Document how to test a picocli spring-boot application

[remkop]

Add the following dependency to your build.gradle:

dependencies {
    // ...
    testCompile "org.springframework.boot:spring-boot-starter-test:$springBootVersion"
}

A test can look like this:

package picocli.spring.boot.autoconfigure.sample.test;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import picocli.CommandLine;
import picocli.spring.boot.autoconfigure.sample.MyCommand;
import picocli.spring.boot.autoconfigure.sample.MySpringApp;

import static org.junit.Assert.*;
import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.NONE;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = NONE, classes = MySpringApp.class)
public class ExampleTest {

    @Autowired
    CommandLine.IFactory factory;

    @Autowired
    MyCommand myCommand;

    @Test
    public void testParsingCommandLineArgs() {
        CommandLine.ParseResult parseResult = new CommandLine(myCommand, factory)
                .parseArgs("-x", "abc", "sub", "-y", "123");
        assertEquals("abc", myCommand.x);
        assertNull(myCommand.positionals);

        assertTrue(parseResult.hasSubcommand());
        CommandLine.ParseResult subResult = parseResult.subcommand();
        MyCommand.Sub sub = (MyCommand.Sub) subResult.commandSpec().userObject();
        assertEquals("123", sub.y);
        assertNull(sub.positionals);
    }

    @Test
    public void testUsageHelp() {
        String expected = String.format("" +
                "Usage: mycommand [-hV] [-x=<x>] [<positionals>...] [COMMAND]%n" +
                "      [<positionals>...]   positional params%n" +
                "  -h, --help               Show this help message and exit.%n" +
                "  -V, --version            Print version information and exit.%n" +
                "  -x=<x>                   optional option%n" +
                "Commands:%n" +
                "  sub%n");
        String actual = new CommandLine(myCommand, factory).getUsageMessage(CommandLine.Help.Ansi.OFF);
        assertEquals(expected, actual);
    }
}

[dkirrane]

Hi @remkop, I've tried this out but the test never runs? It just always prints usage details. Never gets to first line of test even. Looks like MySpringApp loads up and then exists with usage details.

[dkirrane]

Nevermind I see the issue. I had this in the @SpringBootApplication run method

       if (args.length == 0) {
            new CommandLine(mainCommand, factory).usage(System.out);
            System.exit(2);
        }

[remkop]

@dkirrane Can you show some more detail on the program output? Did you use the example above exactly, including the picocli.spring.boot.autoconfigure.sample.MyCommand and MySpringApp from the picocli-spring-boot-starter tests?

[remkop]

Ah, our messages got crossed. Glad you solved it!

[remkop]

TODO
Add this link to the picocli-spring-boot README:

https://github.com/remkop/picocli/blob/main/picocli-spring-boot-starter/src/test/java/picocli/spring/boot/autoconfigure/example/test/ExampleTest.java