Add remove_ attribute

docs/REFERENCE.md

@@ -424,6 +424,7 @@ to as "attributes":
 | `modify_`    | Treat the contents as a script that modifies an existing file.                 |
 | `once_`      | Run script once.                                                               |
 | `private_`   | Remove all group and world permissions from the target file or directory.      |
+| `remove_`    | Remove the entry if it exists.                                                 |
 | `run_`       | Treat the contents as a script to run.                                         |
 | `symlink_`   | Create a symlink instead of a regular file.                                    |
 
@@ -441,6 +442,7 @@ prefixes is important.
 | Regular file  | File        | `encrypted_`, `private_`, `executable_`, `dot_`                       | `.tmpl`          |
 | Create file   | File        | `create_`, `encrypted_`, `private_`, `executable_`, `dot_`            | `.tmpl`          |
 | Modify file   | File        | `modify_`, `encrypted_`, `private_`, `executable_`, `dot_`            | `.tmpl`          |
+| Remove        | File        | `remove_`, `dot_`                                                     | *none*           |
 | Script        | File        | `run_`, `once_`, `before_` or `after_`                                | `.tmpl`          |
 | Symbolic link | File        | `symlink_`, `dot_`,                                                   | `.tmpl`          |
 
@@ -495,6 +497,13 @@ new contents are read from the scripts standard output.
 
 ---
 
+#### Remove entry
+
+Files with the `remove_` prefix will cause the corresponding entry (file,
+directory, or symlink) to be removed in the target state.
+
+---
+
 ### Directories
 
 Directories are represented by regular directories in the source state. The

internal/chezmoi/attr.go

@@ -15,6 +15,7 @@ const (
 	SourceFileTypeCreate SourceFileTargetType = iota
 	SourceFileTypeFile
 	SourceFileTypeModify
+	SourceFileTypeRemove
 	SourceFileTypeScript
 	SourceFileTypeSymlink
 )
@@ -125,6 +126,9 @@ func parseFileAttr(sourceName, encryptedSuffix string) FileAttr {
 			name = mustTrimPrefix(name, executablePrefix)
 			executable = true
 		}
+	case strings.HasPrefix(name, removePrefix):
+		sourceFileType = SourceFileTypeRemove
+		name = mustTrimPrefix(name, removePrefix)
 	case strings.HasPrefix(name, runPrefix):
 		sourceFileType = SourceFileTypeScript
 		name = mustTrimPrefix(name, runPrefix)
@@ -240,6 +244,8 @@ func (fa FileAttr) SourceName(encryptedSuffix string) string {
 		if fa.Executable {
 			sourceName += executablePrefix
 		}
+	case SourceFileTypeRemove:
+		sourceName = removePrefix
 	case SourceFileTypeScript:
 		sourceName = runPrefix
 		if fa.Once {

internal/chezmoi/attr_test.go

@@ -133,6 +133,13 @@ func TestFileAttr(t *testing.T) {
 		Private:    []bool{false, true},
 		Template:   []bool{false, true},
 	}))
+	require.NoError(t, combinator.Generate(&fas, struct {
+		Type       SourceFileTargetType
+		TargetName []string
+	}{
+		Type:       SourceFileTypeRemove,
+		TargetName: targetNames,
+	}))
 	require.NoError(t, combinator.Generate(&fas, struct {
 		Type       SourceFileTargetType
 		TargetName []string

internal/chezmoi/chezmoi.go

@@ -37,6 +37,7 @@ const (
 	modifyPrefix     = "modify_"
 	oncePrefix       = "once_"
 	privatePrefix    = "private_"
+	removePrefix     = "remove_"
 	runPrefix        = "run_"
 	symlinkPrefix    = "symlink_"
 	literalSuffix    = ".literal"
@@ -57,7 +58,7 @@ const (
 
 var (
 	dirPrefixRegexp  = regexp.MustCompile(`\A(dot|exact|literal|private)_`)
-	filePrefixRegexp = regexp.MustCompile(`\A(after|before|create|dot|empty|encrypted|executable|literal|modify|once|private|run|symlink)_`)
+	filePrefixRegexp = regexp.MustCompile(`\A(after|before|create|dot|empty|encrypted|executable|literal|modify|once|private|remove|run|symlink)_`)
 	fileSuffixRegexp = regexp.MustCompile(`\.(literal|tmpl)\z`)
 )
 

internal/chezmoi/sourcestate.go

@@ -1230,6 +1230,14 @@ func (s *SourceState) newModifyTargetStateEntryFunc(sourceRelPath SourceRelPath,
 	}
 }
 
+// newRemoveTargetStateEntryFunc returns a targetStateEntryFunc that removes a
+// target.
+func (s *SourceState) newRemoveTargetStateEntryFunc(sourceRelPath SourceRelPath, fileAttr FileAttr) targetStateEntryFunc {
+	return func(destSystem System, destAbsPath AbsPath) (TargetStateEntry, error) {
+		return &TargetStateRemove{}, nil
+	}
+}
+
 // newScriptTargetStateEntryFunc returns a targetStateEntryFunc that returns a
 // script with sourceLazyContents.
 func (s *SourceState) newScriptTargetStateEntryFunc(sourceRelPath SourceRelPath, fileAttr FileAttr, targetRelPath RelPath, sourceLazyContents *lazyContents, interpreter *Interpreter) targetStateEntryFunc {
@@ -1314,6 +1322,8 @@ func (s *SourceState) newSourceStateFile(sourceRelPath SourceRelPath, fileAttr F
 			targetRelPath = targetRelPath[:len(targetRelPath)-len(ext)-1]
 		}
 		targetStateEntryFunc = s.newModifyTargetStateEntryFunc(sourceRelPath, fileAttr, sourceLazyContents, interpreter)
+	case SourceFileTypeRemove:
+		targetStateEntryFunc = s.newRemoveTargetStateEntryFunc(sourceRelPath, fileAttr)
 	case SourceFileTypeScript:
 		// If the script has an extension, determine if it indicates an
 		// interpreter to use.

internal/cmd/testdata/scripts/remove.txt

@@ -19,3 +19,18 @@ exists $HOME/.executable
 ! chezmoi remove --force $HOME${/}.newfile $HOME${/}.executable
 stderr 'not in source state'
 exists $HOME/.executable
+
+chhome home2/user
+
+# test that chezmoi apply removes a file and a directory
+exists $HOME/.file
+exists $HOME/.dir
+chezmoi apply
+! exists $HOME/.file
+! exists $HOME/.dir
+
+-- home2/user/.dir/.keep --
+-- home2/user/.file --
+# contents of .file
+-- home2/user/.local/share/chezmoi/remove_dot_file --
+-- home2/user/.local/share/chezmoi/remove_dot_dir --