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Additional Context

This issue can lead to runtime errors or misaligned database schemas, especially when default values and non-null constraints are crucial for business logic.

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Proposed Solution

Update the generator to:

1. Ensure defaultValueNumeric is set to the numeric value provided in the @defaultValue annotation.
2. Automatically set nullable="false" if a @defaultValue is defined.

[mshima]

The bug is in JDL parsing.
@defaultValue(1) works as expected, @defaultValue(0) fails.

You can use @defaultValue("0") as workaround.

[mshima]

I not sure if nullable behavior is expected.
@OmarHawk can you help here?

[OmarHawk]

I not sure if nullable behavior is expected. @OmarHawk can you help here?

No, at the moment it is not expected that you don't pass a value. So, there should always be a parameter here.

[mshima]

Fixed by #28753