Add cache clean command (#560)

* feat: Add cache clean

Add command `cache clean` to clean the cache files
depending on the loaction of the caching files
under different OS.

* feat: Add test for cache clean

Clean cache files with command `arduino-cli cache clean`.

* simplify test code

Co-authored-by: Massimiliano Pippi <[email protected]>

Author: howjmay

Diff for: cli/cache/cache.go

@@ -0,0 +1,37 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2020 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 cache
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+// NewCommand created a new `cache` command
+func NewCommand() *cobra.Command {
+	cacheCommand := &cobra.Command{
+		Use:   "cache",
+		Short: "Arduino cache commands.",
+		Long:  "Arduino cache commands.",
+		Example: "# Clean caches.\n" +
+			" " + os.Args[0] + " cache clean\n\n",
+	}
+
+	cacheCommand.AddCommand(initCleanCommand())
+
+	return cacheCommand
+}

Diff for: cli/cache/clean.go

@@ -0,0 +1,49 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2020 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 cache
+
+import (
+	"os"
+
+	"github.com/arduino/arduino-cli/cli/errorcodes"
+	"github.com/arduino/arduino-cli/cli/feedback"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+func initCleanCommand() *cobra.Command {
+	cleanCommand := &cobra.Command{
+		Use:     "clean",
+		Short:   "Clean arduino cache.",
+		Long:    "Clean the files i.e. `~/arduino15/staging` in Linux.",
+		Example: "  " + os.Args[0] + " cache clean",
+		Args:    cobra.NoArgs,
+		Run:     runCleanCommand,
+	}
+	return cleanCommand
+}
+
+func runCleanCommand(cmd *cobra.Command, args []string) {
+	logrus.Info("Executing `arduino cache clean`")
+
+	cachePath := viper.GetString("directories.Downloads")
+	err := os.RemoveAll(cachePath)
+	if err != nil {
+		feedback.Errorf("Error cleaning caches: %v", err)
+		os.Exit(errorcodes.ErrGeneric)
+	}
+}

Diff for: cli/cli.go

@@ -23,6 +23,7 @@ import (
 	"strings"
 
 	"github.com/arduino/arduino-cli/cli/board"
+	"github.com/arduino/arduino-cli/cli/cache"
 	"github.com/arduino/arduino-cli/cli/compile"
 	"github.com/arduino/arduino-cli/cli/config"
 	"github.com/arduino/arduino-cli/cli/core"
@@ -67,6 +68,7 @@ func init() {
 // this is here only for testing
 func createCliCommandTree(cmd *cobra.Command) {
 	cmd.AddCommand(board.NewCommand())
+	cmd.AddCommand(cache.NewCommand())
 	cmd.AddCommand(compile.NewCommand())
 	cmd.AddCommand(config.NewCommand())
 	cmd.AddCommand(core.NewCommand())

Diff for: test/test_cache.py

@@ -0,0 +1,33 @@
+# This file is part of arduino-cli.
+#
+# Copyright 2020 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].
+import os
+
+
+def test_cache_clean(run_command, data_dir):
+    """
+    Clean the cache under arduino caching file directory which is
+    "<Arduino configure file path>/staging"
+    """
+    result = run_command("cache clean")
+    assert result.ok
+
+    # Generate /staging directory
+    result = run_command("lib list")
+    assert result.ok
+
+    result = run_command("cache clean")
+    assert result.ok
+
+    assert not os.path.isdir(os.path.join(data_dir, "staging"))