[skip-changelog] Added process.RunWithinContext method (#1546)

This method allows to bound process execution to a context.

Author: cmaglie

executils/process.go

@@ -16,6 +16,7 @@
 package executils
 
 import (
+	"context"
 	"io"
 	"os"
 	"os/exec"
@@ -141,3 +142,19 @@ func (p *Process) Run() error {
 func (p *Process) SetEnvironment(values []string) {
 	p.cmd.Env = values
 }
+
+// RunWithinContext starts the specified command and waits for it to complete. If the given context
+// is canceled before the normal process termination, the process is killed.
+func (p *Process) RunWithinContext(ctx context.Context) error {
+	completed := make(chan struct{})
+	defer close(completed)
+	go func() {
+		select {
+		case <-ctx.Done():
+			p.Kill()
+		case <-completed:
+		}
+	}()
+	res := p.cmd.Run()
+	return res
+}

executils/process_test.go

@@ -0,0 +1,42 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2021 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to license@arduino.cc.
+
+package executils
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestProcessWithinContext(t *testing.T) {
+	// Build `delay` helper inside testdata/delay
+	builder, err := NewProcess("go", "build")
+	require.NoError(t, err)
+	builder.SetDir("testdata/delay")
+	require.NoError(t, builder.Run())
+
+	// Run delay and test if the process is terminated correctly due to context
+	process, err := NewProcess("testdata/delay/delay")
+	require.NoError(t, err)
+	start := time.Now()
+	ctx, cancel := context.WithTimeout(context.Background(), 250*time.Millisecond)
+	err = process.RunWithinContext(ctx)
+	require.Error(t, err)
+	require.Less(t, time.Since(start), 500*time.Millisecond)
+	cancel()
+}

executils/testdata/delay/.gitignore

@@ -0,0 +1 @@
+delay*

executils/testdata/delay/main.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func main() {
+	time.Sleep(3 * time.Second)
+	fmt.Println("Elapsed!")
+}