cleanup: move legacy from internal/engine to internal (#759)

No functional change.

See https://github.com/ooni/probe/issues/2115

internal/engine/legacy/README.md

@@ -1,4 +0,0 @@
-# Package github.com/ooni/probe-engine/legacy
-
-This package contains legacy code that we will soon remove. When this folder
-is empty, it means there's no large, incremental refactoring in progress.

internal/engine/legacy/assetsdir/assetsdir.go

@@ -1,62 +0,0 @@
-// Package assetsdir contains code to cleanup the assets dir. We removed
-// the assetsdir in the 3.9.0 development cycle.
-package assetsdir
-
-import (
-	"errors"
-	"os"
-	"path/filepath"
-)
-
-// ErrEmptyDir indicates that you passed to Cleanup an empty dir.
-var ErrEmptyDir = errors.New("empty assets directory")
-
-// Result is the result of a Cleanup run.
-type Result struct {
-	// ASNDatabaseErr is the error of deleting the
-	// file containing the old ASN database.
-	ASNDatabaseErr error
-
-	// CABundleErr is the error of deleting the file
-	// containing the old CA bundle.
-	CABundleErr error
-
-	// CountryDatabaseErr is the error of deleting the
-	// file containing the old country database.
-	CountryDatabaseErr error
-
-	// RmdirErr is the error of deleting the supposedly
-	// empty directory that contained assets.
-	RmdirErr error
-}
-
-// Cleanup removes data from the assetsdir. This function will
-// try to delete the known assets inside of dir. It then also
-// tries to delete the directory. If the directory is not empty,
-// this operation will fail. That means the user has put some
-// extra data in there and we don't want to remove it.
-//
-// Returns the Result of cleaning up the assets on success and
-// an error on failure. The only cause of error is passing to
-// this function an empty directory. The Result data structure
-// contains the result of each individual remove operation.
-func Cleanup(dir string) (*Result, error) {
-	return fcleanup(dir, os.Remove)
-}
-
-// fcleanup is a version of Cleanup where we can mock the real function
-// used for removing files and dirs, so we can write unit tests.
-func fcleanup(dir string, remove func(name string) error) (*Result, error) {
-	if dir == "" {
-		return nil, ErrEmptyDir
-	}
-	r := &Result{}
-	asndb := filepath.Join(dir, "asn.mmdb")
-	r.ASNDatabaseErr = os.Remove(asndb)
-	cabundle := filepath.Join(dir, "ca-bundle.pem")
-	r.CABundleErr = os.Remove(cabundle)
-	countrydb := filepath.Join(dir, "country.mmdb")
-	r.CountryDatabaseErr = os.Remove(countrydb)
-	r.RmdirErr = os.Remove(dir)
-	return r, nil
-}

internal/engine/legacy/assetsdir/assetsdir_test.go

@@ -1,40 +0,0 @@
-package assetsdir
-
-import (
-	"errors"
-	"strings"
-	"testing"
-)
-
-func TestCleanupNormalUsage(t *testing.T) {
-	result, err := Cleanup("testdata")
-	if err != nil {
-		t.Fatal(err)
-	}
-	// we expect a bunch of ENOENT because the directory does not exist.
-	isExpectedErr := func(err error) bool {
-		return err != nil && strings.HasSuffix(err.Error(), "no such file or directory")
-	}
-	if !isExpectedErr(result.ASNDatabaseErr) {
-		t.Fatal("unexpected error", result.ASNDatabaseErr)
-	}
-	if !isExpectedErr(result.CABundleErr) {
-		t.Fatal("unexpected error", result.CABundleErr)
-	}
-	if !isExpectedErr(result.CountryDatabaseErr) {
-		t.Fatal("unexpected error", result.CountryDatabaseErr)
-	}
-	if !isExpectedErr(result.RmdirErr) {
-		t.Fatal("unexpected error", result.RmdirErr)
-	}
-}
-
-func TestCleanupWithEmptyInput(t *testing.T) {
-	result, err := Cleanup("")
-	if !errors.Is(err, ErrEmptyDir) {
-		t.Fatal("unexpected error", err)
-	}
-	if result != nil {
-		t.Fatal("expected nil result")
-	}
-}