Display either dir metadata size or dir apparent size in ls (#1696)

* Show dir size in ls command

* Add the option to show the apparent directory size via `ls --du`

crates/nu-cli/src/commands/du.rs

@@ -143,7 +143,7 @@ fn du(args: DuArgs, ctx: RunnableContext) -> Result<OutputStream, ShellError> {
     Ok(stream.to_output_stream())
 }
 
-struct DirBuilder {
+pub struct DirBuilder {
     tag: Tag,
     min: Option<u64>,
     deref: bool,
@@ -151,7 +151,25 @@ struct DirBuilder {
     all: bool,
 }
 
-struct DirInfo {
+impl DirBuilder {
+    pub fn new(
+        tag: Tag,
+        min: Option<u64>,
+        deref: bool,
+        exclude: Option<Pattern>,
+        all: bool,
+    ) -> DirBuilder {
+        DirBuilder {
+            tag,
+            min,
+            deref,
+            exclude,
+            all,
+        }
+    }
+}
+
+pub struct DirInfo {
     dirs: Vec<DirInfo>,
     files: Vec<FileInfo>,
     errors: Vec<ShellError>,
@@ -194,7 +212,7 @@ impl FileInfo {
 }
 
 impl DirInfo {
-    fn new(path: impl Into<PathBuf>, params: &DirBuilder, depth: Option<u64>) -> Self {
+    pub fn new(path: impl Into<PathBuf>, params: &DirBuilder, depth: Option<u64>) -> Self {
         let path = path.into();
 
         let mut s = Self {
@@ -274,6 +292,10 @@ impl DirInfo {
         self.errors.push(e);
         self
     }
+
+    pub fn get_size(&self) -> u64 {
+        self.size
+    }
 }
 
 fn glob_err_into(e: GlobError) -> ShellError {

crates/nu-cli/src/commands/ls.rs

@@ -16,6 +16,8 @@ pub struct LsArgs {
     pub short_names: bool,
     #[serde(rename = "with-symlink-targets")]
     pub with_symlink_targets: bool,
+    #[serde(rename = "du")]
+    pub du: bool,
 }
 
 impl WholeStreamCommand for Ls {
@@ -46,6 +48,11 @@ impl WholeStreamCommand for Ls {
                 "display the paths to the target files that symlinks point to",
                 Some('w'),
             )
+            .switch(
+                "du",
+                "display the apparent directory size in place of the directory metadata size",
+                Some('d'),
+            )
     }
 
     fn usage(&self) -> &str {

crates/nu-cli/src/data/files.rs

@@ -1,3 +1,4 @@
+use crate::commands::du::{DirBuilder, DirInfo};
 use crate::prelude::*;
 use nu_errors::ShellError;
 use nu_protocol::{TaggedDictBuilder, UntaggedValue, Value};
@@ -38,6 +39,7 @@ pub(crate) fn dir_entry_dict(
     full: bool,
     short_name: bool,
     with_symlink_targets: bool,
+    du: bool,
 ) -> Result<Value, ShellError> {
     let tag = tag.into();
     let mut dict = TaggedDictBuilder::new(&tag);
@@ -125,8 +127,27 @@ pub(crate) fn dir_entry_dict(
     let mut size_untagged_value: UntaggedValue = UntaggedValue::nothing();
 
     if let Some(md) = metadata {
-        if md.is_file() {
-            size_untagged_value = UntaggedValue::bytes(md.len() as u64);
+        if md.is_dir() {
+            let dir_size: u64 = if du {
+                let params = DirBuilder::new(
+                    Tag {
+                        anchor: None,
+                        span: Span::new(0, 2),
+                    },
+                    None,
+                    false,
+                    None,
+                    false,
+                );
+
+                DirInfo::new(filename, &params, None).get_size()
+            } else {
+                md.len()
+            };
+
+            size_untagged_value = UntaggedValue::bytes(dir_size);
+        } else if md.is_file() {
+            size_untagged_value = UntaggedValue::bytes(md.len());
         } else if md.file_type().is_symlink() {
             if let Ok(symlink_md) = filename.symlink_metadata() {
                 size_untagged_value = UntaggedValue::bytes(symlink_md.len() as u64);

crates/nu-cli/src/shell/filesystem_shell.rs

@@ -107,6 +107,7 @@ impl Shell for FilesystemShell {
             full,
             short_names,
             with_symlink_targets,
+            du,
         }: LsArgs,
         context: &RunnableContext,
     ) -> Result<OutputStream, ShellError> {
@@ -170,7 +171,8 @@ impl Shell for FilesystemShell {
                     name_tag.clone(),
                     full,
                     short_names,
-                    with_symlink_targets
+                    with_symlink_targets,
+                    du,
                 )
                 .map(|entry| ReturnSuccess::Value(entry.into()))?;