BT is a Build Tool

With the aims to fix all the problems with Maven Gradle :)

Aims:

reliable
fast

Principles:

Convention over configuration.
Work avoidance.

How is this tool different?

(a) Event Based With Concurrent Tasks

BT builds by having a set of tasks that are triggered by events. The initial event in SourceCodeFound and can trigger other tasks such as CopyResources which result in a ResourcesCopied event.

Events end up on a queue and are dispatched as quickly as possible. This means that, unlike Maven or Gradle, tasks as well as projects can run concurrently.

(b) Decomposed Configuration

Configuration is defined in the format of the tool. Projects are defined by project.json

{
  "artifact": "bt:bt:1.0.15-SNAPSHOT",
  "modules": [
    "src/api",
    "src/main",
    "src/junit4-support",
    "src/test"
  ]
}

Projects are composed of modules defined by module.json:

{
  "dependencies": [
    ":api",
    "org.slf4j:slf4j-api:1.7.25",
    "ch.qos.logback:logback-classic:1.2.3",
    "com.google.googlejavaformat:google-java-format:1.6",
    "com.puppycrawl.tools:checkstyle:8.12",
    "com.fasterxml.jackson.core:jackson-databind:2.9.4",
    "javax.inject:javax.inject:1"
  ]
}

Dependencies are defined in dependencies.json, this is a bit rubbish and needs to be improved:

{
  "org.slf4j:slf4j-api:1.7.25": [],
  "ch.qos.logback:logback-classic:1.2.3": [
    "ch.qos.logback:logback-core:1.2.3"
  ],
  "ch.qos.logback:logback-core:1.2.3": [],
  "com.google.googlejavaformat:google-java-format:1.6": [
    "com.google.guava:guava:22.0",
    "com.google.errorprone:javac-shaded:9+181-r4173-1"
  ],
  "com.google.guava:guava:22.0": [
    "com.google.code.findbugs:jsr305:1.3.9",
    "com.google.errorprone:error_prone_annotations:2.0.18",
    "com.google.j2objc:j2objc-annotations:1.1",
    "org.codehaus.mojo:animal-sniffer-annotations:1.14"
  ],
  "com.google.errorprone:javac-shaded:9+181-r4173-1": [],
  "com.puppycrawl.tools:checkstyle:8.12": [
    "antlr:antlr:2.7.7",
    "org.antlr:antlr4-runtime:4.7.1",
    "commons-beanutils:commons-beanutils:1.9.3",
    "commons-cli:commons-cli:1.4",
    "net.sf.saxon:Saxon-HE:9.8.0-12"
  ],
  "antlr:antlr:2.7.7": [],
  "org.antlr:antlr4-runtime:4.7.1": [],
  "commons-beanutils:commons-beanutils:1.9.3": [
    "commons-logging:commons-logging:1.2",
    "commons-collections:commons-collections:3.2.2"
  ],
  "commons-logging:commons-logging:1.2": [],
  "commons-collections:commons-collections:3.2.2": [],
  "commons-cli:commons-cli:1.4": [],
  "net.sf.saxon:Saxon-HE:9.8.0-12": [],
  "com.fasterxml.jackson.core:jackson-databind:2.9.4": [
    "com.fasterxml.jackson.core:jackson-annotations:2.9.0",
    "com.fasterxml.jackson.core:jackson-core:2.9.4"
  ],
  "com.fasterxml.jackson.core:jackson-annotations:2.9.0": [],
  "com.fasterxml.jackson.core:jackson-core:2.9.4": [],
  "javax.inject:javax.inject:1": [],
  "junit:junit:4.12": [
    "org.hamcrest:hamcrest-core:1.3"
  ],
  "org.hamcrest:hamcrest-core:1.3": []
}

Modules are named after the directory they are found in and can only the same group ID as the project.

Otherwise, there is no special configuration. For example:

Want to use check-style? Include your checkstyle.xml file in the module root.
Want to have a main-class? Include resources/MANIFEST.MF in your source code tree.

Oh yeah - no XML by default.

(c) Opinionated

All code is passed via checkstyle and automatically formatted.

(d) Tests Are Just Modules

Maven and Gradle treat tests as part of a module. BT treats does not have separate test sources. Tests are just modules that define the tests as classes in META-INF/annotations/org.junit.Test (oh yeah - only JUnit support and only version 4).

(e) Logging

Logs of the build are dumped into target/build.log, not the console.

(f) Not Such Thing As A Clean Build

Nope. If you want a clean build:

find . -name target | xargs -Rf

How can I write a task for BT?

Implement the bt.api.Task interface and add yourself to META-INF/services/bt.api.Task. To recieve an event, create a method annotated with @Subscribe taking a single argument, the event type.

SLF4J is used for logging. Log at debug level to write to build.log.

alexec / build-tool