Create infra for sharing directories between tests

Author: cmaglie

Diff for: go.mod

@@ -57,7 +57,10 @@ require (
 	gopkg.in/yaml.v2 v2.4.0
 )
 
-require go.bug.st/testifyjson v1.1.1
+require (
+	github.com/rogpeppe/go-internal v1.3.0
+	go.bug.st/testifyjson v1.1.1
+)
 
 require (
 	github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect

Diff for: go.sum

@@ -310,6 +310,7 @@ github.com/rifflock/lfshook v0.0.0-20180920164130-b9218ef580f5/go.mod h1:GEXHk5H
 github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
+github.com/rogpeppe/go-internal v1.3.0 h1:RR9dF3JtopPvtkroDZuVD7qquD0bnHlKSqaQhgwt8yk=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0RK8m9o+Q=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=

Diff for: internal/integrationtest/arduino-cli.go

@@ -100,7 +100,11 @@ func NewArduinoCliWithinEnvironment(env *Environment, config *ArduinoCLIConfig)
 		workingDir:    env.RootDir(),
 	}
 	if config.UseSharedStagingFolder {
-		cli.stagingDir = env.SharedDownloadsDir()
+		sharedDir := env.SharedDownloadsDir()
+		cli.stagingDir = sharedDir.Lock()
+		env.RegisterCleanUpCallback(func() {
+			sharedDir.Unlock()
+		})
 	}
 
 	cli.cliEnvVars = map[string]string{

Diff for: internal/integrationtest/environment.go

@@ -28,21 +28,14 @@ var ProjectName = "cli"
 // Environment is a test environment for the test suite.
 type Environment struct {
 	rootDir      *paths.Path
-	downloadsDir *paths.Path
+	downloadsDir *SharedDir
 	t            *testing.T
 	cleanUp      func()
 }
 
-// SharedDir returns the shared downloads directory.
-func SharedDir(t *testing.T, id string) *paths.Path {
-	downloadsDir := paths.TempDir().Join(ProjectName + "-" + id)
-	require.NoError(t, downloadsDir.MkdirAll())
-	return downloadsDir
-}
-
 // NewEnvironment creates a new test environment.
 func NewEnvironment(t *testing.T) *Environment {
-	downloadsDir := SharedDir(t, "downloads")
+	downloadsDir := NewSharedDir(t, "downloads")
 	rootDir, err := paths.MkTempDir("", ProjectName)
 	require.NoError(t, err)
 	return &Environment{
@@ -75,7 +68,7 @@ func (e *Environment) RootDir() *paths.Path {
 }
 
 // SharedDownloadsDir return the shared directory for downloads
-func (e *Environment) SharedDownloadsDir() *paths.Path {
+func (e *Environment) SharedDownloadsDir() *SharedDir {
 	return e.downloadsDir
 }
 

Diff for: internal/integrationtest/shared_directory.go

@@ -0,0 +1,67 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2022 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 [email protected].
+
+package integrationtest
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/arduino/go-paths-helper"
+	"github.com/rogpeppe/go-internal/lockedfile"
+	"github.com/stretchr/testify/require"
+)
+
+// SharedDir is a directory that is shared between multiple tests.
+type SharedDir struct {
+	dir      *paths.Path
+	t        *testing.T
+	mux      sync.Mutex
+	fileLock *lockedfile.File
+}
+
+// Lock locks the shared directory for exclusive access and return the path to the directory.
+func (d *SharedDir) Lock() *paths.Path {
+	d.mux.Lock()
+	defer d.mux.Unlock()
+	if d.fileLock != nil {
+		panic("SharedDir already locked")
+	}
+	fileLock, err := lockedfile.Create(d.dir.Join(".lock").String())
+	require.NoError(d.t, err)
+	d.fileLock = fileLock
+	return d.dir
+}
+
+// Unlock unlocks the shared directory.
+func (d *SharedDir) Unlock() {
+	d.mux.Lock()
+	defer d.mux.Unlock()
+	if d.fileLock == nil {
+		panic("SharedDir already unlocked")
+	}
+	require.NoError(d.t, d.fileLock.Close())
+	d.fileLock = nil
+}
+
+// NewSharedDir creates a new shared directory.
+func NewSharedDir(t *testing.T, id string) *SharedDir {
+	dir := paths.TempDir().Join(ProjectName + "-" + id)
+	require.NoError(t, dir.MkdirAll())
+	return &SharedDir{
+		dir: dir,
+		t:   t,
+	}
+}