1# How to submit a bug report 2 3If you received an error message, please include it and any exceptions. 4 5We commonly need to know what platform you are on: 6 7* JDK/JRE version (i.e., `java -version`) 8* Operating system (i.e., `uname -a`) 9 10# How to contribute 11 12We definitely welcome patches and contributions to OpenCensus! Here are 13some guidelines and information about how to do so. 14 15## Before getting started 16 17In order to protect both you and ourselves, you will need to sign the 18[Contributor License Agreement](https://cla.developers.google.com/clas). 19 20[Eclipse](https://google-styleguide.googlecode.com/svn/trunk/eclipse-java-google-style.xml) 21and 22[IntelliJ](https://google-styleguide.googlecode.com/svn/trunk/intellij-java-google-style.xml) 23style configurations are commonly useful. For IntelliJ 14, copy the style to 24`~/.IdeaIC14/config/codestyles/`, start IntelliJ, go to File > Settings > Code 25Style, and set the Scheme to `GoogleStyle`. 26 27## Style 28We follow the [Google Java Style 29Guide](https://google.github.io/styleguide/javaguide.html). Our 30build automatically will provide warnings for simple style issues. 31 32Run the following command to format all files. This formatter uses 33[google-java-format](https://github.com/google/google-java-format): 34 35### OS X or Linux 36 37`./gradlew goJF` 38 39### Windows 40 41`gradlew.bat goJF` 42 43We also follow these project-specific guidelines: 44 45### Javadoc 46 47* All public classes and their public and protected methods MUST have javadoc. 48 It MUST be complete (all params documented etc.) Everything else 49 (package-protected classes, private) MAY have javadoc, at the code writer's 50 whim. It does not have to be complete, and reviewers are not allowed to 51 require or disallow it. 52* Each API element should have a `@since` tag specifying the minor version when 53 it was released (or the next minor version). 54* There MUST be NO javadoc errors. 55* See 56 [section 7.3.1](https://google.github.io/styleguide/javaguide.html#s7.3.1-javadoc-exception-self-explanatory) 57 in the guide for exceptions to the Javadoc requirement. 58* Reviewers may request documentation for any element that doesn't require 59 Javadoc, though the style of documentation is up to the author. 60* Try to do the least amount of change when modifying existing documentation. 61 Don't change the style unless you have a good reason. 62 63### AutoValue 64 65* Use [AutoValue](https://github.com/google/auto/tree/master/value), when 66 possible, for any new value classes. Remember to add package-private 67 constructors to all AutoValue classes to prevent classes in other packages 68 from extending them. 69 70## Building opencensus-java 71 72Continuous integration builds the project, runs the tests, and runs multiple 73types of static analysis. 74 75Run the following commands to build, run tests and most static analysis, and 76check formatting: 77 78### OS X or Linux 79 80`./gradlew clean assemble check verGJF` 81 82### Windows 83 84`gradlew.bat clean assemble check verGJF` 85 86Use these commands to run Checker Framework null analysis: 87 88### OS X or Linux 89 90`./gradlew clean assemble -PcheckerFramework` 91 92### Windows 93 94`gradlew.bat clean assemble -PcheckerFramework` 95 96### Checker Framework null analysis 97 98OpenCensus uses the [Checker Framework](https://checkerframework.org/) to 99prevent NullPointerExceptions. Since the project uses Java 6, and Java 6 doesn't 100allow annotations on types, all Checker Framework type annotations must be 101[put in comments](https://checkerframework.org/manual/#backward-compatibility). 102Putting all Checker Framework annotations and imports in comments also avoids a 103dependency on the Checker Framework library. 104 105OpenCensus uses `org.checkerframework.checker.nullness.qual.Nullable` for all 106nullable annotations on types, since `javax.annotation.Nullable` cannot be 107applied to types. However, it uses `javax.annotation.Nullable` in API method 108signatures whenever possible, so that the annotations can be uncommented and 109be included in .class files and Javadocs. 110 111### Checkstyle import control 112 113This project uses Checkstyle to specify the allowed dependencies between 114packages, using its ImportControl feature 115(http://checkstyle.sourceforge.net/config_imports.html#ImportControl). 116`buildscripts/import-control.xml` specifies the allowed imports and contains 117some guidelines on OpenCensus' inter-package dependencies. An error messsage 118such as 119`Disallowed import - edu.umd.cs.findbugs.annotations.SuppressFBWarnings. [ImportControl]` 120could mean that `import-control.xml` needs to be updated. 121 122## Benchmarks 123 124### Invoke all benchmarks on a sub-project 125 126```bash 127$ ./gradlew clean :opencensus-impl-core:jmh 128``` 129 130### Invoke on a single benchmark class 131 132```bash 133./gradlew -PjmhIncludeSingleClass=BinaryFormatImplBenchmark clean :opencensus-impl-core:jmh 134``` 135 136### Debug compilation errors 137When you make incompatible changes in the Benchmarks classes you may get compilation errors which 138are related to the old code not being compatible with the new code. Some of the reasons are: 139* Any plugin cannot delete the generated code (jmh generates code) because if the user configured 140the directory as the same as source code the plugin will delete users source code. 141* After you run jmh, a gradle daemon will stay alive which may cache the generated code in memory 142and use use that generated code even if the files were changed. This is an issue for classes 143generated with auto-value. 144 145Run this commands to clean the Gradle's cache: 146```bash 147./gradlew --stop 148rm -fr .gradle/ 149rm -fr benchmarks/build 150``` 151 152## Proposing changes 153 154Create a Pull Request with your changes. Please add any user-visible changes to 155CHANGELOG.md. The continuous integration build will run the tests and static 156analysis. It will also check that the pull request branch has no merge commits. 157When the changes are accepted, they will be merged or cherry-picked by an 158OpenCensus core developer. 159