Main parameter doesn't support Converter

[Khazrak]

The converter isn't called and I get an Exception:
Exception in thread "main" com.beust.jcommander.ParameterException: Could not invoke null
Reason: Can not set java.nio.file.Path field mypackage.MyCommand.file to java.lang.String

@Parameter(description = "File", converter = PathConverter.class)
private Path file;

(The PathConverter is from JCommander)

If I add a name to the Parameter (like -f) then the converter works like a charm.

Whole class:
MyCommand.txt

[juewe]

Fix wrks for me:
in com.beust.jcommander.JCommander#convertValue

`              ...
               String value = a; // If there's a non-quoted version, prefer that one
                Object convertedValue = value;

                 // Fix
                // Main parameter doesn't support Converter
                // https://github.com/cbeust/jcommander/issues/380
                convertedValue = convertValue(mainParameter.parameterized, mainParameter.parameterized.getType(), null, value);

                Type genericType = mainParameter.parameterized.getGenericType();
                if (genericType instanceof ParameterizedType) {
               ...

`

[jeremysolarz]

Dear @juewe,

Thanks for the fix for issue #380 but your fix breaks the tests ...

java.lang.AssertionError: Lists differ at element [0]: a != [a] expected [a] but found [[a]]
	at org.testng.Assert.fail(Assert.java:94)
	at org.testng.Assert.failNotEquals(Assert.java:513)
	at org.testng.Assert.assertEqualsImpl(Assert.java:135)
	at org.testng.Assert.assertEquals(Assert.java:568)
	at org.testng.Assert.assertEquals(Assert.java:533)
	at com.beust.jcommander.JCommanderTest.listParameters(JCommanderTest.java:457)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:100)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:646)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:811)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1137)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:129)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:112)
	at org.testng.TestRunner.privateRun(TestRunner.java:749)
	at org.testng.TestRunner.run(TestRunner.java:603)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:368)
	at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:363)
	at org.testng.SuiteRunner.privateRun(SuiteRunner.java:321)
	at org.testng.SuiteRunner.run(SuiteRunner.java:270)
	at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
	at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
	at org.testng.TestNG.runSuitesSequentially(TestNG.java:1284)
	at org.testng.TestNG.runSuitesLocally(TestNG.java:1209)
	at org.testng.TestNG.runSuites(TestNG.java:1124)
	at org.testng.TestNG.run(TestNG.java:1096)
	at org.gradle.api.internal.tasks.testing.testng.TestNGTestClassProcessor.runTests(TestNGTestClassProcessor.java:129)
	at org.gradle.api.internal.tasks.testing.testng.TestNGTestClassProcessor.stop(TestNGTestClassProcessor.java:88)
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:61)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32)
	at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93)
	at com.sun.proxy.$Proxy3.stop(Unknown Source)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.stop(TestWorker.java:120)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:377)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
	at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

Best,

JS

[juewe]

Hi Jeremy,
next try:
Added a check in JCommander.java testing if Converter is specified and is not a NoConverter.
Added a Argument-Class and enhancing JCommanderTest with Testcase for Mainparams with a Converter.

Created a patch (simply delete the ".txt" extension form file.

Hope that helps...

FIX360v2.patch.txt

[acostalima]

@juewe submit a PR

[jzwolak]

This issue was fixed 9 months ago and there hasn't been a release since then... so I ran into the bug, too. @cbeust, will you be making a release?

[cbeust]

1.74 was released about a month ago:

https://bintray.com/cbeust/maven/jcommander/1.74

[la-costa]

It looks like the problem was fixed in version 1.74.

[antonio-rodriges]

Thanks for adding converter capability to parse the main param:

jcommander/src/main/java/com/beust/jcommander/JCommander.java

Lines 766 to 771 in 0525445

	// Fix
	// Main parameter doesn't support Converter
	// https://github.com/cbeust/jcommander/issues/380
	if (mainParameter.annotation.converter() != null && mainParameter.annotation.converter() != NoConverter.class){
	convertedValue = convertValue(mainParameter.parameterized, mainParameter.parameterized.getType(), null, value);
	}

However, the code does not work if we provide IStringConverterFactory. A workaround is to specify a dummy converter class for the main parameter that cannot be instantiated.

I noticed the solution above Added a check in JCommander.java testing if Converter is specified and is not a NoConverter.

But the condition

jcommander/src/main/java/com/beust/jcommander/JCommander.java

Line 769 in 0525445

if (mainParameter.annotation.converter() != null && mainParameter.annotation.converter() != NoConverter.class){

prevents using the IStringConverterFactory. It would be good to call convertValue anyway. All in all, if there is no appropriate converter, it would just return the same string

jcommander/src/main/java/com/beust/jcommander/JCommander.java

Line 1373 in 0525445

converter = new StringConverter();

However, to avoid breaking tests without the condition, should the if clause be extended to account for IStringConverterFactory?