...
	$

4. Convert coverage data to legacy textual format:

	$ go tool covdata textfmt -i=profiledir -o=cov.txt
	$ head cov.txt
	mode: set
	cov-example/p/p.go:12.22,13.2 0 0
	cov-example/p/p.go:15.31,16.2 1 0
	cov-example/p/p.go:16.3,18.3 0 0
	cov-example/p/p.go:19.3,21.3 0 0
	...
	$ go tool cover -html=cov.txt
	$

5. Merge profiles together:

// source code to 0.
func ResetCoverage() {
	cov := coverage()
	clear(cov)
}

// SnapshotCoverage copies the current counter values into coverageSnapshot,
// preserving them for later inspection. SnapshotCoverage also rounds each
// counter down to the nearest power of two. This lets the coordinator store
// multiple values for each counter by OR'ing them together.
func SnapshotCoverage() {
	cov := coverage()
	for i, b := range cov {

	// ... off and running now.
	dbgtrace(1, "starting perform")

	indirs := strings.Split(*indirsflag, ",")
	vis := cov.CovDataVisitor(op)
	var flags cov.CovDataReaderFlags
	if *hflag {
		flags |= cov.PanicOnError
	}
	if *hwflag {
		flags |= cov.PanicOnWarning
	}
	reader := cov.MakeCovDataReader(vis, indirs, *verbflag, flags, matchpkg)
	st := 0
	if err := reader.Visit(); err != nil {

! stderr 'compile(\.exe"?)? -'
! stderr 'cover(\.exe"?)? -'
[GOEXPERIMENT:coverageredesign] stderr 'covdata(\.exe"?)? percent'

# Now add in -coverprofile.
go test -cover -coverprofile=cov.dat ./pkg1 ./pkg2 ./pkg3 ./pkg4
[!GOEXPERIMENT:coverageredesign] stdout 'pkg1	\[no test files\]'
[GOEXPERIMENT:coverageredesign] stdout 'pkg1		coverage: 0.0% of statements'

# packages); prior to the fix for #58770 Go 1.20 would show 100%
# coverage. For packages "x" and "f" (which have no tests), check for
# 0% stmts covered (as opposed to "no test files").

go test -count=1 -coverprofile=cov.dat -coverpkg=./... ./...
stdout '^\s*\?\s+M/n\s+\[no test files\]'
stdout '^\s*M/x\s+coverage: 0.0% of statements'
stdout '^\s*M/f\s+coverage: 0.0% of statements'
stdout '^ok\s+M/a\s+\S+\s+coverage: 30.0% of statements in ./...'

# multiple packages without tests.

[short] skip

# Kick off test.
go test -p=10 -vet=off -count=1 -coverprofile=cov.p ./...

# Make sure resulting profile is digestible.
go tool cover -func=cov.p

# No extraneous extra files please.
! exists _cover_.out

-- a/a.go --
package a

func init() {
	println("package 'a' init: launch the missiles!")
}

// Copyright 2022 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main_test

import (
	"cmd/internal/cov/covcmd"
	"encoding/json"
	"fmt"
	"internal/testenv"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func writeFile(t *testing.T, path string, contents []byte) {
	if err := os.WriteFile(path, contents, 0666); err != nil {

# f               yes             no              3               ---
#

[short] skip
[!GOEXPERIMENT:coverageredesign] skip

# Test all packages with -coverpkg=./...
go test -coverprofile=cov.p -coverpkg=./... ./...
stdout '^ok\s+M/a\s+\S+\s+coverage: 50.0% of statements in ./...'
stdout '^ok\s+M/b\s+\S+\s+coverage: 60.0% of statements in ./...'
stdout '^ok\s+M/c\s+\S+\s+coverage: 30.0% of statements in ./...'

	pkgs := make([]string, 0, len(fm.pm))
	for importpath := range fm.pm {
		pkgs = append(pkgs, importpath)
	}

	rep := func(cov, tot uint64) error {
		if tot != 0 {
			if _, err := fmt.Fprintf(w, "coverage: %.1f%% of statements%s\n",
				100.0*float64(cov)/float64(tot), covpkgs); err != nil {
				return err
			}
		} else if noteEmpty {

```console
$ pytest

================ test session starts ================
platform linux -- Python 3.6.9, pytest-5.3.5, py-1.8.1, pluggy-0.13.1
rootdir: /home/user/code/superawesome-cli/app
plugins: forked-1.1.3, xdist-1.31.0, cov-2.8.1
collected 6 items

---> 100%

test_main.py <span style="color: green; white-space: pre;">......                            [100%]</span>