[GRADLE-827] Task cannot call local methods - bug in metaclass Created: 18/Feb/10  Updated: 10/Feb/17  Resolved: 10/Feb/17

Status: Resolved
Project: Gradle
Affects Version/s: 0.9
Fix Version/s: None

Type: Bug
Reporter: Peter Ledbrook Assignee: Unassigned
Resolution: Won't Fix Votes: 0

Attachments: Zip Archive gradle-metaclass-bug.zip    


There seems to be a problem in the metaclass for tasks, or at least task actions within tasks.

It's nice to break down functionality into private methods and call these from the task action, and on the whole, this works. However, if a local method is called from inside an 'each' loop, Gradle complains it can't find the method. See the attached project for a demonstration. Simply run gradle hi.

A workaround in this case is to use a for loop instead of each(), but what it a closure is necessary?

Comment by Hans Dockter [ 08/Jun/10 ]

Let's wait for Groovy to fix this bug.

Comment by Luke Daley [ 02/Aug/13 ]

We should close this.

Comment by Peter Ledbrook [ 02/Aug/13 ]

The example doesn't work in Gradle 1.7 RC2. I updated the various bits of syntax, but HelloTask:

package org.example

import org.gradle.api.DefaultTask
import org.gradle.api.tasks.TaskAction

class HelloTask extends DefaultTask {
    void sayHello() {
        printGreeting("Hello world!")

        def n = [ 1, 2, 3 ]
        for (i in n) {
            printGreeting("[$i] Hi!")

        n.each {
            printGreeting("[$it] Hello world!")

    private void printGreeting(String greeting) {
        println greeting

is complaining at runtime that there is an argument type mismatch. If I explicitly add .toString() to the two GString s, the task works. This seems like a bug since Groovy will normally auto-coerce GString to String. I'll see if I can replicate in a simple Groovy script because I don't see how this can be Gradle (unless @TaskAction is doing something nasty).

Comment by Luke Daley [ 02/Aug/13 ]

Actually, it's probably due to the dynamic subclassing we do at runtime.

It would be helpful to know what plain Groovy would do here.

Comment by Adam Murdoch [ 04/Aug/13 ]

We can't close this until we stop decorating by subclassing.

Comment by Benjamin Muschko [ 15/Nov/16 ]

As announced on the Gradle blog we are planning to completely migrate issues from JIRA to GitHub.

We intend to prioritize issues that are actionable and impactful while working more closely with the community. Many of our JIRA issues are inactionable or irrelevant. We would like to request your help to ensure we can appropriately prioritize JIRA issues you’ve contributed to.

Please confirm that you still advocate for your JIRA issue before December 10th, 2016 by:

  • Checking that your issues contain requisite context, impact, behaviors, and examples as described in our published guidelines.
  • Leave a comment on the JIRA issue or open a new GitHub issue confirming that the above is complete.

We look forward to collaborating with you more closely on GitHub. Thank you for your contribution to Gradle!

Comment by Benjamin Muschko [ 10/Feb/17 ]

Thanks again for reporting this issue. We haven't heard back from you after our inquiry from November 15th. We are closing this issue now. Please create an issue on GitHub if you still feel passionate about getting it resolved.

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