ascheman commented on issue #11701:
URL: https://github.com/apache/maven/issues/11701#issuecomment-3897961755
## AC8 and AC9: Legacy Directory Handling with `<sources>`
This comment clarifies the acceptance criteria for handling legacy
directories (`<sourceDirectory>`, `<testSourceDirectory>`) when `<sources>` is
configured (based on respective discussions in the course of #11702).
### AC8: Modular Projects
For **modular projects** (projects with `<module>` attribute in `<source>`
elements), **all legacy directories are rejected**:
1. **Explicit configuration**: If legacy directory differs from Super POM
default → **ERROR**
2. **Physical presence**: If default directory (`src/main/java`) exists on
filesystem → **ERROR**
**Rationale**: Modular projects use paths like `src/<module>/main/java`.
Content in legacy directories cannot be dispatched between modules and would be
silently ignored.
### AC9: Non-Modular Projects
For **non-modular projects** using `<sources>`:
1. **When `<sources>` has Java for a scope**: Legacy directories are
rejected if they differ from the default
2. **When `<sources>` has no Java for a scope**: Legacy directories are used
as **implicit fallback** only if they match the default
| `<sources>` has Java? | Legacy differs from default? | Result |
|-----------------------|------------------------------|--------|
| Yes | Yes | **ERROR** |
| Yes | No | OK (ignored, use `<sources>`) |
| No | Yes | **ERROR** |
| No | No | OK (implicit fallback) |
**Rationale**: This allows incremental adoption of `<sources>`:
- Customize only specific source types (e.g., resources) while keeping
default Java directories
- Explicit legacy overrides always trigger errors (detectable configuration
mixing)
### Limitation
Maven works with the effective model after inheritance resolution. It cannot
distinguish whether a value matching the default was inherited (from Super POM
or any parent) or explicitly configured. For modular projects, the physical
presence check provides an additional safeguard.
### Example: AC9 Implicit Fallback
```xml
<build>
<sources>
<!-- Only customize resources -->
<source>
<lang>resources</lang>
<scope>main</scope>
<directory>src/main/custom-resources</directory>
</source>
</sources>
<!-- src/main/java is used implicitly (AC9 fallback) -->
</build>
```
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
