Incorrect visualization of code coverage report for Golang

[georgethebeatle]

Hello there,

My team has set up code coverage reporting for our project. It is a golang project and we are generating cover.out files in the gocov format. We noticed some weird looking files in our report

I am also attaching a screenshot of the relevant section in case the report is changed by future builds:

There are a couple of things to be noted there:

• line 39 looks like it is not a statement, while actially it is
• line 47 is reported as covered, but line 48 is reported as not covered, which is impossible, because they are two adjacent lines in the same conditional statement - they should either be both covered or both not covered
• line 43 and line 50 both consist of a closing brace ({). Line 50 is displayed as a statement that is not covered, while line 43 is displayed as a non-statement, which is inconsistent.

We took a look at our raw cover.out file, which is in gocov format and it looks fine to us. Here is a screenshot of the same section of the code as displayed by the html report generated by go tool cover -html=cover.out:

As you can see none of the above mentioned anomalies are present, meaning that the cover.out file is generated correctly.

We went a bit further and converted the raw file to the codeclimate format using the latest test reporter. Here is the relevant section of the json file:

    {
      "blob_id": "89e3dca239b3cb84a3a439033582a5c5782dcddd",
      "coverage": "[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,3,null,null,null,null,null,null,3,3,3,3,3,null,null,1,1,1,null,null,null,3,3,0,0,0,null,null,3,3,null,null,3,3,3,null,null,1,null,null,3]",
      "covered_percent": 85.71428571428571,
      "covered_strength": 2.1904761904761907,
      "line_counts": {
        "missed": 3,
        "covered": 18,
        "total": 21
      },
      "name": "api/apis/job_handler.go"
    },

We interpreted the coverage key of that json a a bitmap, each element corresponding to a line, where null is not a statement and a number means that the line is a statement and represents how many times the statement is visited. This interpretation aligned perfectly with the first screenshot above and confirmed our suspicion that the test reporter is not formatting the cover.out correctly.

Here is the full cover.out file for more detailed information:
cover.out.txt

[georgethebeatle]

We opened a PR that fixes this issue

[f-moya]

@georgethebeatle will be looking at this next week 👍🏼

[georgethebeatle]

This issue has been addressed by PR #480, closing.