<replacementProperty> fails to work with an empty <value> tag

[toolforger]

Describe the bug

Tried to eliminate the -SNAPSHOT suffix from git.build.version, using an empty <value> tag.
The plugin would not apply the rule in that case (which does not make any sense).

Steps to Reproduce; Expected and Observed Behaviour

Given a tag of "10.0-SNAPSHOT", this produces git.build.version.nosnapshot=10.1 as intended:

           <plugin>
                <groupId>pl.project13.maven</groupId>
                <artifactId>git-commit-id-plugin</artifactId>
                <version>2.2.5</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>revision</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <replacementProperties>
                        <replacementProperty>
                            <property>git.build.version</property>
                            <token>(.)-SNAPSHOT$</token> <!-- workaround: detect any character -->
                            <value>$1</value> <!-- workaround: have a nonempty <value> tag -->
                            <propertyOutputSuffix>nosnapshot</propertyOutputSuffix>
                        </replacementProperty>
                    </replacementProperties>
                </configuration>
            </plugin>

If I use

                            <token>-SNAPSHOT$</token>
                            <value></value>

or

                            <token>-SNAPSHOT$</token>
                            <value/>

I get git.build.version.nosnapshot=10.1-SNAPSHOT, i.e. the replacement is not happening.

No error messages or stack traces.

Additional context

For reproducibility please provide the following:

JDK Version: 1.8.0_152
Maven Version: 3.3.9
OS Info: Arch: amd64 Family: windows Name: windows 7 Version: 6.1
Running as a Maven build inside IntelliJ 2018.2; command line is C:\Daten\software\jdk-8u152-windows-x64\bin\java.exe -Dmaven.multiModuleProjectDirectory=C:\develop\id-gui -Dmaven.home=C:\Users\tkd6u\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\182.4505.22\plugins\maven\lib\maven3 -Dclassworlds.conf=C:\Users\tkd6u\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\182.4505.22\plugins\maven\lib\maven3\bin\m2.conf -javaagent:C:\Users\tkd6u\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\182.4505.22\lib\idea_rt.jar=64767:C:\Users\tkd6u\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\182.4505.22\bin -Dfile.encoding=UTF-8 -classpath C:\Users\tkd6u\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\182.4505.22\plugins\maven\lib\maven3\boot\plexus-classworlds-2.5.2.jar org.codehaus.classworlds.Launcher -Didea.version=2018.2.4 --errors --update-snapshots compile

[toolforger]

Note that the workaround above won't work if a property is to be completely replaced with an empty string.
Fingers crossed - I hope I won't need an empty property.

[TheSnoozer]

Hi, thanks for reporting your issue/problem here.
Unfortunately I fear that's maven's fault and a similar issue as outlined in #374.

The root issue I think is that maven just doesn't manage to tell the plugin the right settings (e.g. in that case the plugin doesn't even see that you have set the property to something empty).

Related Maven issues:

• https://issues.apache.org/jira/browse/MNG-6434
• https://issues.apache.org/jira/browse/MNG-5725

In fact the only thing i can do is actually suggest a similar workaround (#374 (comment)) and make the snapshot optional:

<replacementProperties>
                <replacementProperty>
                            <property>git.build.version</property>
                            <token>^(.*)(-SNAPSHOT)?$</token>
                            <value>$1</value>
                            <propertyOutputSuffix>nosnapshot</propertyOutputSuffix>
                </replacementProperty>
</replacementProperties>

[toolforger]

Well, the workaround didn't work out in the end, so this is still unsolved for me.
What about making <value> an empty string by default? Then specifying it empty or not at all doesn't make a difference. Sure it can create surprising behaviour, but well this is Maven anyway.

[TheSnoozer]

Right,
I should have tested the regex :')
In all fairness there are plenty of way to remove the optional ending string, its just a matter of finding the "right" regex.

See here for some inspiration how to get this working:

• https://regex101.com/r/bA2Tlx/1/
• https://regex101.com/r/bPFBwi/1/
• https://regex101.com/r/wTJXhO/1/

You can for example specify the regex with CDATA-Tags:

<token><![CDATA[^([^-SNAPSHOT]*)(.*)$]]></token>

[toolforger]

This issue is not about the regex.
It is about <value>: You cannot specify an empty replacement string.

[TheSnoozer]

Yeah I understand that. My suggested workaround is to build a regex that matches everything besides -SNAPSHOT that will also make use of regex groups to then eliminate the -SNAPSHOT (optional) suffix from git.build.version. Essentially use the power of regex to create a substring.

<replacementProperties>
                <replacementProperty>
                            <property>git.build.version</property>
                            <token><![CDATA[^([^-SNAPSHOT]*)(.*)$]]></token>
                            <value>$1</value>
                            <propertyOutputSuffix>nosnapshot</propertyOutputSuffix>
                </replacementProperty>
</replacementProperties>

Seems to work perfectly fine.

[TheSnoozer]

Hi thanks again for opening an issue for this.
This has now been addressed by #400 and will become available with the next 3.0 release.