未扩展的GMavenPlus Groovy project.basedir单元测试

Question

我目前正试图用GMavenPlus编写一个Maven插件(谢谢@Keegan!)和Groovy 2.4.3。简单地说，这个插件解析了一个SQL SQL目录，并从那些解析的SQL中生成输出。

当构建、导入并在一个完整的消费项目中运行时，本身工作得很好。霍拉！

问题在于单元测试。当尝试对这个Mojo进行单元测试时，像${project.basedir}这样的Maven POM没有被扩展，因此这个mojo出现了一个错误，比如“文件未找到！${project.basedir}/src/ test /resources/ddl”。从该错误消息中可以看到，${project.basedir}是作为文字传递的，而不是被展开的。

我目前正在使用Maven插件测试Harness (使用固定的依赖项，请参阅这个博客)、JUnit 4.12和AssertJ 3.0.0作为测试堆栈。

有什么想法或具体的技巧可以让project.basedir这样的东西在单元测试中扩展吗？

提前感谢！

有问题的单元测试：

import edge.SqlToScalaMojo
import org.junit.Before
import org.junit.Test

/**
 * Created by medge on 6/15/15.
 */
class SqlToScalaMojoTest extends BaseMojoTest<SqlToScalaMojo> {

    SqlToScalaMojo mojo

    @Before
    void setup() {
        mojo = getMojo("parse-ddls")
    }

    @Test
    void testMojoExecution() throws Exception {
        assertThat mojo isNotNull()

        mojo.execute()
    }
}

BaseMojoTest.groovy (实际上只是一个方便的基类)：

import org.apache.maven.plugin.AbstractMojo
import org.apache.maven.plugin.testing.MojoRule
import org.junit.Rule

/**
 * Base Test class for Mojo tests. Extends {@link org.assertj.core.api.Assertions}
 *
 * If a type is given to this class then the result of #getMojo() does not have to be cast, reducing the amount of code
 * to be written in the unit tests themselves.
 *
 * Created by medge on 6/5/15.
 */
abstract class BaseMojoTest<T extends AbstractMojo> extends org.assertj.core.api.Assertions {

    /**
     * MojoRule used to lookup Mojos
     */
    @Rule public MojoRule rule = new MojoRule()

    /**
     * Get a configured mojo using the default pom file. Calls #getMojo(goal, getPom()) implicitly
     *
     * @param goal Goal to look up
     * @return T configured Mojo
     */
    T getMojo(String goal) {
        getMojo(goal, getPom())
    }

    /**
     * Get a configured mojo using the specified pom file
     *
     * @param goal Goal to look up
     * @param pom POM file to use when configuring Mojo
     * @return T configured Mojo
     */
    T getMojo(String goal, File pom) {
        T mojo = (T) rule.lookupMojo(goal, pom)

        mojo
    }

    /**
     * Default POM file if no custom path is given
     */
    String defaultPomPath = "src/test/resources/plugin-config.xml"

    /**
     * Return a File reference containing the default POM file
     *
     * @return File
     */
    File getPom() {
        getPom(defaultPomPath)
    }

    /**
     * Return a File reference containing the POM file found at the specified path. Implicitly asserts that the POM
     * exists using <code>assertFile</code>
     *
     * @param path Path to user-defined POM (overrides the default if provided)
     * @return File containing the specified POM.
     */
    File getPom(String path) {
        File _pom = getTestFile(path)

        // Implicitly assert POM exists
        assertFile(_pom)

        // Then return the POM file
        _pom
    }

    /**
     * Convenience method to assert that a file is valid
     *
     * @param file File to validate
     */
    static void assertFile(File file) {
        assertThat file isNotNull()
        assertThat file exists()
    }

    /**
     * Get the current project's base directory. From {@link org.codehaus.plexus.PlexusTestCase}
     *
     * @return Base directory path
     */
    static String getBaseDir() {
        final String path = System.getProperty( "basedir" );

        path ?: new File( "" ).getAbsolutePath();
    }

    /**
     * Return a test file from the src/test/resources directory. Assumes the base directory is src/test/resources so the
     * src/test/resources prefix can be omitted from the path if desired
     *
     * @param path File path
     * @return File
     */
    static File getTestFile(String path) {
        File testFile

        if(path.indexOf("src/test/resources/") > -1)
            testFile = getTestFile(getBaseDir(), path)
        else
            testFile = getTestFile(getBaseDir(), "src/test/resources/${path}")

        testFile
    }

    /**
     * Retrieve a test file from the given baseDir/path
     *
     * @param baseDir String base directory to look in
     * @param path String path to the file desired
     * @return File
     */
    static File getTestFile(String baseDir, String path) {
        new File(baseDir, path)
    }
}

Mojo本身的主POM文件：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>edge</groupId>
    <artifactId>parser-mojo</artifactId>
    <version>0.0.3-SNAPSHOT</version>
    <packaging>maven-plugin</packaging>

    <properties>
        <groovy.version>2.4.3</groovy.version>
        <maven.version>3.3.3</maven.version>
        <junit.version>4.12</junit.version>
        <assertj.version>3.0.0</assertj.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.codehaus.groovy</groupId>
            <artifactId>groovy-all</artifactId>
            <version>${groovy.version}</version>
        </dependency>

        <!-- Test dependencies -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
        </dependency>
        <dependency>
            <groupId>org.assertj</groupId>
            <artifactId>assertj-core</artifactId>
            <version>${assertj.version}</version>
            <scope>test</scope>
        </dependency>


        <!-- Dependencies for Maven Mojos -->
        <dependency>
            <groupId>org.codehaus.plexus</groupId>
            <artifactId>plexus-utils</artifactId>
            <version>3.0.22</version>
        </dependency>
        <dependency>
            <groupId>org.apache.maven</groupId>
            <artifactId>maven-core</artifactId>
            <version>${maven.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.maven</groupId>
            <artifactId>maven-artifact</artifactId>
            <version>${maven.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.maven</groupId>
            <artifactId>maven-compat</artifactId>
            <version>${maven.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.maven</groupId>
            <artifactId>maven-plugin-api</artifactId>
            <version>${maven.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.maven.plugin-tools</groupId>
            <artifactId>maven-plugin-annotations</artifactId>
            <version>3.4</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.maven.plugin-testing</groupId>
            <artifactId>maven-plugin-testing-harness</artifactId>
            <version>3.3.0</version>
            <scope>test</scope>
            <type>jar</type>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.codehaus.gmavenplus</groupId>
                <artifactId>gmavenplus-plugin</artifactId>
                <version>1.5</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>addSources</goal>
                            <goal>addTestSources</goal>
                            <goal>generateStubs</goal>
                            <goal>compile</goal>
                            <goal>testGenerateStubs</goal>
                            <goal>testCompile</goal>
                            <goal>removeStubs</goal>
                            <goal>removeTestStubs</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-plugin-plugin</artifactId>
                <version>3.4</version>
                <configuration>
                    <!-- see http://jira.codehaus.org/browse/MNG-5346 -->
                    <skipErrorNoDescriptorsFound>true</skipErrorNoDescriptorsFound>
                </configuration>
                <executions>
                    <execution>
                        <id>generate-descriptor</id>
                        <goals>
                            <goal>descriptor</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>help-goal</id>
                        <goals>
                            <goal>helpmojo</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

单元测试期间使用的测试POM：

<project>
    <build>
        <plugins>
            <plugin>
                <groupId>edge</groupId>
                <artifactId>parser-mojo</artifactId>
                <version>0.0.3-SNAPSHOT</version>
                <configuration>
                    <template>${project.basedir}/src/test/resources/sample.template</template>
                    <inputDir>${project.basedir}/src/test/resources/ddl</inputDir>
                    <outputDir>${project.basedir}/src/test/resources/generated/</outputDir>
                </configuration>
                <executions>
                    <execution>
                        <phase>generate-resources</phase>
                        <goals>
                            <goal>parse-ddls</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

谢谢!

Answer 1

找到了我自己问题的答案。张贴在这里，以防其他人正在寻找同样的问题。

首先，在@Parameter注释方面，我遇到了与Mojo本身有关的另一个问题。以下内容如下：

@Parameter(defaultValue = "${project.basedir}/src/main/resources")
String inputDir

将生成一个错误，因为Groovy编译器将在Maven之前获取字符串"${project.basedir}/src/main/resources"。然后，它将执行其计算，并将其转换为GString。这会生成一个错误，因为注释需要一个java.lang.String，但它将得到java.lang.Object

正如@Keegan在另一个问题中指出的，解决方案是使用单引号而不是双引号：

@Parameter(defaultValue = '${project.basedir}/src/main/resources')
String inputDir

Groovy编译器不会计算字符串，Maven将从中提取

接下来，在单元测试期间，没有读取有关defaultValue的原始问题。罪魁祸首是BaseMojoTest.groovy中的这种方法：

T getMojo(String goal, File pom) {
    T mojo = (T) rule.lookupMojo(goal, pom)

    mojo
}

具体而言，本部分：

rule.lookupMojo(goal, pom)

lookupMojo在MojoRule 上不计算参数注释的默认值。它希望测试POM文件中存在所有可能的参数。快速浏览了一下MojoRule的源代码，我找到了一种修复它的方法：

/**
 * Get a configured mojo using the specified pom file
 *
 * @param goal Goal to look up
 * @param pom POM file to use when configuring Mojo
 * @return T configured Mojo
 */
T getMojo(String goal, File pom) {
    T mojo = (T) rule.lookupConfiguredMojo(getMavenProject(pom), goal)

    mojo
}

/**
 * Method to handle creating a MavenProject instance to create configured Mojos from
 * @param pom File to POM file containing Mojo config
 * @return MavenProject
 */
MavenProject getMavenProject(File pom) {
    // create the MavenProject from the pom.xml file
    MavenExecutionRequest request = new DefaultMavenExecutionRequest()
    ProjectBuildingRequest configuration = request.getProjectBuildingRequest()
            .setRepositorySession(new DefaultRepositorySystemSession())
    MavenProject project = rule.lookup(ProjectBuilder.class).build(pom, configuration).getProject()

    project.basedir = new File(getBaseDir())

    // Implicit assert
    assertThat project isNotNull()

    // And return
    project
}

getMavenProject()方法与MojoRule#readMavenProject()中的代码略有不同，修改后的代码引用了MojoRule和我对getBaseDir()的定义。由该方法生成的Mojos现在正确地评估@Parameter的defaultValue！我确实觉得getMavenProject()可能会变得更有效率(而不是每次创建一个MavenProject )，但是现在已经足够了。

还有一件事

您可能已经注意到getMavenProject()方法中的这一行：

project.basedir = new File(getBaseDir())

这个非常恼人的小黑客是必要的，因为在创建MavenProject对象时：

MavenProject project = rule.lookup(ProjectBuilder.class).build(pom, configuration).getProject()

${project.basedir}实际上成为的基础，这是单元测试中使用的测试POM文件。如果像我一样，在src/ test /resources中有一个测试POM，那么basedir将成为类似于/Users/medge/.../src/test/resources.的东西。因此，当展开${project.basedir}的@参数注释时，例如：

@Parameter(defaultValue='${project.basedir}/src/main/resources')
String inputDir

当从单元测试运行时，inputDir将解析为/Users/medge/.../src/test/resources/src/main/resources。

微妙的事情会把你绊倒..。

希望这对其他人有帮助！

Answer 2

我有一个类似的问题，但我插入路径从配置和发现不同的解决方案。

我将测试项目pom更改为：

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example.maven.plugin.MyPlugin</groupId>
    <artifactId>testProject</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>Test MyPlugin</name>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <artifactId>myPlugin-maven-plugin</artifactId>
                <configuration>
                    <testDirectory>${basedir}\src\test\resources\testDir</testDirectory>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

不同之处在于testDirectory。而

<testDirectory>${project.basedir}\src\test\resources\testDir</testDirectory>

计算结果为相同的字符串，

<testDirectory>${basedir}\src\test\resources\testDir</testDirectory>

计算结果为文件系统C:\Development\projects\..\src\test\resources\testDir上的具体路径。