databricks-cli/internal/helpers.go

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package internal
import (
"bufio"
"bytes"
"context"
"fmt"
"math/rand"
"os"
"path/filepath"
"strings"
"testing"
"time"
"github.com/databricks/cli/cmd/root"
"github.com/stretchr/testify/require"
)
const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
// GetEnvOrSkipTest proceeds with test only with that env variable
func GetEnvOrSkipTest(t *testing.T, name string) string {
value := os.Getenv(name)
if value == "" {
t.Skipf("Environment variable %s is missing", name)
}
return value
}
// RandomName gives random name with optional prefix. e.g. qa.RandomName("tf-")
func RandomName(prefix ...string) string {
rand.Seed(time.Now().UnixNano())
randLen := 12
b := make([]byte, randLen)
for i := range b {
b[i] = charset[rand.Intn(randLen)]
}
if len(prefix) > 0 {
return fmt.Sprintf("%s%s", strings.Join(prefix, ""), b)
}
return string(b)
}
// Helper for running the root command in the background.
// It ensures that the background goroutine terminates upon
// test completion through cancelling the command context.
type cobraTestRunner struct {
*testing.T
args []string
stdout bytes.Buffer
stderr bytes.Buffer
errch <-chan error
}
func (t *cobraTestRunner) RunBackground() {
root := root.RootCmd
root.SetOut(&t.stdout)
root.SetErr(&t.stderr)
root.SetArgs(t.args)
errch := make(chan error)
ctx, cancel := context.WithCancel(context.Background())
// Run command in background.
go func() {
cmd, err := root.ExecuteContextC(ctx)
if err != nil {
t.Logf("Error running command: %s", err)
}
if t.stdout.Len() > 0 {
// Make a copy of the buffer such that it remains "unread".
scanner := bufio.NewScanner(bytes.NewBuffer(t.stdout.Bytes()))
for scanner.Scan() {
t.Logf("[databricks stdout]: %s", scanner.Text())
}
}
if t.stderr.Len() > 0 {
// Make a copy of the buffer such that it remains "unread".
scanner := bufio.NewScanner(bytes.NewBuffer(t.stderr.Bytes()))
for scanner.Scan() {
t.Logf("[databricks stderr]: %s", scanner.Text())
}
}
// Reset context on command for the next test.
// These commands are globals so we have to clean up to the best of our ability after each run.
// See https://github.com/spf13/cobra/blob/a6f198b635c4b18fff81930c40d464904e55b161/command.go#L1062-L1066
//lint:ignore SA1012 cobra sets the context and doesn't clear it
cmd.SetContext(nil)
// Make caller aware of error.
errch <- err
close(errch)
}()
// Ensure command terminates upon test completion (success or failure).
t.Cleanup(func() {
// Signal termination of command.
cancel()
// Wait for goroutine to finish.
<-errch
})
t.errch = errch
}
func (t *cobraTestRunner) Run() (bytes.Buffer, bytes.Buffer, error) {
t.RunBackground()
err := <-t.errch
return t.stdout, t.stderr, err
}
// Like [require.Eventually] but errors if the underlying command has failed.
func (c *cobraTestRunner) Eventually(condition func() bool, waitFor time.Duration, tick time.Duration, msgAndArgs ...interface{}) {
ch := make(chan bool, 1)
timer := time.NewTimer(waitFor)
defer timer.Stop()
ticker := time.NewTicker(tick)
defer ticker.Stop()
for tick := ticker.C; ; {
select {
case err := <-c.errch:
require.Fail(c, "Command failed", err)
return
case <-timer.C:
require.Fail(c, "Condition never satisfied", msgAndArgs...)
return
case <-tick:
tick = nil
go func() { ch <- condition() }()
case v := <-ch:
if v {
return
}
tick = ticker.C
}
}
}
func NewCobraTestRunner(t *testing.T, args ...string) *cobraTestRunner {
return &cobraTestRunner{
T: t,
args: args,
}
}
2022-12-09 14:41:04 +00:00
func RequireSuccessfulRun(t *testing.T, args ...string) (bytes.Buffer, bytes.Buffer) {
c := NewCobraTestRunner(t, args...)
stdout, stderr, err := c.Run()
require.NoError(t, err)
return stdout, stderr
}
func writeFile(t *testing.T, name string, body string) string {
f, err := os.Create(filepath.Join(t.TempDir(), name))
require.NoError(t, err)
_, err = f.WriteString(body)
require.NoError(t, err)
f.Close()
return f.Name()
}