Description

The Store method in pkg/testcoverage/badgestorer/github.go has a nil pointer dereference on line 64 when building with Go 1.25:

fc, _, httpResp, err := client.Repositories.GetContents(...)
if httpResp.StatusCode == http.StatusNotFound { // <-- BUG: httpResp can be nil when err != nil
    return updateBadge(nil)
}

When the GitHub API call fails (e.g., invalid token), httpResp is nil, and accessing .StatusCode before checking err causes a panic.

Go 1.25 Behavior Change

Go 1.25 fixed a spec violation where the compiler sometimes delayed nil pointer checks. This masked the bug in earlier Go versions. See: https://go.dev/doc/go1.25#nil-checks

How to Reproduce

# Build with Go 1.25 and run tests
go test ./pkg/testcoverage/badgestorer/...

The Test_Github_Error test triggers this because it uses an invalid token (🔑), causing the API call to fail.

Stack Trace

--- FAIL: Test_Github_Error (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered, repanicked]
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x8ceba5]

github.com/vladopajic/go-test-coverage/v2/pkg/testcoverage/badgestorer.(*githubStorer).Store(0xc000071f10, {0xc000014270, 0xa, 0xa})
    /build/source/pkg/testcoverage/badgestorer/github.go:64 +0x1a5

Suggested Fix

Check err before accessing httpResp:

fc, _, httpResp, err := client.Repositories.GetContents(...)
if err != nil {
    // Check for 404 via error type, or return error
    var ghErr *github.ErrorResponse
    if errors.As(err, &ghErr) && ghErr.Response != nil && ghErr.Response.StatusCode == http.StatusNotFound {
        return updateBadge(nil)
    }
    return false, fmt.Errorf("get badge content: %w", err)
}

// Now safe to access httpResp
if httpResp != nil && httpResp.StatusCode == http.StatusNotFound {
    return updateBadge(nil)
}

Environment

• Go version: 1.25.5
• go-test-coverage version: v2.18.3
• OS: Linux (GitHub Actions / Nix)