Bazel test examples. ) Select this with: or .
Bazel test examples. Bazel supports large codebases across multiple repositories, and large numbers of users. bzl files are written in a dialect of Starlark properly known as the "Build Language", though it is often simply referred to as "Starlark", especially when emphasizing that a feature is expressed in the Build Language as opposed to being a built-in or "native" part of Bazel. awesome-bazel A curated list of Bazel rules, tooling and resources. In this post, we'll dive straight into the code examples and explore how to use the API to automate your build and testing processes. Apr 24, 2025 · A step-by-step guide to building, testing, and packaging a Python library with Bazel and the rules_python core library. /lib/BUILD. These examples will show you how to navigate and understand the build targets within a project's structure. While the Bazel user guide and user manual preach the benefits of giving Bazel full control over your build process by rewriting all build processes using Bazel-native rulesets (as Google reportedly does internally), this is an immense amount of work. Contribute to cdleary/bazel_pybind_sample development by creating an account on GitHub. May 3, 2021 · In the previous articles,we saw how to launch linter for python with a custom rule, and in the one be Tagged with bazel, python, pytest, pylint. For example, bazel build --test_env ODBCINI=foo //my:test For example, if the host OS is Linux and you run bazel build, Bazel picks up lines starting with build:linux. Attributes marked nonconfigurable in their documentation cannot use this feature. Apr 1, 2020 · In particular, if you want to just run one test or one test method (e. Jun 21, 2018 · I would like to query the data files (or runfiles) used for this test (in this case abc/abc. cc source file with no dependencies. We'll cover both the basic and advanced techniques, so you can be sure to find the information you need. Test sharding in Bazel is implemented by the runner, or put another way the executable that is called by the *_test rule. For illustration, we’ll begin with a multi-module Maven project and then build the source code using Bazel Unit testing with bazel using Java and C++ I created two example directories to show (on a very basic level) how bazel works with unit testing for java and c++. The documentation is here. Oct 10, 2019 · I have a my_module. 2 days ago · Bazel depends on toolchain support to enforce the inclusion checking rules. Requirements Requirements for an output directory layout: Doesn't collide if multiple users are building on the same box. Keywords and operators, when quoted, are treated as ordinary words. Along the way, you'll learn key Bazel concepts, such as targets and BUILD files. Others, like the py_test Oct 1, 2025 · Configuring the JVM used to execute and test the code Bazel uses one JDK for compilation and another JVM to execute and test the code. Normally I run the tests by cding into the Oct 1, 2025 · This page contains resources that help you use Bazel with C++ projects. For a quicker "hello world" example, see examples/hello. Oct 1, 2025 · The licenses can also be specified. It's intended for Developer Infrastructure and Build systems experts to study solutions to problems at scale. Oct 1, 2025 · This tutorial introduces you to the basics of Bazel by showing you how to build a Go (Golang) project. name _deploy. How can I pass such a flag to my test while running the test via bazel test command? For example: I can run a test multiple times using: baze Dec 13, 2024 · Bazel is a fast, scalable, and extensible build and test system that helps you manage complex codebases efficiently. It is typically tiny internal actions, such as creating symbolic links. The folder structure is pretty simple. So how was my life before I started writing Unit Tests? I was so afraid to refactor my codes. bzl%print_aspect would apply the print_aspect to the target example and all of the target rules that are accessible recursively via the deps attribute. java └── MODULE. Create and run a binary With your Bazel workspace set up, you can now use GoogleTest code within your own project. Oct 1, 2025 · Bazel can build and test code on a variety of hardware, operating systems, and system configurations, using many different versions of build tools such as linkers and compilers. To help manage this complexity, Bazel has a concept of constraints and platforms. May 8, 2025 · Uncover Build & Test Issues The following flags can help you better understand Bazel build or test errors. bazel file in the root of this repo. g. jar: A Java archive. If you haven’t already seen the previous blog post about what test sharding is, start here. cc in your my_workspace directory with the following contents: # include <gtest/gtest. Some runners, like the JUnit runner in rules_jvm have it implemented. Oct 1, 2025 · shutdown: Stops the Bazel server. Bazel searches for the JVM using JAVA_HOME or path. Set up a project workspace, which is a directory where Bazel looks for build inputs and BUILD files, and where it stores build outputs. Oct 1, 2025 · For example, if you as a rule writer have some debug mode that you'd like to turn on inside test rules, you don't want to give users the ability to indiscriminately turn on that feature inside other non-test rules. bazel help target-syntax: Explains the syntax for specifying targets. In this example there were 6 remote cache hits, and 2 actions did not have cache hits and were executed remotely. 4 · 8. For language and --output flag details, see the Bazel query reference and Bazel cquery reference manuals. Bazel examples and tutorials A collection of examples of how to use the Bazel build system. I was just plain dumb. Using ctx. greeting("Rust")); } } a fast, scalable, multi-language and extensible build system - bazelbuild/bazel Jun 15, 2018 · I have used gflags in my test to define custom flags. Bazel automates the process of compiling code, linking dependencies, running tests, and deploying artifacts. Just looking for a smaller Bazel repo as a playground? Run aspect init to Usage Run all Jest tests in the workspace: bazel test --test_lang_filters=jest // See jest_test API documentation and the example usages in the example folder. test: Builds and runs the specified test targets. Mar 9, 2025 · Introducing scasagrande/bazel-examples, a git repository hosting a variety of Bazel related examples for public reference. When quoting one or more target names, use only one type of quotes (either all single or In our example, the hello-world target instantiates Bazel's built-in cc_binary rule. In this little example I show a basic setup for visual studio to be able to start your own project. Oct 1, 2025 · java-tutorial ├── BUILD ├── src │ └── main │ └── java │ └── com │ └── example │ ├── cmdline │ │ ├── BUILD │ │ └── Runner. Oct 1, 2025 · Using Bazel To build or test a project with Bazel, you typically do the following: Set up Bazel. bazel file (we can use the example from rules_go as an inspiration): Oct 1, 2025 · Macros, for example, can't change their behavior based on the chosen branch, and bazel query can only make conservative guesses about a target's configurable dependencies. It uses a human-readable, high-level build language. The rule tells Bazel to build a self-contained executable binary from the hello-world. For example, some is a keyword but "some" is a word. In this case we want to test our rules as a package, so we need to define a target which would represent the rules_haskell distribution to pass it to the test. For this to work, limit_to_input_files attribute must be set to True as the against image file may contain other Protobuf files. Bazel supports projects in multiple languages and builds outputs for multiple platforms. You’ll also learn how to develop and run a basic application using Python with Bazel. Supports building in multiple workspaces at the same time. txt contains all keys and values where the key's name starts with STABLE_ bazel-out/volatile-status. There is a This ruleset is a high-performance Bazel integration for JavaScript, based on the pnpm package manager. txt) using bazel query. Oct 1, 2025 · This tutorial covers how to work with Bazel to trace dependencies in your code using a premade Bazel project. jar: A Java archive suitable for deployment. The specific format of the value to the flag depends on the test runner. We created a full guide for Scala and Java for you! Oct 6, 2021 · Our tutorial for the open-source tool Bazel shows to optimize and automate the build process of large-scale software. Oct 1, 2025 · Report an issue open_in_new View source open_in_new Nightly · 8. cc in your my_workspace directory with the following contents: This is a Bazel workspace that contains examples for the blogpost about tests. Start here if you're completely new to Bazel. txt contains the rest of the keys and their values If the contents of bazel-out/stable-status. Oct 1, 2025 · While Bazel is a build system that supports multi-language builds, this tutorial uses a C++ project as an example and provides the general guidelines and flow that apply to most languages. Fast: Bazel's sandbox only sees npm packages as directories, not individual Oct 20, 2019 · During bazel test You can use --test_env and those will be available during bazel test. bazel help startup_options: Options for the JVM hosting Bazel. This guide shows you how to print the output of tests in Bazel. Getting help bazel help command: Prints help and options for command. Hoping to learn Advanced Bazel concepts? Our Bazel 200-series courses use this repository as the example material. Oct 6, 2022 · Every Bazel rule requires its sources to be declared explicitly. html" %} This page covers the options that are available with various Bazel commands, such as bazel build, bazel run, and bazel test. However, be careful when using single or double quotes in target names. Bazel C++ Pybind11 Sample. Oct 1, 2025 · bazel build //MyExample:example --aspects print. For example there are no pathMapping issues with TypeScript rootDirs. Other users execute the test later to check whether the invariant has been broken. Oct 1, 2025 · sh_binary(name, deps, srcs, data, args, aspect_hints, compatible_with, deprecation, env, env_inherit, exec_compatible_with, exec_group_compatible_with, exec_properties, features, output_licenses, package_metadata, restricted_to, tags, target_compatible_with, testonly, toolchains, use_bash_launcher, visibility) The sh_binary rule is used to declare executable shell scripts. For a more detailed explanation please have a look at the official Oct 1, 2025 · This page contains resources that help you use Bazel with JavaScript projects. Documentation for bazel is here UNIT TESTING NOTES: I am using a symbolic link for my google unit test and a hard link for my junit test dependencies. Oct 1, 2025 · This page covers the options that are available with various Bazel commands, such as bazel build, bazel run, and bazel test. TEST (HelloTest, BasicAssertions) { // Expect two strings not to be equal. Download and install Bazel. Nov 8, 2023 · Explore two approaches for migrating Docker Compose tests to Bazel for better integration and test management. In this comprehensive guide, we’ll Note that in order to make hello-greet visible to hello-test, we have to add "//test:__pkg__", to the visibility attribute in . Jun 23, 2025 · This page covers the options that are available with various Bazel commands, such as bazel build, bazel run, and bazel test. Now you’re ready to build C++ code that uses GoogleTest. Correct: works seamlessly with node. Contribute to Mizux/bazel-pybind11 development by creating an account on GitHub. txt, a text file from the test_data package, so that other packages may use it, for example, in the data attribute of tests. js module resolution. Bazel supports Oct 1, 2025 · Report an issue open_in_new View source open_in_new Nightly · 8. This variety of examples demonstrate how a large polyglot monorepo is configured with Bazel. Supported OS identifiers are linux, macos, windows, freebsd, and openbsd. The test runner's main method is invoked instead of the main class being compiled. They use a syntax more flexible than labels, which is documented in Specifying targets to build. txt and def. bat scripts for trivial things. Write a BUILD file, which tells Bazel what to build and how to build it. It also contains package installation rules for integrating with PyPI and other indices. If the latter, the rule is a test rule, and the name of the rule must end in _test Dec 17, 2024 · Bazel is an open-source build and test tool that is particularly efficient for software development in large-scale environments, similar to other build automation tools like Make, Maven, and Gradle. It supports multiple languages, platforms, and frameworks, and can scale to handle large and Oct 1, 2025 · py_library(name, deps, srcs, data, aspect_hints, compatible_with, deprecation, distribs, exec_compatible_with, exec_group_compatible_with, exec_properties, experimental_venvs_site_packages, features, imports, licenses, package_metadata, precompile, precompile_invalidation_mode, precompile_optimize_level, precompile_source_retention, pyi_deps, pyi_srcs, restricted_to, srcs_version, tags, target a fast, scalable, multi-language and extensible build system - bazelbuild/bazel Jan 12, 2025 · If you write an application you don’t just want a hello-world to run, but also to test and debug it. The example directory contains the most basic examples with explicit loads and uses rules for scala and java directly. Local cache hits are not included in this summary. Bazel ensures fast builds by enabling caching and Jan 4, 2024 · Bazel is a powerful tool that helps you build, test, and deploy software faster and more reliably. It links to build rules and other information specific to building JavaScript with Bazel. version: Prints version information for Bazel. Example The following example exports golden. I wasn’t like that. If you want to a fast, scalable, multi-language and extensible build system - bazelbuild/bazel 2 hours ago · Running bazel test when no tests are built is an example where this could be useful. Jul 8, 2022 · Learn how to define unit tests in your Build file and then how to run your tests using Bazel. greeting, thing); } } #[cfg(test)] mod test { use super::Greeter; #[test] fn test_greeting() { let hello = Greeter::new("Hi"); assert_eq!("Hi Rust", hello. An example would help a lot. a fast, scalable, multi-language and extensible build system - bazelbuild/bazel Apr 28, 2018 · Writing unit tests for C++ with Bazel and GoogleTest 2 minute read 0 For last couple of months I am in love with writing Unit Tests. It supports projects in multiple languages and builds outputs for multiple platforms. Although this is closer to how Bazel operates, for this particular use case it isn't recommended. As an example, create a file named hello_test. (sh_binary is a Learn about Bazel's release model, latest releases, and compatibility policies. If you have not done so already, get started with building C++ projects with Bazel by completing the tutorial Introduction to Bazel: Build a C++ Project. How to print test output in Bazel Bazel is a build tool for C++ and other languages. It was originally developed to support the needs of Google, and it provides high performance and scalability for complex software projects. Implicit output targets name. Oct 1, 2025 · bazel query ' "//foo:bar=wiz" ' # single-quotes for shell, double-quotes for Bazel. With incremental build capabilities that recompile only what’s necessary and rich caching and Bazel then writes the key-value pairs into two files: bazel-out/stable-status. 6 Here you will find some of the most common use cases for building C++ projects with Bazel. A Mar 29, 2025 · Learn how Bazel's query tools can help you navigate complex projects, optimize builds, and make changes confidently as your codebase grows. Sep 18, 2023 · While there’s much to be said about writing test rules and frameworks that mesh well with Bazel, this post will focus on the experience of running tests as a developer with bazel test. Bazel cheatsheet This cheatsheet provides quick tips on how to build and test code in our repository using Bazel. Note that the example also relies on code in the /MODULE. We could just run it under yacce and after bazel reports it finished compiling of all tests, just cancel tests execution with Ctrl+C to let yacce proceed with compile_commands generation faster. In fact, Bazel Queries are a perfect tool to demonstrate how Oct 1, 2025 · This page covers the options that are available with various Bazel commands, such as bazel build, bazel run, and bazel test. 2 · 8. In this tutorial, we’ll go through the steps required to build a simple Java application using Bazel. Now you can use bazel test to run the test. txt change, Bazel invalidates the actions that depend on them. The --aspects flag takes one argument, which is a specification of the aspect in the format <extension file label>%<aspect top-level name>. By default Bazel compiles the code using a JDK it downloads and it executes and tests the code with the JVM installed on the local machine. Supports building for multiple target Aug 28, 2024 · Bazel's Python API provides a powerful way to automate these workflows and take advantage of remote execution capabilities. The original design documents for our Bazel build can be found at the following Golinks: go/skia-infra-bazel go/skia-infra-bazel-frontend go/skia-infra-bazel-backend Initial setup This section includes steps every engineer should follow Examples for Bazel. You may say I was adventurous, hardcore and love living … Aug 26, 2025 · Last modified: 18 August 2025 Bazel is an open-source build and test tool developed by Google. 6 This page covers requirements and layout for output directories. You can get help by typing bazel help query or bazel help cquery on the command line. View the Project on GitHub jin/awesome-bazel Awesome Bazel {Fast, Correct} - Choose two Bazel is an open-source build and test tool similar to Make, Maven, and Gradle. Documentation for rules_python is Build the project Review the dependency graph Refine your Bazel build Specify multiple build targets Use multiple packages Use labels to reference targets Further reading Before you begin To prepare for the tutorial, first Install Bazel if you don’t have it installed already. Options The This repository is the home of the core Python rules -- py_library, py_binary, py_test, py_proto_library, and related symbols that provide the basis for Python support in Bazel. This tutorial will help you get started with Bazel in IntelliJ IDEA. build_setting_value Like all rules, build setting rules have implementation functions. It links to a tutorial, build rules, and other information specific to building C++ projects with Bazel. Bazel queries and TARGET_PATTERN Target Pattern is a syntax used to specify a set of targets. Feb 9, 2025 · This post is going to go into more detail on how test sharding works in Bazel. The primary action is compiling Angular TypeScript including component templates, css and the various annotations such as @Injectable. Oct 1, 2025 · A java_test() rule compiles a Java test. Oct 1, 2025 · One user writes a test to assert an invariant which they expect to be maintained. Why should I use Bazel? Bazel offers the following advantages: High May 30, 2023 · Note that targets will be skipped only if all targets are requested to be built, using bazel build // or bazel test // for example. I will also explain the configuration, so you can make changes according to your needs. Oct 1, 2025 · For example test inherits from the build command, so all bazel build flags are valid for bazel test, and all build lines apply also to bazel test unless there's a test line for the same option. java │ ├── Greeting. h> // Demonstrate some basic assertions. A collection of projects built with Bazel. . 0 · 7. In the course Jan 8, 2024 · Bazel is an open-source tool for building and testing source code, similar to Maven and Gradle. Alternatively, a single buf_breaking_test can be used against each proto_library target. (Only built if explicitly requested. Oct 1, 2025 · See below for a minimal toy example, followed by an example that checks actions. See this FAQ for more on using select() with rules and macros. Objective Bazel overview Bazel is an open-source build and test tool similar to Make, Maven, and Gradle. Oct 1, 2025 · INFO: 11 processes: 6 remote cache hit, 3 internal, 2 remote. label_list(), }, ) This defines a rule kind named example_library. For example test inherits from the build command, so all bazel build flags are valid for bazel test, and all build lines apply also to bazel test unless there’s a test line for the same option. Get help in your IDE by typing bazel help query or bazel help cquery on the command line. Options The Oct 1, 2025 · This page covers the options that are available with various Bazel commands, such as bazel build, bazel run, and bazel test. The call to rule also must specify if the rule creates an executable output (with executable = True), or specifically a test executable (with test = True). It works with multi-language projects, offering support for C++, Java, Kotlin, Python, Rust, and other languages, and ensures consistent, reproducible builds across environments. Then, retrieve the sample project from Bazel’s GitHub repository: In our example, the hello-world target instantiates Bazel's built-in cc_binary rule. For information on cc_library and hdrs header Oct 1, 2025 · example_library = rule( implementation = _example_library_impl, attrs = { "deps": attr. using --test_filter), bazel will still build all the java_test 's dependencies. println!("{} {}", &self. It is designed to manage large codebases with complex dependencies across multiple languages and platforms. Target syntax Some commands, like build or test, can operate on a list of targets. For a language details and --output flag details, please see the reference manuals, Bazel query reference and Bazel cquery reference. Contribute to bazelbuild/examples development by creating an account on GitHub. In this article you’ll learn about Bazel, what it’s used for, and what features make this build tool so special. Both foo and "foo" are words. The 3 internal part can be ignored. bazel Build with Bazel Set up the workspace Before you can build a project, you need to set up its workspace. Oct 1, 2025 · Test rule examples: diff_test() (source, documentation): test that compares contents of two files native_test() (source, documentation): wraps a native binary in a *_test rule, which you can bazel test On Windows, consider using . Apr 29, 2018 · Writing unit tests for C++ with Bazel and GoogleTest For last couple of months I am in love with writing Unit Tests. Reference: ahumesky answer. 3 · 8. Engineered to streamline workflows, Bazel reduces build times, improves reliability, and ensures consistent, reproducible results across diverse environments—helping teams deliver high-quality software faster. Specifically, if you are integrating third-party software Commands and Options {% include "_buttons. py that does import my_module and runs some tests written with pytest on it. bat scripts. Nov 13, 2024 · A simple Bazel Query in practice In the following chapter, we will use TARGET_PATTERN syntax to demonstrate how Bazel queries work. Let’s create a filegroup in the top-level BUILD. Oct 1, 2025 · This page covers how to get started using Bazel's query language to trace dependencies in your code. py file that implements my_module and a file test_my_module. You'll learn how to set up your workspace, build a small program, import a library, and run its test. Feb 14, 2020 · To give a specific example for the default C++ testrunner (not the general "depends on which test runner you use"): For a test: EXPECT_EQ(. Oct 1, 2025 · The bazel test command respects this sort of organization: For an invocation like bazel test //some/test:suite, Bazel first enumerates all test targets transitively included by the //some/test:suite target (we call this "test_suite expansion"), then Bazel builds and tests those targets. Also, note that glob s only glob within a build package, and won't cross over into other packages. In order to run bazel you will need to download and install bazel. Options The Aug 30, 2022 · When Bazel is coordinating the actions the real benefits of Bazel will be seen such as parallelization, caching, test caching, remote execution/caching and all the other benefits that come with Bazel. If you are getting 0 processes (or a number lower than Simple example of using pybind11 via Bazel. You may say I was adventurous, hardcore and love living dangerous life! But that wasn’t the case, believe me. With your Bazel workspace set up, you can now use GoogleTest code within your own project. sh scripts, you can solve trivial tasks with . 8 You can set environment variables for test execution in bazel with the --test_env flag. The layering_check feature has to be supported by the toolchain and requested explicitly, for example via the --features=layering_check command-line flag or the features parameter of the package function. You'll want to use --test_filter. Oct 21, 2020 · Bazel is a powerful yet complicated system, and it can be intimidating to newcomers. A test is a binary wrapper around your test code. If you're new to Bazel, read Bazel Tutorial: Build a Go Project, which introduces Bazel concepts and shows you how to set up a small Go workspace to be built with Bazel. Jan 27, 2023 · Regardless of the programming language or platform, with Bazel, developers can create and test the entire source code with a single command. If a specific target is built and is incompatible, the build will fail. For an example that generates build files and retrieves external dependencies using Gazelle, see examples/basic_gazelle. java │ └── ProjectRunner. Bazel is an advanced, open-source build and test automation tool designed to handle the demands of modern, large-scale software development. See the module vs package mode example for a concrete example of the differences. Instead of . Lazy: only fetches/installs npm packages needed for the requested build/test targets. Contribute to bmuschko/bazel-examples development by creating an account on GitHub. ) Select this with: or . Jun 29, 2023 · Bazel Testing provides developers with a reliable approach to validate their code. Dec 2, 2023 · Bazel is an open source software tool developed by Google and used to automate software builds and test softwares for large projects with multi language dependencies. 1 · 8. This page is a companion to the list of Bazel's commands in Build with Bazel. ) Oct 1, 2025 · Bazel's BUILD and . lfb 00ybe jambe me app8k ok0xf ns nx4 8yae 6ho
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