Mason

Mason is a Maven extension that provides alternative model readers for Maven POM files, supporting multiple formats including:

• YAML
• JSON5
• TOML (limited support)
• HOCON (limited support)

Requirements

• Java 17+
• Maven 4.0.0-rc-3+

Usage

Add the extension to your Maven installation:

<extension>
  <groupId>eu.maveniverse.maven.mason</groupId>
  <artifactId>mason</artifactId>
  <version>0.2.0</version>
</extension>

Then you can use alternative formats for your POM files:

YAML Example (pom.yaml)

modelVersion: 4.0.0
parent: org.apache.maven.extensions:maven-extensions:43
id: org.apache.maven.extensions:maven-yaml-extension:1.0.0-SNAPSHOT
packaging: jar
dependencyManagement:
  dependencies:
    - org.junit:junit-bom:5.12.0@import
dependencies:
  - org.apache.maven:maven-api-spi:${maven.version}@provided
  - org.apache.maven:maven-api-core:${maven.version}@provided
  - org.junit.jupiter:junit-jupiter-api@test
build:
  plugins:
    - id: org.codehaus.modello:modello-maven-plugin:2.1.1
      executions:
        - id: generate-yaml-reader
          goals: [velocity]
          phase: generate-sources
          configuration:
            version: 4.2.0
            models: ['target/dependency/maven-api-model-${maven.version}.mdo']
            templates: ['src/mdo/map-model-reader.vm']
            params: ["packageModelV4=org.apache.maven.api.model"]

JSON Example (pom.json)

{
  "modelVersion": "4.0.0",
  "parent": "org.apache.maven.extensions:maven-extensions:43",
  "id": "org.apache.maven.extensions:maven-yaml-extension:1.0.0-SNAPSHOT",
  "packaging": "jar",
  "dependencyManagement": {
    "dependencies": [
      "org.junit:junit-bom:5.12.0@import"
    ]
  },
  "dependencies": [
    "org.apache.maven:maven-api-spi:${maven.version}@provided",
    "org.apache.maven:maven-api-core:${maven.version}@provided",
    "org.junit.jupiter:junit-jupiter-api@test"
  ],
  "build": {
    "plugins": [
      {
        "id": "org.codehaus.modello:modello-maven-plugin:2.1.1",
        "executions": [
          {
            "id": "generate-yaml-reader",
            "goals": [
              "velocity"
            ],
            "phase": "generate-sources",
            "configuration": {
              "version": "4.2.0",
              "models": [
                "target/dependency/maven-api-model-${maven.version}.mdo"
              ],
              "templates": [
                "src/mdo/map-model-reader.vm"
              ],
              "params": [
                "packageModelV4=org.apache.maven.api.model"
              ]
            }
          }
        ]
      }
    ]
  }
}

HOCON Example (pom.conf or pom.hocon)

⚠️ Warning: Advanced HOCON features like substitutions (${...}), includes, and object merging are not supported.

modelVersion: 4.0.0
parent: "org.apache.maven.extensions:maven-extensions:43"
id: "org.apache.maven.extensions:maven-yaml-extension:1.0.0-SNAPSHOT"
packaging: jar
dependencyManagement: {
  dependencies: [
    "org.junit:junit-bom:5.12.0@import"
  ]
}
dependencies: [
  "org.apache.maven:maven-api-spi:${maven.version}@provided",
  "org.apache.maven:maven-api-core:${maven.version}@provided",
  "org.junit.jupiter:junit-jupiter-api@test"
]
build {
  plugins: [
    {
      id: "org.codehaus.modello:modello-maven-plugin:2.1.1"
      executions: [
        {
          id: generate-yaml-reader
          goals: [
            velocity
          ]
          phase: generate-sources
          configuration {
            version: 4.2.0
            models: [
              "target/dependency/maven-api-model-${maven.version}.mdo"
            ]
            templates: [
              src/mdo/map-model-reader.vm
            ]
            params: [
              "packageModelV4=org.apache.maven.api.model"
            ]
          }
        }
      ]
    }
  ]
}

TOML Example (pom.toml)

⚠️ Warning: Location tracking (line numbers in error messages) is not supported for TOML files.

modelVersion = "4.0.0"
parent = "org.apache.maven.extensions:maven-extensions:43"
id = "org.apache.maven.extensions:maven-yaml-extension:1.0.0-SNAPSHOT"
packaging = "jar"
dependencyManagement.dependencies = [
  "org.junit:junit-bom:5.12.0@import"
]
dependencies = [
  "org.apache.maven:maven-api-spi:${maven.version}@provided",
  "org.apache.maven:maven-api-core:${maven.version}@provided",
  "org.junit.jupiter:junit-jupiter-api@test"
]
[build]
  [[build.plugins]]
    id = "org.codehaus.modello:modello-maven-plugin:2.1.1"
    [[build.plugins.executions]]
      id = "generate-yaml-reader"
      goals = ["velocity"]
      phase = "generate-sources"
      [build.plugins.executions.configuration]
        version = "4.2.0"
        models = ["target/dependency/maven-api-model-${maven.version}.mdo"]
        templates = ["src/mdo/map-model-reader.vm"]
        params = ["packageModelV4=org.apache.maven.api.model"]

Building

mvn clean install

License

Eclipse Public License, Version 2.0

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.