jacoco:prepare-agent

Full name :

org.jacoco:jacoco-maven-plugin:0.8.13-SNAPSHOT:prepare-agent

Description :

Prepares a property pointing to the JaCoCo runtime agent that can be passed as a VM argument to the application under test. Depending on the project packaging type by default a property with the following name is set:

tycho.testArgLine for packaging type eclipse-test-plugin and
argLine otherwise.

If your project already defines VM arguments for test execution, be sure that they will include property defined by JaCoCo.

One of the ways to do this in case of maven-surefire-plugin - is to use syntax for late property evaluation :

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <configuration>
      <argLine>@{argLine} -your -extra -arguments</argLine>
    </configuration>
  </plugin>

You can define empty property to avoid JVM startup error Could not find or load main class @{argLine} when using late property evaluation and jacoco-maven-plugin not executed.

Another way is to define "argLine" as a Maven property rather than as part of the configuration of maven-surefire-plugin:

  <properties>
    <argLine>-your -extra -arguments</argLine>
  </properties>
  ...
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <configuration>
      <!-- no argLine here -->
    </configuration>
  </plugin>

Resulting coverage information is collected during execution and by default written to a file when the process terminates.

Attributes :

Requires a Maven project to be executed.
Requires dependency resolution of artifacts in scope: runtime .
The goal is thread-safe and supports parallel builds.
Since version: 0.5.3 .
Binds by default to the lifecycle phase : initialize .

Optional Parameters

Name	Type	Since	Description
`<address>`	`String`	`0.5.3`	IP address or hostname to bind to when the output method is tcpserver or connect to when the output method is tcpclient. In tcpserver mode the value "" causes the agent to accept connections on any local address. User property is* : `jacoco.address` .
`<append>`	`Boolean`	`0.5.3`	If set to true and the execution data file already exists, coverage data is appended to the existing file. If set to false, an existing execution data file will be replaced. User property is : `jacoco.append` .
`<classDumpDir>`	`File`	`0.5.3`	If a directory is specified for this parameter the JaCoCo agent dumps all class files it processes to the given location. This can be useful for debugging purposes or in case of dynamically created classes for example when scripting engines are used. User property is : `jacoco.classDumpDir` .
`<destFile>`	`File`	`0.5.3`	Path to the output file for execution data. Default value is : `${project.build.directory}/jacoco.exec` . User property is : `jacoco.destFile` .
`<dumpOnExit>`	`Boolean`	`0.5.3`	If set to true coverage data will be written on VM shutdown. User property is : `jacoco.dumpOnExit` .
`<exclClassLoaders>`	`String`	`0.5.3`	A list of class loader names, that should be excluded from execution analysis. The list entries are separated by a colon (:) and may use wildcard characters (* and ?). This option might be required in case of special frameworks that conflict with JaCoCo code instrumentation, in particular class loaders that do not have access to the Java runtime classes. User property is : `jacoco.exclClassLoaders` .
`<excludes>`	`List`	`0.5.3`	A list of class names to exclude from instrumentation. May use wildcard characters (* and ?). When not specified nothing will be excluded. Except for performance optimization or technical corner cases this option is normally not required. If you want to exclude classes from the report please configure the `report` goal accordingly.
`<inclBootstrapClasses>`	`Boolean`	`0.5.3`	Specifies whether also classes from the bootstrap classloader should be instrumented. Use this feature with caution, it needs heavy includes/excludes tuning. User property is : `jacoco.inclBootstrapClasses` .
`<inclNoLocationClasses>`	`Boolean`	`0.5.3`	Specifies whether classes without source location should be instrumented. User property is : `jacoco.inclNoLocationClasses` .
`<includes>`	`List`	`0.5.3`	A list of class names to include in instrumentation. May use wildcard characters (* and ?). When not specified everything will be included.
`<jmx>`	`Boolean`	`0.5.3`	If set to true the agent exposes functionality via JMX. User property is : `jacoco.jmx` .
`<output>`	`String`	`0.5.3`	Output method to use for writing coverage data. Valid options are: file: At VM termination execution data is written to a file. tcpserver: The agent listens for incoming connections on the TCP port specified by the `address` and `port` . Execution data is written to this TCP connection. tcpclient: At startup the agent connects to the TCP port specified by the `address` and `port` . Execution data is written to this TCP connection. none: Do not produce any output. User property is : `jacoco.output` .
`<port>`	`Integer`	`0.5.3`	Port to bind to when the output method is tcpserver or connect to when the output method is tcpclient. In tcpserver mode the port must be available, which means that if multiple JaCoCo agents should run on the same machine, different ports have to be specified. User property is : `jacoco.port` .
`<propertyName>`	`String`	`0.5.3`	Allows to specify property which will contains settings for JaCoCo Agent. If not specified, then "argLine" would be used for "jar" packaging and "tycho.testArgLine" for "eclipse-test-plugin". User property is : `jacoco.propertyName` .
`<sessionId>`	`String`	`0.5.3`	A session identifier that is written with the execution data. Without this parameter a random identifier is created by the agent. User property is : `jacoco.sessionId` .
`<skip>`	`boolean`	`0.5.3`	Flag used to suppress execution. Default value is : `false` . User property is : `jacoco.skip` .

Parameter Details

<address>

IP address or hostname to bind to when the output method is tcpserver or connect to when the output method is tcpclient. In tcpserver mode the value "*" causes the agent to accept connections on any local address.

Type : java.lang.String
Since : 0.5.3
Required : No
User Property : jacoco.address

<append>

If set to true and the execution data file already exists, coverage data is appended to the existing file. If set to false, an existing execution data file will be replaced.

Type : java.lang.Boolean
Since : 0.5.3
Required : No
User Property : jacoco.append

<classDumpDir>

If a directory is specified for this parameter the JaCoCo agent dumps all class files it processes to the given location. This can be useful for debugging purposes or in case of dynamically created classes for example when scripting engines are used.

Type : java.io.File
Since : 0.5.3
Required : No
User Property : jacoco.classDumpDir

<destFile>

Path to the output file for execution data.

Type : java.io.File
Since : 0.5.3
Required : No
User Property : jacoco.destFile
Default : ${project.build.directory}/jacoco.exec

<dumpOnExit>

If set to true coverage data will be written on VM shutdown.

Type : java.lang.Boolean
Since : 0.5.3
Required : No
User Property : jacoco.dumpOnExit

<exclClassLoaders>

A list of class loader names, that should be excluded from execution analysis. The list entries are separated by a colon (:) and may use wildcard characters (* and ?). This option might be required in case of special frameworks that conflict with JaCoCo code instrumentation, in particular class loaders that do not have access to the Java runtime classes.

Type : java.lang.String
Since : 0.5.3
Required : No
User Property : jacoco.exclClassLoaders

<excludes>

A list of class names to exclude from instrumentation. May use wildcard characters (* and ?). When not specified nothing will be excluded. Except for performance optimization or technical corner cases this option is normally not required. If you want to exclude classes from the report please configure the report goal accordingly.

Type : java.util.List
Since : 0.5.3
Required : No

<inclBootstrapClasses>

Specifies whether also classes from the bootstrap classloader should be instrumented. Use this feature with caution, it needs heavy includes/excludes tuning.

Type : java.lang.Boolean
Since : 0.5.3
Required : No
User Property : jacoco.inclBootstrapClasses

<inclNoLocationClasses>

Specifies whether classes without source location should be instrumented.

Type : java.lang.Boolean
Since : 0.5.3
Required : No
User Property : jacoco.inclNoLocationClasses

<includes>

A list of class names to include in instrumentation. May use wildcard characters (* and ?). When not specified everything will be included.

Type : java.util.List
Since : 0.5.3
Required : No

<jmx>

If set to true the agent exposes functionality via JMX.

Type : java.lang.Boolean
Since : 0.5.3
Required : No
User Property : jacoco.jmx

<output>

Output method to use for writing coverage data. Valid options are:

file: At VM termination execution data is written to a file.
tcpserver: The agent listens for incoming connections on the TCP port specified by the address and port . Execution data is written to this TCP connection.
tcpclient: At startup the agent connects to the TCP port specified by the address and port . Execution data is written to this TCP connection.
none: Do not produce any output.

Type : java.lang.String
Since : 0.5.3
Required : No
User Property : jacoco.output

<port>

Port to bind to when the output method is tcpserver or connect to when the output method is tcpclient. In tcpserver mode the port must be available, which means that if multiple JaCoCo agents should run on the same machine, different ports have to be specified.

Type : java.lang.Integer
Since : 0.5.3
Required : No
User Property : jacoco.port

<propertyName>

Allows to specify property which will contains settings for JaCoCo Agent. If not specified, then "argLine" would be used for "jar" packaging and "tycho.testArgLine" for "eclipse-test-plugin".

Type : java.lang.String
Since : 0.5.3
Required : No
User Property : jacoco.propertyName

<sessionId>

A session identifier that is written with the execution data. Without this parameter a random identifier is created by the agent.

Type : java.lang.String
Since : 0.5.3
Required : No
User Property : jacoco.sessionId

<skip>

Flag used to suppress execution.

Type : boolean
Since : 0.5.3
Required : No
User Property : jacoco.skip
Default : false