Bazel is seriously amazing. The learning curve to use bazel is a bit steep, but once justinsb and I got it running in kops: Holy Cow Batman! Kops tests and builds are so much faster. When cached, build times are sub-second which took 6 min. Those numbers are no joke. See this link for information on their logo. On February 25th,a Googler pushed the first comment to the Bazel project, and Google officially Open Sourced the project. Bazel is a build tool that replaces using Makefiles or other tools for building go.
Under the hood, it uses go build ; but it is not your average build tool. Just as make has many different options, Bazel provides many exciting features including dependency management, and templating with external tools, and the capability to build containers without docker. Create your project with your source control tool of choice. Inside your project, run the bash script provided here. Provide the go path for the project. For example: create-bazel-workspace github.
The above script will seed a project to use cobra. I have provided an example project located here on Github. The above script creates two files. This file typically contains references to external build rules and project dependencies. The syntax quite similar to Groovy, and you can see the go dependencies being added to the Workspace.
From Bazel documentation :. Thankfully the Bazel authors have added Gazelle. More documentation about Gazelle. One thing that Gazelle did not do initially was define a rule to build a binary. The example Makefile contains the usual suspects for Bazel commands. The usual workflows for development: build, test, and Gazelle for Bazel.
Bazel is powerful. You can do cool things like running external targets, and building containers without docker, a heck of a lot faster than docker does it!
Cross-compiling with Bazel is complicated, and the support for making Linux binaries on OSX is limited. One solution is to use a container such as planter. I am planning on further posts about using go-bindata and containers with Bazel once we have those fixed in kops. We need to integrate Bazel into kops testing with Travis.
One note, use caching inside your CI tool.The complexity of automating the process of building, assembling and distributing the source code and binaries for any medium- to large-sized project is high. Make files and shell script can be powerful tools but they do not provide any support for strong modeling of a domain, are hard to maintain and do not provide any means to testing the automation code.
Gradle currently does not provide a standard way to build Go project with its core distribution. However, users can write plugins to enhance the functionality by plugins to model new domains. GoGradle is a plugin that helps with compiling, testing and assembling Go projects. For a deep dive on the plugin functionality check out the recording of the Summit talk on GoGradle. Disclaimer: I found another Gradle plugin for building Go project but did not have a chance to compare the functionality and their implementation approaches.
Functionally, Link Verifier recursively iterates over a given directory and identifies plain-text mark-up files like AsciiDoc and Markdown. The project depends on external Go packages: xurls for extract URLs out of a text document and testify for conviently making assertions in test code.
Both libraries can be resolved with the help of Glidea package manager for Go. A developer working on the project will have to install Glide to properly resolve the declared dependencies and their transitive dependencies. Additionally, code coverage metrics are produced by configuring the The test command. The project uses Codecov to capture and visualize code coverage metrics over time. The program was designed to run on different OSes e.
For that purpose the project publishes prebuilt libraries with every single release. To adhere to the license agreements of external packages used by the project, I also wrote some logic for extracting the third-party license agreements and packaging them with the corresponding library in a TAR or ZIP file.
Most of the automation steps mentioned above can be executed by invoking a shell script. Every change made to the project runs through Travis CI. You can find the source code describe below in a dedicated branch. Getting started with the GoGradle plugin is easy. We just have to create a build.
In the build script, apply the plugin and provide some basic configuration that indicates the root path of the package used for the project. For the Link Verifier project, I assigned github. All sections below directly refer to version 0.
By default the GoGradle plugin downloads the latest version of Go automatically and stores it in a temporary directory. Alternatively, a user can also configure a concrete Go version as needed. Please refer to the plugin documentation for more information. Now that we applied the plugin to our project, we have a bunch of useful tasks to our disposal.
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Learn more. Bazel Golang combined coverage report Ask Question. Asked 10 days ago. Active 10 days ago. Viewed 43 times. There were tests whose specified size is too big. INFO: Analyzed 52 targets 0 packages loaded, targets configured. INFO: Found 52 targets and 0 test targets INFO: Found 41 targets and 11 test targets All tests passed but there were other errors during the build.
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This makes it very easy to get unit test coverage, but there's no simple way to get coverage data for tests that you run against the main version of your program, like end-to-end tests. Profilebut as of Go 1. We create a dummy test that executes mainwe put it behind a build tag, compile a binary with go test -c -cover and then run only that test instead of running the regular binary.
And then when we want to collect coverage information, we execute this instead of. You can still use command line arguments and standard input normally, just note that you will get two lines of extra output from the test framework.
Finally, since you probably also run unit tests, you might want to merge the coverage profiles with gocovmerge from issue :. If finding creative ways to test big-scale network services sounds fun, know that we are hiring in London, San Francisco and Singapore. Hi, I'm Filippo and today I managed to surprise myself! And not in a good way. Here at CloudFlare we are heavy users of the github. Therefore when Dmitry Vyukov published go-fuzz and started to uncover tens of bugs in the Go standard library, our task was clear Product News.
Cloudflare Network. Deep Dive. Life Cloudflare. Filippo Valsorda. Related Posts.Package testing provides support for automated testing of Go packages.Test Setup & Write your first test in Golang - Go Tests #1
The function name serves to identify the test routine. Put the file in the same package as the one being tested.
Benchmarks are run sequentially. The benchmark function must run the target code b. N times. During benchmark execution, b. N is adjusted until the benchmark function lasts long enough to be timed reliably.
The output. If a benchmark needs to test performance in a parallel setting, it may use the RunParallel helper function; such benchmarks are intended to be used with the go test -cpu flag:. The package also runs and verifies example code. Example functions may include a concluding line comment that begins with "Output:" and is compared with the standard output of the function when the tests are run. The comparison ignores leading and trailing space. These are examples of an example:. The comment prefix "Unordered output:" is like "Output:", but matches any line order:.
The naming convention to declare examples for the package, a function F, a type T and method M on type T are:. The suffix must start with a lower-case letter. The entire test file is presented as the example when it contains a single example function, at least one other function, type, variable, or constant declaration, and no test or benchmark functions. The Run methods of T and B allow defining subtests and sub-benchmarks, without having to define separate functions for each.
This enables uses like table-driven benchmarks and creating hierarchical tests. It also provides a way to share common setup and tear-down code:. Each subtest and sub-benchmark has a unique name: the combination of the name of the top-level test and the sequence of names passed to Run, separated by slashes, with an optional trailing sequence number for disambiguation.
The argument to the -run and -bench command-line flags is an unanchored regular expression that matches the test's name. For tests with multiple slash-separated elements, such as subtests, the argument is itself slash-separated, with expressions matching each name element in turn.
Because it is unanchored, an empty expression matches any string. For example, using "matching" to mean "whose name contains":. Subtests can also be used to control parallelism. A parent test will only complete once all of its subtests complete. In this example, all tests are run in parallel with each other, and only with each other, regardless of other top-level tests that may be defined:.From the beginning of the project, Go was designed with tools in mind.
Those tools include some of the most iconic pieces of Go technology such as the documentation presentation tool godocthe code formatting tool gofmtand the API rewriter gofix.
Perhaps most important of all is the go commandthe program that automatically installs, builds, and tests Go programs using nothing more than the source code as the build specification.
The release of Go 1. First, some background: What does it mean for a language to support good tooling? It means that the language makes it easy to write good tools and that its ecosystem supports the construction of tools of all flavors. There are a number of properties of Go that make it suitable for tooling. For starters, Go has a regular syntax that is easy to parse. The grammar aims to be free of special cases that require complex machinery to analyze. Where possible, Go uses lexical and syntactic constructs to make semantic properties easy to understand.
Examples include the use of upper-case letters to define exported names and the radically simplified scoping rules compared to other languages in the C tradition. Finally, the standard library comes with production-quality packages to lex and parse Go source code. They also include, more unusually, a production-quality package to pretty-print Go syntax trees.
These packages in combination form the core of the gofmt tool, but the pretty-printer is worth singling out. Because it can take an arbitrary Go syntax tree and output standard-format, human-readable, correct code, it creates the possibility to build tools that transform the parse tree and output modified but correct and easy-to-read code. One example is the gofix tool, which automates the rewriting of code to use new language features or updated libraries.
Gofix let us make fundamental changes to the language and libraries in the run-up to Go 1. Inside Google, we have used gofix to make sweeping changes in a huge code repository that would be almost unthinkable in the other languages we use. There's no need any more to support multiple versions of some API; we can use gofix to update the entire company in one operation.
It's not just these big tools that these packages enable, of course. They also make it easy to write more modest programs such as IDE plugins, for instance. All these items build on each other, making the Go environment more productive by automating many tasks.
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Test coverage is a term that describes how much of a package's code is exercised by running the package's tests. The program that provides test coverage in Go 1.
The usual way to compute test coverage is to instrument the binary. For instance, the GNU gcov program sets breakpoints at branches executed by the binary.
As each branch executes, the breakpoint is cleared and the target statements of the branch are marked as 'covered'. This approach is successful and widely used.
An early test coverage tool for Go even worked the same way. But it has problems. It is difficult to implement, as analysis of the execution of binaries is challenging. It also requires a reliable way of tying the execution trace back to the source code, which can also be difficult, as any user of a source-level debugger can attest.
Problems there include inaccurate debugging information and issues such as in-lined functions complicating the analysis.
Go coverage with external tests
Most important, this approach is very non-portable. It needs to be done afresh for every architecture, and to some extent for every operating system since debugging support varies greatly from system to system. It does work, though, and for instance if you are a user of gccgo, the gcov tool can give you test coverage information.
However If you're a user of gc, the more commonly used Go compiler suite, until Go 1. For the new test coverage tool for Go, we took a different approach that avoids dynamic debugging.Options can be passed to Bazel in different ways.
Toggle navigation. Navigation Version: master master 3. Option Syntax Options can be passed to Bazel in different ways. This is deprecated and will be removed, please prefer shutting down the server explicitly if you wish to avoid lingering servers.
This policy is useful for workloads that are non-interactive, but do not want to lower their nice value. If false, then Bazel does not perform a system call.
If unspecified, Bazel uses the first. Changing this option will not cause the server to restart. The anticipatory scheduler may only honor up to priority 4. If set to a negative value, then Bazel does not perform a system call. This flag has no effect on all other platforms but is supported to ensure rc files can be shared among them without changes. Possible values are: user- interactive, user-initiated, default, utility, and background.
Zero means that the server will never shutdown. Note: If you specify a different option from one to the next Bazel invocation for this value, you'll likely start up a new, additional Bazel server. Bazel starts exactly one server per specified output base. Typically there is one output base per workspace - however, with this option you may have multiple output bases per workspace and thereby run multiple builds for the same client on the same machine concurrently.
See ' bazel help shutdown' on how to shutdown a Bazel server. Linux only. Stick this flag in your bazelrc once and forget about it so that you get coredumps when you actually encounter a condition that triggers them.