Fix platform tool dependency determination (#1020)

* Fix platform tool dependency determination

The platform tool dependency check was giving false negatives due to comparing pointers instead of version values.

This caused tools to be removed during platform uninstallation even when another installed platform had a dependency on
that tool.

* Add integration test for tool removal during platform uninstall

Tool dependency by `arduino-cli core uninstall` is somewhat complex because it must only uninstall the tools that no
other platforms have a dependency on. If it doesn't, it breaks the other platform and the cause of this breakage would
likely not be obvious to the user.

So it's important to test to ensure this functionality continues to work correctly.

Author: per1234

Diff for: arduino/cores/cores.go

@@ -218,7 +218,7 @@ func (release *PlatformRelease) RequiresToolRelease(toolRelease *ToolRelease) bo
 	for _, toolDep := range release.Dependencies {
 		if toolDep.ToolName == toolRelease.Tool.Name &&
 			toolDep.ToolPackager == toolRelease.Tool.Package.Name &&
-			toolDep.ToolVersion == toolRelease.Version {
+			toolDep.ToolVersion.Equal(toolRelease.Version) {
 			return true
 		}
 	}

Diff for: arduino/cores/cores_test.go

@@ -0,0 +1,57 @@
+// 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 cores
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	semver "go.bug.st/relaxed-semver"
+)
+
+func TestRequiresToolRelease(t *testing.T) {
+	toolDependencyName := "avr-gcc"
+	toolDependencyVersion := "7.3.0-atmel3.6.1-arduino7"
+	toolDependencyPackager := "arduino"
+
+	release := PlatformRelease{
+		Dependencies: ToolDependencies{
+			{
+				ToolName:     toolDependencyName,
+				ToolVersion:  semver.ParseRelaxed(toolDependencyVersion),
+				ToolPackager: toolDependencyPackager,
+			},
+		},
+	}
+
+	toolRelease := &ToolRelease{
+		Version: semver.ParseRelaxed(toolDependencyVersion + "not"),
+		Tool: &Tool{
+			Name: toolDependencyName + "not",
+			Package: &Package{
+				Name: toolDependencyPackager + "not",
+			},
+		},
+	}
+
+	require.False(t, release.RequiresToolRelease(toolRelease))
+	toolRelease.Tool.Name = toolDependencyName
+	require.False(t, release.RequiresToolRelease(toolRelease))
+	toolRelease.Tool.Package.Name = toolDependencyPackager
+	require.False(t, release.RequiresToolRelease(toolRelease))
+	toolRelease.Version = semver.ParseRelaxed(toolDependencyVersion)
+	require.True(t, release.RequiresToolRelease(toolRelease))
+}

Diff for: test/test_core.py

@@ -236,6 +236,27 @@ def test_core_uninstall(run_command):
     assert not _in(result.stdout, "arduino:avr")
 
 
+def test_core_uninstall_tool_dependency_removal(run_command, data_dir):
+    # These platforms both have a dependency on the arduino:[email protected] tool
+    # arduino:[email protected] has a dependency on arduino:[email protected]
+    assert run_command("core install arduino:[email protected]")
+    # arduino:[email protected] has a dependency on arduino:[email protected]
+    assert run_command("core install arduino:[email protected]")
+    assert run_command("core uninstall arduino:avr")
+
+    arduino_tools_path = Path(data_dir, "packages", "arduino", "tools")
+
+    avr_gcc_binaries_path = arduino_tools_path.joinpath("avr-gcc", "7.3.0-atmel3.6.1-arduino5", "bin")
+    # The tool arduino:[email protected] that is a dep of another installed platform should remain
+    assert avr_gcc_binaries_path.joinpath("avr-gcc").exists() or avr_gcc_binaries_path.joinpath("avr-gcc.exe").exists()
+
+    avrdude_binaries_path = arduino_tools_path.joinpath("avrdude", "6.3.0-arduino17", "bin")
+    # The tool arduino:[email protected] that is only a dep of arduino:avr should have been removed
+    assert (
+        avrdude_binaries_path.joinpath("avrdude").exists() or avrdude_binaries_path.joinpath("avrdude.exe").exists()
+    ) is False
+
+
 def test_core_zipslip(run_command):
     url = "https://raw.githubusercontent.com/arduino/arduino-cli/master/test/testdata/test_index.json"
     assert run_command("core update-index --additional-urls={}".format(url))