mkdirs return value is ignored

[elharo]

Affected version

HEAD

Bug description

There is a lot of code scattered throughout the project where we do things like

    metainfDir.mkdirs();

without checking if the operation succeeded. Depending on context this can result in a harder to diagnose exception further down the line, or a war file that is simply missing things it should have. Either way we should check the results of these operations and throw the available mojo exception earlier.

[HarshMehta112]

@elharo I got your point. We need to add proper checks around all mkdir()/mkdirs() calls and throw a MojoExecutionException when directory creation fails, ensuring early and clear error reporting instead of harder-to-diagnose issues later or incomplete WAR files. The changes remain consistent across the plugin and do not affect existing functionality.

Replace calls like metainfDir.mkdirs(); with explicit checks:

if (!metainfDir.exists() && !metainfDir.mkdirs()) {
    throw new MojoExecutionException(
        "Failed to create directory: " + metainfDir.getAbsolutePath());
}

Let me know if I can proceed with a PR. Thanks!