Cannot run program "npm" in directory

Question

When i am traversing the to src/main/app/ folder structure where i have the package.JSON & gruntfile, i am able to run npm install and grunt command. But when i am trying to run the mvn jetty:run and a property file in the root folder of the project when POM file is present, it is throwing error that it cannot run npm install in the folder structure src/main/app/.

This is the exact error:

[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (n
pminstall) on project my-abc-web: Command execution failed. Cannot
 run program "npm" (in directory "C:\Users\Achyut_J01\Documents\GitHub\infras\my-abc\my-abc-web\src\main\app"): CreatePro
cess error=2, The system cannot find the file specified -> [Help 1]

It's a Windows Machine.

Answer 1

I used this workaround to have a cross-platform Maven build : declare the npm executable name as a Maven variable, and use Maven filters to modify this executable name when running on Windows.

It can work the same for Grunt, Bower etc.

This workaround is not necessary any more if you use exec-maven-plugin >=1.6.0 (thanks Manmay for the information in the comments): it was a bug of this plugin (see https://github.com/mojohaus/exec-maven-plugin/issues/42), that has been fixed in 1.6.0 (see https://github.com/mojohaus/exec-maven-plugin/pull/46)

<properties>
    <npm.executable>npm</npm.executable>
</properties>

(...)

<build>
    <plugins>
        (...)
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.5.0</version>
            <executions>
                <execution>
                    <id>exec-npm</id>
                    <phase>process-resources</phase>
                    <configuration>
                        <executable>${npm.executable}</executable>
                        <arguments>
                            <argument>install</argument>
                        </arguments>
                    </configuration>
                    <goals>
                        <goal>exec</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
        (...)
    </plugins>
</build>
<profiles>
    <profile>
        <id>platform-windows</id>
        <activation>
            <os>
                <family>windows</family>
            </os>
        </activation>
        <properties>
            <!-- Override the executable names for Windows -->
            <npm.executable>npm.cmd</npm.executable>
            <grunt.executable>grunt.cmd</grunt.executable>
            <bower.executable>bower.cmd</bower.executable>
        </properties>
    </profile>
</profiles>