Use Spotless for formatting (DataDog/dd-trace-java#1619)

Author: tylerbenson

.editorconfig

@@ -663,10 +663,8 @@ ij_groovy_while_brace_force = never
 ij_groovy_while_on_new_line = false
 ij_groovy_wrap_long_lines = false
 
-[{*.gradle.kts,*.kt,*.kts,*.main.kts}]
-indent_size = 4
-tab_width = 4
-ij_continuation_indent_size = 8
+[{*.kt,*.kts}]
+ij_continuation_indent_size = 2
 ij_kotlin_align_in_columns_case_branch = false
 ij_kotlin_align_multiline_binary_operation = false
 ij_kotlin_align_multiline_extends_list = false

.githooks/pre-commit

@@ -0,0 +1,14 @@
+#!/bin/bash
+# http://redsymbol.net/articles/unofficial-bash-strict-mode/
+set -euo pipefail
+IFS=$'\n\t'
+
+if ! ./gradlew spotlessCheck; then
+  ./gradlew spotlessApply
+  echo ""
+  echo ""
+  echo -e "\033[0;33mCode has been formatted; please git diff/add and recommit."
+  echo ""
+  echo ""
+  exit 1
+fi

CONTRIBUTING.md

@@ -83,8 +83,8 @@ Gradle plugin.
 #### Snapshot builds
 
 For developers testing code changes before a release is complete, there are
-snapshot builds of the `master` branch. They are available from 
-[JFrog OSS repository](https://oss.jfrog.org/artifactory/oss-snapshot-local/io/opentelemetry/auto/) 
+snapshot builds of the `master` branch. They are available from
+[JFrog OSS repository](https://oss.jfrog.org/artifactory/oss-snapshot-local/io/opentelemetry/auto/)
 
 #### Building from source
 
@@ -145,31 +145,34 @@ We follow the [Google Java Style
 Guide](https://google.github.io/styleguide/javaguide.html). Our build will
 fail if source code is not formatted according to that style.
 
-To verify code style manually run the following command, which uses
-[google-java-format](https://github.com/google/google-java-format) library:
+The main goal is to avoid extensive reformatting caused by different IDEs having different opinion
+about how things should be formatted by establishing.
 
-`./gradlew verifyGoogleJavaFormat`
+Running
 
-or on Windows
+```bash
+./gradlew spotlessApply
+```
 
-`gradlew.bat verifyGoogleJavaFormat`
+reformats all the files that need reformatting.
 
-Instead of fixing style inconsistencies by hand, you can run gradle task
-`googleJavaFormat` to automatically fix all found issues:
+Running
 
-`./gradlew googleJavaFormat`
+```bash
+./gradlew spotlessCheck
+```
 
-or on Windows
-
-`gradlew.bat googleJavaFormat`
+runs formatting verify task only.
 
 #### Pre-commit hook
 
-To completely delegate code style formatting to the machine, you can add [git
-pre-commit hook](https://git-scm.com/docs/githooks). We provide an example
-script in `buildscripts/pre-commit` file. Just copy or symlink it into
-`.git/hooks` folder.
+To completely delegate code style formatting to the machine,
+there is a pre-commit hook setup to verify formatting before committing.
+It can be activated with this command:
 
+```bash
+git config core.hooksPath .githooks
+```
 
 #### Editorconfig
 

README.md

@@ -10,8 +10,8 @@
 
 This project provides a Java agent JAR that can be attached to any Java 7+
 application and dynamically injects bytecode to capture telemetry from a
-number of popular libraries and frameworks. 
-The telemetry data can be exported in a variety of formats. 
+number of popular libraries and frameworks.
+The telemetry data can be exported in a variety of formats.
 In addition, the agent and exporter can be configured via command line arguments
 or environment variables. The net result is the ability to gather telemetry
 data from a Java application without code changes.
@@ -29,11 +29,11 @@ The instrumentation agent is enabled using the `-javaagent` flag to the JVM.
 java -javaagent:path/to/opentelemetry-auto-all.jar \
      -jar myapp.jar
 ```
-By default OpenTelemetry Java agent uses 
+By default OpenTelemetry Java agent uses
 [OTLP exporter](https://github.com/open-telemetry/opentelemetry-java/tree/master/exporters/otlp)
-configured to send data to 
+configured to send data to
 [OpenTelemetry collector](https://github.com/open-telemetry/opentelemetry-collector/blob/master/receiver/otlpreceiver/README.md)
-at `localhost:55680`. 
+at `localhost:55680`.
 
 Configuration parameters are passed as Java system properties (`-D` flags) or
 as environment variables (see below for full list). For example:
@@ -67,7 +67,7 @@ A simple wrapper for the Zipkin exporter of opentelemetry-java. It POSTs json in
 |----------------------------------|----------------------------------|----------------------------------------------------------------------|
 | ota.exporter=zipkin              | OTA_EXPORTER=zipkin              | To select Zipkin exporter                                            |
 | ota.exporter.zipkin.endpoint     | OTA_EXPORTER_ZIPKIN_ENDPOINT     | The Zipkin endpoint to connect to. Currently only HTTP is supported. |
-| ota.exporter.zipkin.service.name | OTA_EXPORTER_ZIPKIN_SERVICE_NAME | The service name of this JVM instance    
+| ota.exporter.zipkin.service.name | OTA_EXPORTER_ZIPKIN_SERVICE_NAME | The service name of this JVM instance
 
 #### OTLP exporter
 
@@ -94,7 +94,7 @@ attributes to stdout. It is used mainly for testing and debugging.
 *This is highly advanced behavior and still in the prototyping phase. It may change drastically or be removed completely. Use
 with caution*
 
-The OpenTelemetry API exposes SPI [hooks](https://github.com/open-telemetry/opentelemetry-java/blob/master/api/src/main/java/io/opentelemetry/trace/spi/TracerProviderFactory.java) 
+The OpenTelemetry API exposes SPI [hooks](https://github.com/open-telemetry/opentelemetry-java/blob/master/api/src/main/java/io/opentelemetry/trace/spi/TracerProviderFactory.java)
 for customizing its behavior, such as the `Resource` attached to spans or the `Sampler`.
 
 Because the auto instrumentation runs in a separate classpath than the instrumented application, it is not possible for customization in the application to take advantage of this customization. In order to provide such customization, you can
@@ -163,7 +163,7 @@ For this reason the following instrumentations are disabled by default:
 - `jdbc-datasource` which creates spans whenever `java.sql.DataSource#getConnection` method is called.
 - `servlet-filter` which creates spans around Servlet Filter methods.
 - `servlet-service` which creates spans around Servlet methods.
- 
+
 To enable them, add `ota.integration.<name>.enabled` system property:
 `-Dota.integration.jdbc-datasource.enabled=true`
 

RELEASING.md

@@ -9,7 +9,7 @@ to calculate the current version based on git tags. This plugin looks for the la
 
 ## Snapshot builds
 Every successful CI build of the master branch automatically executes `./gradlew snapshot` as the last task.
-This signals Nebula plugin to build and publish to 
+This signals Nebula plugin to build and publish to
 [JFrog OSS repository](https://oss.jfrog.org/artifactory/oss-snapshot-local/io/opentelemetry/auto/)next _minor_ release version.
 This means version `vX.(Y+1).0-SNAPSHOT`.
 
@@ -23,12 +23,12 @@ Do the following:
 On new tag creation a CI will start a new release build.
 It will do the following:
 - Checkout requested tag.
-- Run `./gradlew -Prelease.useLastTag=true final`. 
-This signals Nebula plugin to build `X.Y.0` version and to publish it to 
+- Run `./gradlew -Prelease.useLastTag=true final`.
+This signals Nebula plugin to build `X.Y.0` version and to publish it to
 [Bintray repository](https://bintray.com/open-telemetry/maven/opentelemetry-java-instrumentation).
 
 ## Patch releases
 Whenever a fix is needed to any older branch, a PR should be made into the corresponding maintenance branch.
 When that PR is merge, CI will notice the new commit into maintenance branch and will initiate a new build for this.
 That build, after usual building and checking, will run `./gradlew -Prelease.scope=patch final`.
-This will signal Nebula plugin to build a new version `vX.Y.(Z+1)` and publish it to Bintray repo. 
+This will signal Nebula plugin to build a new version `vX.Y.(Z+1)` and publish it to Bintray repo.

build.gradle

@@ -8,14 +8,11 @@ plugins {
   id 'org.unbroken-dome.test-sets' version '2.2.1'
   id 'com.github.ben-manes.versions' version '0.27.0'
 
-  // Not applying google java format by default because it gets confused by stray java build
-  // files in 'workspace' build directory in CI
-  id 'com.github.sherter.google-java-format' version '0.8' apply false
   id 'com.dorongold.task-tree' version '1.5'
 
   id "com.github.johnrengelman.shadow" version "5.2.0"
 
-  id "com.diffplug.gradle.spotless" version "3.28.1"
+  id "com.diffplug.gradle.spotless" version "4.3.0"
   id "com.github.spotbugs" version "4.0.1"
 }
 
@@ -67,3 +64,19 @@ task writeMuzzleTasksToFile {
       .join('\n')
   }
 }
+
+apply plugin: 'com.diffplug.gradle.spotless'
+
+spotless {
+  // this formatting is applied at the root level, as some of these files are not in a submodules
+  // and would be missed otherwise
+  format 'misc', {
+    target '**/.gitignore', '**/*.md', '**/*.sh'
+    indentWithSpaces()
+    trimTrailingWhitespace()
+    endWithNewline()
+  }
+}
+
+task formatCode(dependsOn: ['spotlessApply'])
+check.dependsOn 'spotlessCheck'

buildSrc/build.gradle.kts

@@ -1,6 +1,7 @@
 plugins {
   groovy
   `java-gradle-plugin`
+  id("com.diffplug.gradle.spotless") version "4.3.0"
 }
 
 gradlePlugin {

buildscripts/pre-commit

@@ -34,15 +34,3 @@ check.dependsOn checkstyleTasks
 tasks.withType(Test).configureEach {
   mustRunAfter checkstyleTasks
 }
-
-// Verification seems broken on Java 9.
-apply plugin: 'com.github.sherter.google-java-format'
-
-googleJavaFormat {
-  source = sourceSets*.allJava
-  exclude '**/build/**/*.java'
-}
-
-tasks.withType(Checkstyle).configureEach {
-  mustRunAfter verifyGoogleJavaFormat
-}

gradle/checkstyle.gradle

@@ -0,0 +1,12 @@
+# Disable formatting errors
+ignoreFormatterProblems=true
+org.eclipse.jdt.core.formatter.tabulation.char=space
+org.eclipse.jdt.core.formatter.tabulation.size=2
+org.eclipse.jdt.core.formatter.indentation.size=1
+org.eclipse.jdt.core.formatter.indentation.text_block_indentation=indent by one
+org.eclipse.jdt.core.formatter.indent_empty_lines=false
+org.eclipse.jdt.core.formatter.continuation_indentation=1
+org.eclipse.jdt.core.formatter.continuation_indentation_for_array_initializer=1
+groovy.formatter.longListLength=50
+groovy.formatter.multiline.indentation=1
+groovy.formatter.remove.unnecessary.semicolons=true

gradle/enforcement/spotless-groovy.properties

@@ -2,16 +2,23 @@ apply plugin: 'com.diffplug.gradle.spotless'
 
 spotless {
   java {
+    googleJavaFormat()
     licenseHeaderFile rootProject.file('gradle/enforcement/spotless.license.java'), '(package|import|public)'
     target 'src/**/*.java'
   }
   groovy {
     licenseHeaderFile rootProject.file('gradle/enforcement/spotless.license.java'), '(package|import|class)'
   }
   scala {
+    scalafmt()
     licenseHeaderFile rootProject.file('gradle/enforcement/spotless.license.java'), '(package|import|public)'
   }
   kotlin {
+    // ktfmt() // only supports 4 space indentation
+    ktlint().userData(['indent_size': '2', 'continuation_indent_size': '2'])
     licenseHeaderFile rootProject.file('gradle/enforcement/spotless.license.java'), '(package|import|public)'
   }
 }
+
+task formatCode(dependsOn: ['spotlessApply'])
+check.dependsOn 'spotlessApply'