gitflow-incremental-builder

A maven extension for incremental building of multi-module projects when using feature branches (Git Flow). Builds or tests only changed maven modules compared to reference branch in Git (e.g. origin/develop) and all their dependents.

Usage
- Disable in IDE
Example
Configuration

Usage

Add into maven pom file:

<build>
    <extensions>
        <extension>
            <groupId>com.vackosar.gitflowincrementalbuilder</groupId>
            <artifactId>gitflow-incremental-builder</artifactId>
            <version>3.7</version>
        </extension>
    </extensions>
    ...
</build>

Disable in IDE

As IDEs like IntelliJ IDEA or Eclipse usually apply their own custom strategy to building changed modules, this extension should be disabled in such environments to avoid inconsistencies or errors (e.g. see issue #49).

See gib.enabled in the configuration section.

Example

Maven project parent has two submodules child1 and child2:

$ ls *
pom.xml

child1:
pom.xml  src

child2:
pom.xml  src

parent has gitflow-incremental-builder configured:

$ cat 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>parent</groupId>
    <artifactId>parent</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <properties>
        <gib.referenceBranch>refs/heads/develop</gib.referenceBranch>
    </properties>

    <modules>
        <module>child1</module>
        <module>child2</module>
    </modules>

    <build>
        <extensions>
            <extension>
                <groupId>com.vackosar.gitflowincrementalbuilder</groupId>
                <artifactId>gitflow-incremental-builder</artifactId>
                <version>3.7</version>
            </extension>
        </extensions>
    </build>

</project>

Currently checked out branch is feature. There is also a branch develop:

$ git branch
  develop
* feature

Branches are the same now:

$ git diff develop

Thus incremental does not build and test anything:

$ mvn test
[INFO] Scanning for projects...
[INFO] gitflow-incremental-builder starting...
[INFO] Git dir is: C:\Users\Vaclav\IdeaProjects\gitflow-incremental-builder\tmp\example\.git
[INFO] Head of branch HEAD is commit of id: commit 17b09f1f9ee9d2a56b7d7bf43d319db529cade9e 1483112738 -----p
[INFO] Head of branch refs/heads/develop is commit of id: commit 17b09f1f9ee9d2a56b7d7bf43d319db529cade9e 1483112738 -----p
[INFO] Using merge base of id: commit 17b09f1f9ee9d2a56b7d7bf43d319db529cade9e 1483112738 -tr-sp
[INFO] ------------------------------------------------------------------------
[INFO] Changed Artifacts:
[INFO]
[INFO]
[INFO] No changed artifacts to build. Executing validate goal only.
[INFO] gitflow-incremental-builder exiting...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] child1
[INFO] child2
[INFO] parent
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building child1 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building child2 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building parent 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] child1 ............................................. SUCCESS [  0.002 s]
[INFO] child2 ............................................. SUCCESS [  0.001 s]
[INFO] parent ............................................. SUCCESS [  0.000 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.953 s
[INFO] Finished at: 2016-12-30T16:56:35+01:00
[INFO] Final Memory: 9M/162M
[INFO] ------------------------------------------------------------------------

Now a file is written and added to git control making branches different:

$ echo "text" > child1/src/main/java/file1.txt
$ git add child1/src/main/java/file1.txt
$ git diff develop
diff --git a/child1/src/main/java/file1.txt b/child1/src/main/java/file1.txt
new file mode 100644
index 0000000..8e27be7
--- /dev/null
+++ b/child1/src/main/java/file1.txt
@@ -0,0 +1 @@
+text
warning: LF will be replaced by CRLF in child1/src/main/java/file1.txt.
The file will have its original line endings in your working directory.

Thus incremental build builds and tests only child1:

$ mvn test
[INFO] Scanning for projects...
[INFO] gitflow-incremental-builder starting...
[INFO] Git dir is: C:\Users\Vaclav\IdeaProjects\gitflow-incremental-builder\tmp\example\.git
[INFO] Head of branch HEAD is commit of id: commit 17b09f1f9ee9d2a56b7d7bf43d319db529cade9e 1483112738 -----p
[INFO] Head of branch refs/heads/develop is commit of id: commit 17b09f1f9ee9d2a56b7d7bf43d319db529cade9e 1483112738 -----p
[INFO] Using merge base of id: commit 17b09f1f9ee9d2a56b7d7bf43d319db529cade9e 1483112738 -tr-sp
[INFO] ------------------------------------------------------------------------
[INFO] Changed Artifacts:
[INFO]
[INFO] child1
[INFO]
[INFO] gitflow-incremental-builder exiting...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building child1 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ child1 ---
[WARNING] Using platform encoding (Cp1250 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory C:\Users\Vaclav\IdeaProjects\gitflow-incremental-builder\tmp\example\child1\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ child1 ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding Cp1250, i.e. build is platform dependent!
[INFO] Compiling 1 source file to C:\Users\Vaclav\IdeaProjects\gitflow-incremental-builder\tmp\example\child1\target\classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ child1 ---
[WARNING] Using platform encoding (Cp1250 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory C:\Users\Vaclav\IdeaProjects\gitflow-incremental-builder\tmp\example\child1\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ child1 ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding Cp1250, i.e. build is platform dependent!
[INFO] Compiling 1 source file to C:\Users\Vaclav\IdeaProjects\gitflow-incremental-builder\tmp\example\child1\target\test-classes
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ child1 ---
[INFO] Surefire report directory: C:\Users\Vaclav\IdeaProjects\gitflow-incremental-builder\tmp\example\child1\target\surefire-reports

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running ATest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.041 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.043 s
[INFO] Finished at: 2016-12-30T17:01:56+01:00
[INFO] Final Memory: 18M/167M
[INFO] ------------------------------------------------------------------------

Configuration

Maven pom properties configuration with default values is below:

<properties>
	<gib.enabled>true</gib.enabled>
	<gib.repositorySshKey></gib.repositorySshKey>
	<gib.disableBranchComparison>false</gib.disableBranchComparison>
	<gib.referenceBranch>refs/remotes/origin/develop</gib.referenceBranch>
	<gib.baseBranch>HEAD</gib.baseBranch>
	<gib.uncommited>true</gib.uncommited>
	<gib.untracked>true</gib.untracked>
	<gib.skipTestsForNotImpactedModules>false</gib.skipTestsForNotImpactedModules>
	<gib.argsForNotImpactedModules></gib.argsForNotImpactedModules>
	<gib.buildAll>false</gib.buildAll>
	<gib.forceBuildModules></gib.forceBuildModules>
	<gib.excludeTransitiveModulesPackagedAs></gib.excludeTransitiveModulesPackagedAs>
	<gib.compareToMergeBase>true</gib.compareToMergeBase>
	<gib.fetchBaseBranch>false</gib.fetchBaseBranch>
	<gib.fetchReferenceBranch>false</gib.fetchReferenceBranch>
	<gib.excludePathRegex>(?!x)x</gib.excludePathRegex>
	<gib.failOnMissingGitDir>true</gib.failOnMissingGitDir>
	<gib.failOnError>true</gib.failOnError>
</properties>

gib.enabled

Can be used to disable this extension temporarily or permanently (e.g. to avoid clashes with IDE building strategy).

gib.disableBranchComparison

Disables the comparison between baseBranch and referenceBranch. This property should be enabled if only uncommitted and/or untracked files shall be detected to only build projects that have been changed since the last commit in the current branch (see gib.uncommited and gib.untracked). The following properties are not evaluated when gib.disableBranchDiff is enabled:

gib.referenceBranch
gib.compareToMergeBase
gib.fetchReferenceBranch
gib.excludePathRegex

gib.uncommited

Detects changed files that have not yet been committed. This does not include untracked files (see git status manual).

gib.untracked

Detects files that are not yet tracked by git (see git status manual). This does not include uncommitted files. A new file is not untracked anymore after it is added to the index.

gib.skipTestsForNotImpactedModules

In conjunction with -am or gib.buildAll=true this property disables the compilation/execution of tests for modules that have not been changed by adding maven.test.skip=true. In case a not impacted module produces a test jar just the test execution is disbled via skipTests=true.

Can be combined with gib.argsForNotImpactedModules.

gib.argsForNotImpactedModules

In conjunction with -am or gib.buildAll=true this property allows adding arguments/properties for modules that have not been changed to futher reduce overhead, e.g. skip Checkstyle or Enforcer plugin. Arguments have to be sparated with a single space character and values are optional. Example:

mvn clean install -am -Dgib.argsForNotImpactedModules='-Denforcer.skip -Dcheckstyle.skip=true'

Can be combined with gib.skipTestsForNotImpactedModules.

gib.forceBuildModules

Defines artifact ids of modules to build forcibly, even if these modules have not been changed and/or do not depend on changed modules. Example:

mvn clean install -Dgib.forceBuildModules=unchanged-module-1,unchanged-module-2

Regular expressions are also supported in each comma separated part, e.g.:

mvn clean install -Dgib.forceBuildModules=unchanged-module-.*,another-module

Each of these modules is subject to argsForNotImpactedModules and skipTestsForNotImpactedModules.

This property has no effect in case buildAll is enabled.

gib.excludeTransitiveModulesPackagedAs

Defines the packaging (e.g. jar) of modules that depend on changed modules but shall not be built.

One possible use case for this is mainly working in an IDE, fixing all compile errors etc. and then just quickly building the least possible amount of modules which are needed to (hot-)deploy the changes via mvn on the command line. In this scenario, by defining -Dgib.excludeTransitiveModulesPackagedAs=jar,pom, only the directly changed jar modules and the dependent war and/or ear deployment modules will be built.

This property has no effect in case buildAll is enabled and an exclusion might be overriden by gib.forceBuildModules.

Requirements

Maven version 3+.

OrDTesters/gitflow-incremental-builder

README