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goc is a comprehensive coverage testing system for The Go Programming Language, especially for some complex scenarios, like system testing code coverage collection and accurate testing.

Enjoy, Have Fun! Demo


# Mac/AMD64
curl -s | grep "browser_download_url.*-darwin-amd64.tar.gz" | cut -d : -f 2,3 | tr -d \" | xargs -n 1 curl -L | tar -zx && chmod +x goc && mv goc /usr/local/bin

# Linux/AMD64
curl -s | grep "browser_download_url.*-linux-amd64.tar.gz" | cut -d : -f 2,3 | tr -d \" | xargs -n 1 curl -L | tar -zx && chmod +x goc && mv goc /usr/local/bin

# Linux/386
curl -s | grep "browser_download_url.*-linux-386.tar.gz" | cut -d : -f 2,3 | tr -d \" | xargs -n 1 curl -L | tar -zx && chmod +x goc && mv goc /usr/local/bin

Goc supports both GOPATH project and Go Modules project with Go 1.11+. However, for developing goc, you need to install Go 1.13+.


You can use goc tool in many scenarios.

Code Coverage Collection for Your Golang System Tests

Goc can collect code coverages at runtime for your long-run golang applications. To do that, normally just need three steps:

  1. use goc server to start a service registry center:
    ➜  simple-go-server git:(master) ✗ goc server
  2. use goc build to build the target service, and run the generated binary. Here let's take the simple-go-server project as example:
    ➜  simple-go-server git:(master) ✗ goc build .
    ... // omit logs
    ➜  simple-go-server git:(master) ✗ ./simple-go-server  
  3. use goc profile to get the code coverage profile of the started simple server above:
    ➜  simple-go-server git:(master) ✗ goc profile
    mode: atomic
    enricofoltran/simple-go-server/main.go:30.13,48.33 13 1
    enricofoltran/simple-go-server/main.go:48.33,50.3 1 0
    enricofoltran/simple-go-server/main.go:52.2,65.12 5 1
    enricofoltran/simple-go-server/main.go:65.12,74.46 7 1
    enricofoltran/simple-go-server/main.go:74.46,76.4 1 0
    enricofoltran/simple-go-server/main.go:30.13,48.33 13 1
    File: enricofoltran/simple-go-server/main.go
    Position of first point of this code block: 30.13
    Position of second point of this code block: 48.33
    Number of statements of this code block: 13
    Number of executions of this code block: 1

Show Code Coverage Change at Runtime in Vscode

We provide a vscode extension - Goc Coverage which can show highlighted covered source code at runtime.



  1. To understand the execution details of goc tool, you can use the --debug flag. Also we appreciate if you can provide such logs when submitting a bug to us.

  2. By default, the covered service will listen a random port in order to communicate with the goc server. This may not be suitable in docker or kubernetes environment since the port must be exposed explicitly in order to be accessible by others in such environment. For this kind of scenario, you can use --agentport flag to specify a fixed port when calling goc build or goc install.

  3. To use a remote goc server, you can use --center flag to compile the target service with goc build or goc install command.

  4. The coverage data is stored on each covered service side, so if one service needs to restart during test, this service's coverage data will be lost. For this case, you can use following steps to handle:

    1. Before the service restarts, collect coverage with goc profile -o a.cov
    2. After service restarted and test finished, collect coverage again with goc profile -o b.cov
    3. Merge two coverage profiles together: goc merge a.cov b.cov -o merge.cov
  5. By default, goc will use the artifact's file name as its service name. You can overwrite it by setting environment variable GOC_SERVICE_NAME. (See #293 for details)


  • Support code coverage collection for system testing.
  • Support code coverage counters clear for the services under test at runtime.
  • Support develop mode towards accurate testing.
  • Support code coverage diff based on Pull Request.
  • Optimize the performance costed by code coverage counters.


We welcome all kinds of contribution, including bug reports, feature requests, documentation improvements, UI refinements, etc.

Thanks to all contributors!!


Goc is released under the Apache 2.0 license. See LICENSE.txt