[GROOVY-9517] CompileStatic typeCasting runtime error from Class Array to Class List

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.19, 3.0.3, 2.5.11
• Fix Version/s: 4.0.0-alpha-1, 3.0.4, 2.5.12
• Component/s: Static compilation
• Labels: CompileStatic
• Environment: Java: openjdk version "1.8.0_242" ; OS: OS X Catalina 10.15.3 ; Groovy: 2.4.19
• Flags: Important
• Assignee: Eric Milles
• Reporter: David Estes
• Created: 20/Apr/20 15:09
• Updated: 22/May/20 04:02
• Resolved: 23/Apr/20 10:54

Description

After upgrading asset-pipeline-core from groovy 2.0.7 to 2.4.15 then 2.4.19 . A bug was identified with @CompileStatic not properly handling runtime type casting when sorting an Array instead of a List

 

Example

 

Create File TestFile.groovy

import groovy.transform.CompileStaticpublic class TestFile {	
    static void main(String[] args) {
        File file = new File('.')
        TestFile testFile = new TestFile()
        testFile.listSortedFiles(file)
    }

    @CompileStatic
    void listSortedFiles(File directory) {
        File[] files = directory.listFiles()
        files = files?.sort { File a, File b -> a.name.compareTo b.name } as File[]
        for(File file in files) {
        }
    }
	
		
}

Then simply run:

groovy TestFile.groovy

 

Exception:

 

Caught: java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.io.File;
java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.io.File;
	at TestFile.listSortedFiles(TestFile.groovy:15)
	at TestFile$listSortedFiles.call(Unknown Source)
	at TestFile.main(TestFile.groovy:8)