NPE during install-node-and-npm

Do you want to request a feature or report a bug?

Bug

What is the current behavior?

[INFO] --- frontend-maven-plugin:1.2:install-node-and-npm (install-node-and-npm) @ am-theme ---
[INFO] Node v4.6.0 was installed, but we need version v6.9.1
[INFO] Installing node version v6.9.1
[INFO] Unpacking C:\Users\mriehema\.m2\repository\com\github\eirslett\node\6.9.1\node-6.9.1-win-x64.zip into C:\dev\node\tmp
[INFO] Copying node binary from C:\dev\node\tmp\node-v6.9.1-win-x64\node.exe to C:\dev\node\node.exe
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 01:02 min
[INFO] Finished at: 2016-11-15T15:57:03+01:00
[INFO] Final Memory: 560M/1470M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal com.github.eirslett:frontend-maven-plugin:1.2:install-node-and-npm (install-node-and-npm) on project am-theme: Execution install-node-and-npm of goal com.github.eirslett:frontend-maven-plugin:1.2:install-node-and-npm failed. NullPointerException -> [Help 1]

If the current behavior is a bug, please provide the steps to reproduce.

• Install node 4.x via frontend-maven-plugin with explicit npmVersion
• Change version in pom.xml to 6.91without npmVersion
• Run mvn install again

What is the expected behavior?

The old one should be replaced.

Please mention your frontend-maven-plugin and operating system version.

• Win7, x64
• frontend-maven-plugin 1.2
• JDK8
• Maven 3.3.9

Old Config:

        <plugin>
          <groupId>com.github.eirslett</groupId>
          <artifactId>frontend-maven-plugin</artifactId>
          <version>1.1</version>
          <configuration>
            <nodeVersion>v4.6.0</nodeVersion> <!-- LTS -->
            <npmVersion>3.10.8</npmVersion>
          </configuration>
          <executions>
              <execution>
                <id>install-node-and-npm</id>
                <goals>
                  <goal>install-node-and-npm</goal>
                </goals>
              </execution>
            </execution>
        </plugin>

New config:

        <plugin>
          <groupId>com.github.eirslett</groupId>
          <artifactId>frontend-maven-plugin</artifactId>
          <version>1.2</version>
          <configuration>
            <nodeVersion>v6.9.1</nodeVersion><!-- LTS -->
            <!-- use bundled npm -->
          </configuration>
          <executions>
              <execution>
                <id>install-node-and-npm</id>
                <goals>
                  <goal>install-node-and-npm</goal>
                </goals>
              </execution>
            </execution>
        </plugin>

[mriehema]

You can delete the node folder manually as a workaround. But we should fix this.

[chrisrink]

This looks like an issue with the File.renameTo() method.

frontend-plugin-core/src/main/java/com/github/eirslett/maven/plugins/frontend/lib/NodeInstaller.java:222

I see a comment in stackoverflow to try File.move()

String fileName = "MyFile.txt";

try {
    Files.move(new File(fileName).toPath(), new File(fileName).toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
} catch (IOException ex) {
    Logger.getLogger(SomeClass.class.getName()).log(Level.SEVERE, null, ex);
}

https://stackoverflow.com/questions/1000183/reliable-file-renameto-alternative-on-windows.

Not sure if anyone has tried this.