Scala Starter Parent Project

Scla Parent Starter Project

• Create Scala SDLC.
• Simplify Scala project bootstrapping.
• Releasing strategy

pom.xml

This is our initial pom file version include the project pom details

<?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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.gability.scala</groupId>
    <artifactId>scala-starter-parent</artifactId>
    <version>1.14-SNAPSHOT</version>
    <packaging>pom</packaging>
</project>

Adding Dependencies for scala testing

In this part we add scala and scala-test libraries in the dependancy section in pom.xml

<?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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>   
    <groupId>com.gability.scala</groupId>
    <artifactId>scala-starter-parent</artifactId>
    <version>1.14-SNAPSHOT</version>
    <packaging>pom</packaging>
      <dependencies>
        <!-- tests -->
        <dependency>
            <groupId>org.scalatest</groupId>
            <artifactId>scalatest_${scala.version}</artifactId>
            <version>${scala.test.version}</version>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.scala-lang/scala-library -->
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}.${scala.sub.version}</version>
        </dependency>
    </dependencies>

        <properties>
        <!-- Plugins Versions -->
        <scala.sub.version>8</scala.sub.version>
        <scala.version>2.11</scala.version>
        <scala.test.version>3.0.5</scala.test.version>
        <!-- we will use the below plugings later -->
        <scala-maven-plugin-version>4.3.1</scala-maven-plugin-version>
        <scalatest-maven-plugin-version>2.0.0</scalatest-maven-plugin-version>
        <maven-compiler-plugin-version>3.1</maven-compiler-plugin-version>
        <java-version>1.8</java-version>
        <maven-surefire-plugin-version>2.12.4</maven-surefire-plugin-version>
        <maven.assembly.plugin.version>3.1.0</maven.assembly.plugin.version>
    </properties>

</project>

Build, Compile, Execute Scala Unit testing, and Package the Jar using mvn package

Add scala plugin to allow maven to compile scala code

<build>
    <plugins>
        <!-- maven plugin for scala compiler -->
        <plugin>
            <!-- https://mvnrepository.com/artifact/net.alchim31.maven/scala-maven-plugin -->
            <groupId>net.alchim31.maven</groupId>
            <artifactId>scala-maven-plugin</artifactId>
            <version>${scala-maven-plugin-version}</version>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

At this stage maven is able to compile scala sources and tests. However, maven still didn't run the unit testing still 0 test run.

Add maven plugin for scala testing engine

Let's add maven plugin to run scala unit testing

<!-- maven plugin for scala testing engine -->
<plugin>
    <!-- https://mvnrepository.com/artifact/org.scalatest/scalatest-maven-plugin -->
    <groupId>org.scalatest</groupId>
    <artifactId>scalatest-maven-plugin</artifactId>
    <version>${scalatest-maven-plugin-version}</version>
    <executions>
        <execution>
            <goals>
                <goal>test</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Let's run and check the unit testing results. We can find that maven is able to run scala unit testing and provide the results.

Skip java compilation for main and test

As we saw in the previous logs maven still assume our project contains java code. So, we will inform maven to skip any compilation for main and test java code.

This can be achieved using maven-compiler-plugin.

<plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>${maven-compiler-plugin-version}</version>
          <configuration>
              <source>${java-version}</source>
              <target>${java-version}</target>
              <skipMain>true</skipMain> <!-- skip java compile -->
              <skip>true</skip> <!-- skip java testCompile -->
          </configuration>
</plugin>

Let's check the output. we can find that maven skips the java comilation for main and test classes Not compiling main sources & Not compiling test sources

Skip executing java unit testing

We can find the below part in the previous log which indicates that maven is trying to execute java unit testing in our code. Let's try to stop the below part which is not needed in our example.

We will add maven-surefire-plugin and skip java unit testing execution.

<!-- maven unit testing plugin-->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>${maven-surefire-plugin-version}/version>
    <configuration>
        <skipTests>true</skipTests>  <!-- skip java unit testing -->
    </configuration>
</plugin>

Let's run again and check the output. We can find that maven stop to execute java unit testing.

Packaging the jar

<!-- Maven Assembly for building Jar With Dependencies -->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>${maven.assembly.plugin.version}</version>
    <configuration>
        <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef> <!-- get the jar with dependencies -->
        </descriptorRefs>
        <archive>
            <manifest>
                <mainClass>com.gability.labs.cicd</mainClass> <!-- to inform the jar where is the main class demo the manifest without -->  
            </manifest>
        </archive>
        <appendAssemblyId>false</appendAssemblyId> <!-- to remove the descriptor from jar name --> 
    </configuration>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>single</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Add Scala static analysis tools.

Scoverage

Add code coverage tool for scala that offers statement and branch coverage Scoverage

 <!-- Maven scala coverage plugin -->
<plugin>
    <groupId>org.scoverage</groupId>
    <artifactId>scoverage-maven-plugin</artifactId>
    <version>${scoverage-plugin-version}</version>
    <configuration>
        <highlighting>true</highlighting>
        <minimumCoverage>${scoverage-minimumCoverage}</minimumCoverage>
        <failOnMinimumCoverage>true</failOnMinimumCoverage>
        <additionalForkedProjectProperties>skipTests=false</additionalForkedProjectProperties>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>check</goal>
            </goals>
            <phase>package</phase> <!-- must bind to a phase -->
        </execution>
    </executions>
</plugin>

Findbugs

<!-- findbugs-maven-plugin -->
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>findbugs-maven-plugin</artifactId>
    <version>${findbugs-maven-plugin-version}</version>
    <configuration>
        <effort>Max</effort>
        <threshold>High</threshold>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>check</goal>
            </goals>
        </execution>
    </executions>
</plugin>

ScalaStyle

  <!-- Scala Style-maven-plugin-->
<plugin>
    <groupId>org.scalastyle</groupId>
    <artifactId>scalastyle-maven-plugin</artifactId>
    <version>1.0.0</version>
    <configuration>
        <verbose>false</verbose>
        <failOnViolation>true</failOnViolation>
        <includeTestSourceDirectory>true</includeTestSourceDirectory>
        <failOnWarning>false</failOnWarning>
        <sourceDirectory>${project.basedir}/src/main/scala</sourceDirectory>
        <testSourceDirectory>${project.basedir}/src/test/scala</testSourceDirectory>
        <outputFile>${project.build.directory}/checkstyle-result.xml</outputFile>
        <inputEncoding>${project.build.sourceEncoding}</inputEncoding>
        <outputEncoding>${project.reporting.outputEncoding}</outputEncoding>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>check</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>org.scalastyle</groupId>
            <artifactId>scalastyle-maven-plugin</artifactId>
            <version>${scalastyle-maven-plugin-version}</version>
        </dependency>
    </dependencies>
</plugin>

Maven Reporting

<!-- Maven Reporting Site plugin-->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-site-plugin</artifactId>
    <version>${maven-site-plugin-version}</version>
</plugin>

<!-- Maven Surefire Report Plugin-->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-report-plugin</artifactId>
    <version>${maven-surefire-report-plugin-version}</version>
</plugin>
<!-- Maven Project Info Reports Plugin-->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-project-info-reports-plugin</artifactId>
    <version>${project-info-reports.plugin-version}</version>
</plugin>

Configure Parent

1. GitHub Parent repo scala-starter-parent

2. generate github developer tocken and give it access to parent and child token.

3. Add .m2/settings.xml

    <settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                            http://maven.apache.org/xsd/settings-1.0.0.xsd">
   
        <activeProfiles>
            <activeProfile>github</activeProfile>
        </activeProfiles>
   
        <profiles>
            <profile>
            <id>github</id>
            <repositories>
                <repository>
                <id>github-scala-starter-parent</id>
                <name>GitHub Garage Education scala-starter-parent Apache Maven Packages</name>
                <url>https://maven.pkg.github.com/garage-education/scala-starter-parent</url>
                </repository>
            </repositories>
            </profile>
        </profiles>
   
        <servers>
            <server>
            <id>github-scala-starter-parent</id>
            <username>YOUR_GITHUB_USERNAME</username>
            <password>YOUR_GENERATED_TOKEN</password>
            </server>
        </servers>
    </settings>

4. Add distributionManagement tag to parent

   <distributionManagement>
       <repository>
           <id>github-scala-starter-parent</id>
           <name>GitHub scala-starter-parent Apache Maven Packages</name>
           <url>https://maven.pkg.github.com/garage-education/scala-starter-parent</url>
       </repository>
   </distributionManagement>

5. Maven Deploy artifact mvn deploy

6. Add SCM tasgs to parent

       <scm>
           <connection>scm:git:https://github.com/garage-education/scala-starter-parent.git</connection>
           <developerConnection>scm:git:https://github.com/garage-education/scala-starter-parent.git</developerConnection>
           <url>https://github.com/garage-education/scala-starter-parent</url>
           <tag>HEAD</tag>
       </scm>

8. execute Maven Release mvn -B release:prepare release:perform check <project.scm.id>github-scala-starter-parent</project.scm.id>

Configure Child

1. GitHub Parent repo scala-sandbox

2. Add distributionManagement tag to parent

   <distributionManagement>
       <repository>
           <id>github-scala-sandbox</id>
           <name>GitHub scala-sandbox Apache Maven Packages</name>
           <url>https://maven.pkg.github.com/garage-education/scala-sandbox</url>
       </repository>
   </distributionManagement>

3. Add .m2/settings.xml

        <repositories>
            ...
            <repository>
            <id>github-scala-sandbox</id>
            <name>GitHub Garage Education scala-starter-parent Apache Maven Packages</name>
            <url>https://maven.pkg.github.com/garage-education/scala-sandbox</url>
            </repository>
        </repositories>
   
        <servers>
            ...
            <server>
            <id>github-scala-sandbox</id>
            <username>YOUR_GITHUB_USERNAME</username>
            <password>YOUR_GENERATED_TOKEN</password>
            </server>
        </servers>

4. Maven Deploy artifact mvn deploy

5. Add SCM tasgs to parent

       <scm>
           <connection>scm:git:https://github.com/garage-education/scala-sandbox.git</connection>
           <developerConnection>scm:git:https://github.com/garage-education/scala-sandbox.git</developerConnection>
           <url>https://github.com/garage-education/scala-sandbox</url>
           <tag>HEAD</tag>
       </scm>

7. execute Maven Release mvn -B release:prepare release:perform check <project.scm.id>github-sandbox</project.scm.id>

GitHub Actions scala-starter-parent

1. Add GitHub Action pipeline file .github/workflow/buil.yml

   # This workflow will build a Java project with Maven
   # For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
   
   name: Java CI with Maven
   
   on: [ push ]
   
   jobs:
   build:
       runs-on: ubuntu-latest
       steps:
       - uses: actions/checkout@v2
       - name: Set up JDK 1.8
           uses: actions/setup-java@v1
           with:
           java-version: 1.8
       - name: Cache Maven packages
           uses: actions/cache@v1
           with:
           path: ~/.m2
           key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
           restore-keys: ${{ runner.os }}-m2
       - name: Build with Maven
           run: mvn -B install
   publish:
       runs-on: ubuntu-latest
       steps:
       - uses: actions/checkout@v2
       - name: Set up JDK 1.8
           uses: actions/setup-java@v1
           with:
           java-version: 1.8
       - name: Publish package
           run: mvn -B deploy
           env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

1. GitHub Child repo scala-sandbox
2. Add SCM tasgs to child