[AVRO-3582] Avro Maven plug in should fail if imports do not resolve to actual file/directory

• Type: Improvement
• Status: Patch Available
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.10.2, 1.12.0
• Component/s: java, tools

Language

Java

• Assignee: Unassigned
• Reporter: Filip
• Created: 19/Jul/22 12:36
• Updated: 19/Jul/22 12:47

Description

org.apache.avro.mojo.AbstractAvroMojo#getIncludedFiles contains the following code:

251 // exclude imports directory since it has already been compiled.
252 if (imports != null) {
253   String importExclude = null;
254
255   for (String importFile : this.imports) {
256     File file = new File(importFile);
257
258     if (file.isDirectory()) {
259       importExclude = file.getName() + "/**";
260     } else if (file.isFile()) {
261       importExclude = "**/" + file.getName();
262     }
263 
264     fs.addExclude(importExclude);
265   }
266 } 

which is supposed to explicitly exclude any directories that have been added through an <import>...</import> configuration property.

Unfortunately, when the configuration property does not resolve to an actual file or directory, e.g.:

<imports>
  <!-- note the erroneous extra / at the beginning -->
  <import>/${basedir}/src/main/resources/schemas/</import>
</imports>

Then both checks at line no. 258 and 260 evaluate to false, meaning that in line no. 264 the code:

fs.addExclude(null);

is executed.

This leads to the behaviour that the following condition in the org.apache.maven.shared.model.fileset.util.FileSetManager#scan code:

656 if ( excludesArray.length > 0 )
657 {
658     scanner.setExcludes( excludesArray );
659 } 

evaluates to true, causing an exception to occur in  org.apache.maven.shared.utils.io.DirectoryScanner#setExcludes

357 pattern = excludes[i].trim().replace( '/', File.separatorChar ).replace( '\\', File.separatorChar );

with the Maven error:

[ERROR] Failed to execute goal org.apache.avro:avro-maven-plugin:1.11.0:schema (default) on project app: Execution default of goal org.apache.avro:avro-maven-plugin:1.11.0:schema failed: Cannot invoke "String.trim()" because "excludes[i]" is null -> [Help 1]
 

which is highly unintuitive and has cost me almost a day of debugging now. The error is ultimately caused by the user (me!), but IMO org.apache.avro.mojo.AbstractAvroMojo#getIncludedFiles should simply throw an exception if the file path cannot be resolve to an actual directory or file.

IMO, fail-fast behaviour when given incorrect configuration is a must for robust software, instead of getting a cryptic message from the underlying platform code.

Proposed change attached. An alternative solution via file.exists() would also work. Strictly speaking, throwing a FileNotFoundException would be more semantically correct, but I did not wish to add more checked exceptions. The current one is already rethrown by all calling methods.

If the change seems OK, I can include a test case as well (should be very simple).