rhubarb-lip-sync/rhubarb/lib/googletest/docs/quickstart-bazel.md

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# Quickstart: Building with Bazel
This tutorial aims to get you up and running with GoogleTest using the Bazel
build system. If you're using GoogleTest for the first time or need a refresher,
we recommend this tutorial as a starting point.
## Prerequisites
To complete this tutorial, you'll need:
* A compatible operating system (e.g. Linux, macOS, Windows).
* A compatible C++ compiler that supports at least C++11.
* [Bazel](https://bazel.build/), the preferred build system used by the
GoogleTest team.
See [Supported Platforms](platforms.md) for more information about platforms
compatible with GoogleTest.
If you don't already have Bazel installed, see the
[Bazel installation guide](https://docs.bazel.build/versions/master/install.html).
{: .callout .note}
Note: The terminal commands in this tutorial show a Unix shell prompt, but the
commands work on the Windows command line as well.
## Set up a Bazel workspace
A
[Bazel workspace](https://docs.bazel.build/versions/master/build-ref.html#workspace)
is a directory on your filesystem that you use to manage source files for the
software you want to build. Each workspace directory has a text file named
`WORKSPACE` which may be empty, or may contain references to external
dependencies required to build the outputs.
First, create a directory for your workspace:
```
$ mkdir my_workspace && cd my_workspace
```
Next, youll create the `WORKSPACE` file to specify dependencies. A common and
recommended way to depend on GoogleTest is to use a
[Bazel external dependency](https://docs.bazel.build/versions/master/external.html)
via the
[`http_archive` rule](https://docs.bazel.build/versions/master/repo/http.html#http_archive).
To do this, in the root directory of your workspace (`my_workspace/`), create a
file named `WORKSPACE` with the following contents:
```
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
name = "com_google_googletest",
urls = ["https://github.com/google/googletest/archive/609281088cfefc76f9d0ce82e1ff6c30cc3591e5.zip"],
strip_prefix = "googletest-609281088cfefc76f9d0ce82e1ff6c30cc3591e5",
)
```
The above configuration declares a dependency on GoogleTest which is downloaded
as a ZIP archive from GitHub. In the above example,
`609281088cfefc76f9d0ce82e1ff6c30cc3591e5` is the Git commit hash of the
GoogleTest version to use; we recommend updating the hash often to point to the
latest version.
Bazel also needs a dependency on the
[`rules_cc` repository](https://github.com/bazelbuild/rules_cc) to build C++
code, so add the following to the `WORKSPACE` file:
```
http_archive(
name = "rules_cc",
urls = ["https://github.com/bazelbuild/rules_cc/archive/40548a2974f1aea06215272d9c2b47a14a24e556.zip"],
strip_prefix = "rules_cc-40548a2974f1aea06215272d9c2b47a14a24e556",
)
```
Now you're ready to build C++ code that uses GoogleTest.
## Create and run a binary
With your Bazel workspace set up, you can now use GoogleTest code within your
own project.
As an example, create a file named `hello_test.cc` in your `my_workspace`
directory with the following contents:
```cpp
#include <gtest/gtest.h>
// Demonstrate some basic assertions.
TEST(HelloTest, BasicAssertions) {
// Expect two strings not to be equal.
EXPECT_STRNE("hello", "world");
// Expect equality.
EXPECT_EQ(7 * 6, 42);
}
```
GoogleTest provides [assertions](primer.md#assertions) that you use to test the
behavior of your code. The above sample includes the main GoogleTest header file
and demonstrates some basic assertions.
To build the code, create a file named `BUILD` in the same directory with the
following contents:
```
load("@rules_cc//cc:defs.bzl", "cc_test")
cc_test(
name = "hello_test",
size = "small",
srcs = ["hello_test.cc"],
deps = ["@com_google_googletest//:gtest_main"],
)
```
This `cc_test` rule declares the C++ test binary you want to build, and links to
GoogleTest (`//:gtest_main`) using the prefix you specified in the `WORKSPACE`
file (`@com_google_googletest`). For more information about Bazel `BUILD` files,
see the
[Bazel C++ Tutorial](https://docs.bazel.build/versions/master/tutorial/cpp.html).
Now you can build and run your test:
<pre>
<strong>my_workspace$ bazel test --test_output=all //:hello_test</strong>
INFO: Analyzed target //:hello_test (26 packages loaded, 362 targets configured).
INFO: Found 1 test target...
INFO: From Testing //:hello_test:
==================== Test output for //:hello_test:
Running main() from gmock_main.cc
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from HelloTest
[ RUN ] HelloTest.BasicAssertions
[ OK ] HelloTest.BasicAssertions (0 ms)
[----------] 1 test from HelloTest (0 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (0 ms total)
[ PASSED ] 1 test.
================================================================================
Target //:hello_test up-to-date:
bazel-bin/hello_test
INFO: Elapsed time: 4.190s, Critical Path: 3.05s
INFO: 27 processes: 8 internal, 19 linux-sandbox.
INFO: Build completed successfully, 27 total actions
//:hello_test PASSED in 0.1s
INFO: Build completed successfully, 27 total actions
</pre>
Congratulations! You've successfully built and run a test binary using
GoogleTest.
## Next steps
* [Check out the Primer](primer.md) to start learning how to write simple
tests.
* [See the code samples](samples.md) for more examples showing how to use a
variety of GoogleTest features.