Add Move command

This tries to replicate the mv command using mostly the same logic from
the existing shx.Copy command.

Signed-off-by: Carolyn Van Slyck <me@carolynvanslyck.com>

magefile.go

@@ -1,3 +1,4 @@
+//go:build mage
 // +build mage
 
 package main

shx/copy.go

@@ -10,8 +10,8 @@ import (
 type CopyOption int
 
 const (
-	// CopyNoOverwrite does not overwrite existing files in the destination
 	CopyDefault CopyOption = iota
+	// CopyNoOverwrite does not overwrite existing files in the destination
 	CopyNoOverwrite
 	CopyRecursive
 )

shx/copy_test.go

@@ -183,6 +183,8 @@ func TestCopy_CopyNoOverwrite(t *testing.T) {
 }
 
 func assertFile(t *testing.T, f string) {
+	t.Helper()
+
 	gotContents, err := ioutil.ReadFile(f)
 	require.NoErrorf(t, err, "could not read file %s", f)
 

shx/move.go

@@ -0,0 +1,97 @@
+package shx
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+type MoveOption int
+
+const (
+	MoveDefault MoveOption = iota
+	// MoveNoOverwrite does not overwrite existing files in the destination
+	MoveNoOverwrite
+	MoveRecursive
+)
+
+// Move a file or directory with the specified set of MoveOption.
+// The source may use globbing, which is resolved with filepath.Glob.
+func Move(src string, dest string, opts ...MoveOption) error {
+	items, err := filepath.Glob(src)
+	if err != nil {
+		return err
+	}
+
+	if len(items) == 0 {
+		return fmt.Errorf("no such file or directory '%s'", src)
+	}
+
+	var combinedOpts MoveOption
+	for _, opt := range opts {
+		combinedOpts |= opt
+	}
+
+	// Check if the destination exists, e.g. if we are moving to /tmp/foo, /tmp should already exist
+	if _, err := os.Stat(filepath.Dir(dest)); err != nil {
+		return err
+	}
+
+	for _, item := range items {
+		err := moveFileOrDirectory(item, dest, combinedOpts)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func moveFileOrDirectory(src string, dest string, opts MoveOption) error {
+	// If the destination is a directory that exists,
+	// move into the directory.
+	destInfo, err := os.Stat(dest)
+	if err == nil && destInfo.IsDir() {
+		dest = filepath.Join(dest, filepath.Base(src))
+	}
+
+	return move(src, dest, opts)
+}
+
+func move(src string, dest string, opts MoveOption) error {
+	destExists := true
+	destInfo, err := os.Stat(dest)
+	if err != nil {
+		if os.IsNotExist(err) {
+			destExists = false
+		} else {
+			return err
+		}
+	}
+
+	overwrite := opts&MoveNoOverwrite != MoveNoOverwrite
+	if destExists {
+		if overwrite {
+			// Do not try to rename a file to an existing directory (mimics mv behavior)
+			if destInfo.IsDir() {
+				srcInfo, err := os.Stat(src)
+				if err != nil {
+					return err
+				}
+				if !srcInfo.IsDir() {
+					return fmt.Errorf("rename %s to %s: not a directory", src, dest)
+				}
+			}
+
+			os.RemoveAll(dest)
+		} else {
+			// Do not overwrite, skip
+			log.Printf("%s not overwritten\n", dest)
+			return nil
+		}
+	}
+
+	log.Printf("%s -> %s\n", src, dest)
+	return os.Rename(src, dest)
+}

shx/move_example_test.go

@@ -0,0 +1,18 @@
+package shx_test
+
+import "github.com/carolynvs/magex/shx"
+
+func ExampleMove() {
+	// Move a file from the current directory into TEMP
+	shx.Move("a.txt", "/tmp")
+
+	// Move matching files in the current directory into TEMP
+	shx.Move("*.txt", "/tmp")
+
+	// Overwrite a file
+	shx.Move("/tmp/a.txt", "/tmp/b.txt")
+
+	// Move the contents of a directory into TEMP
+	// Do not overwrite existing files
+	shx.Move("a/*", "/tmp", shx.MoveNoOverwrite)
+}

shx/move_test.go

@@ -0,0 +1,205 @@
+package shx
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func resetTestdata(t *testing.T) {
+	err := exec.Command("git", "checkout", "testdata").Run()
+	require.NoError(t, err, "error resetting the testdata directory")
+}
+
+func TestMove(t *testing.T) {
+	t.Run("recursively move directory into empty dest dir", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("testdata", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		err = Move("testdata/copy/a", tmp, MoveRecursive)
+		require.NoError(t, err, "Move into empty directory failed")
+
+		assert.DirExists(t, filepath.Join(tmp, "a"))
+		assertFile(t, filepath.Join(tmp, "a/a1.txt"))
+		assertFile(t, filepath.Join(tmp, "a/a2.txt"))
+		assert.DirExists(t, filepath.Join(tmp, "a/ab"))
+		assertFile(t, filepath.Join(tmp, "a/ab/ab1.txt"))
+		assertFile(t, filepath.Join(tmp, "a/ab/ab2.txt"))
+	})
+
+	t.Run("recursively move directory into populated dest dir", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		require.NoError(t, os.MkdirAll(filepath.Join(tmp, "a"), 0700))
+		require.NoError(t, os.WriteFile(filepath.Join(tmp, "a/a1.txt"), []byte("a lot of extra data that should be overwritten"), 0600))
+
+		err = Move("testdata/copy/a", tmp, MoveRecursive)
+		require.NoError(t, err, "Move into directory with same directory name")
+
+		assert.DirExists(t, filepath.Join(tmp, "a"))
+		assertFile(t, filepath.Join(tmp, "a/a1.txt"))
+		assertFile(t, filepath.Join(tmp, "a/a2.txt"))
+		assert.DirExists(t, filepath.Join(tmp, "a/ab"))
+		assertFile(t, filepath.Join(tmp, "a/ab/ab1.txt"))
+		assertFile(t, filepath.Join(tmp, "a/ab/ab2.txt"))
+	})
+
+	t.Run("move glob", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		err = Move("testdata/copy/a/*.txt", tmp)
+		require.NoError(t, err, "Move into empty directory failed")
+
+		assertFile(t, filepath.Join(tmp, "a1.txt"))
+		assertFile(t, filepath.Join(tmp, "a2.txt"))
+		assert.NoDirExists(t, filepath.Join(tmp, "a"))
+		assert.NoDirExists(t, filepath.Join(tmp, "ab"))
+	})
+
+	t.Run("missing parent dir", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		err = Move("testdata/copy/a", filepath.Join(tmp, "missing-parent/dir"))
+		require.Error(t, err)
+	})
+
+	t.Run("missing src", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		err = Move("testdata/missing-src", tmp)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "no such file or directory")
+	})
+
+	t.Run("recursively move directory to new name", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		dest := filepath.Join(tmp, "dest")
+		err = Move("testdata/copy/a", dest, MoveRecursive)
+		require.NoError(t, err, "Move into empty directory failed")
+
+		assert.DirExists(t, dest)
+		assertFile(t, filepath.Join(dest, "a1.txt"))
+		assertFile(t, filepath.Join(dest, "a2.txt"))
+		assert.DirExists(t, filepath.Join(dest, "ab"))
+		assertFile(t, filepath.Join(dest, "ab/ab1.txt"))
+		assertFile(t, filepath.Join(dest, "ab/ab2.txt"))
+	})
+
+	t.Run("recursively merge dest dir", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		err = Move("testdata/copy/partial-dest", tmp, MoveRecursive)
+		require.NoError(t, err, "Move partial destination failed")
+
+		err = Move("testdata/copy/a", tmp, MoveRecursive)
+		require.NoError(t, err, "Merge into non-empty destination failed")
+
+		assert.DirExists(t, filepath.Join(tmp, "a"))
+		assertFile(t, filepath.Join(tmp, "a/a1.txt"))
+		assertFile(t, filepath.Join(tmp, "a/a2.txt"))
+		assert.DirExists(t, filepath.Join(tmp, "a/ab"))
+		assertFile(t, filepath.Join(tmp, "a/ab/ab1.txt"))
+		assertFile(t, filepath.Join(tmp, "a/ab/ab2.txt"))
+	})
+
+	t.Run("move file into empty directory", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		err = Move("testdata/copy/a/a1.txt", tmp)
+		require.NoError(t, err, "Move file failed")
+
+		assertFile(t, filepath.Join(tmp, "a1.txt"))
+	})
+
+	t.Run("overwrite directory should fail", func(t *testing.T) {
+		defer resetTestdata(t)
+
+		// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+		tmp, err := ioutil.TempDir("", "magex")
+		require.NoError(t, err, "could not create temp directory for test")
+		defer os.RemoveAll(tmp)
+
+		err = Move("testdata/copy/directory-conflict/a", tmp, MoveRecursive)
+		require.NoError(t, err, "Setup failed")
+
+		err = Move("testdata/copy/a/*", filepath.Join(tmp, "a"))
+		require.Error(t, err, "Overwrite directory should have failed")
+	})
+}
+
+func TestMove_MoveNoOverwrite(t *testing.T) {
+	testcases := []struct {
+		name         string
+		opts         MoveOption
+		wantContents string
+	}{
+		{name: "overwrite", opts: MoveDefault, wantContents: "a2.txt"},
+		{name: "no overwrite", opts: MoveNoOverwrite, wantContents: "a1.txt"},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.name, func(t *testing.T) {
+			defer resetTestdata(t)
+
+			// Make the temp directory on the same physical drive, os.Rename doesn't work across drives and /tmp may be on another drive
+			tmp, err := ioutil.TempDir("", "magex")
+			require.NoError(t, err, "could not create temp directory for test")
+			defer os.RemoveAll(tmp)
+
+			err = Move("testdata/copy/a/a1.txt", tmp)
+			require.NoError(t, err, "Move a1.txt failed")
+
+			err = Move("testdata/copy/a/a2.txt", filepath.Join(tmp, "a1.txt"), tc.opts)
+			require.NoError(t, err, "Overwrite failed")
+
+			gotContents, err := ioutil.ReadFile(filepath.Join(tmp, "a1.txt"))
+			require.NoError(t, err, "could not read file")
+			assert.Equal(t, tc.wantContents, string(gotContents), "invalid contents, want: %s, got: %s", tc.wantContents, gotContents)
+		})
+	}
+}