Extend 'Shell' with open and save capabilities (#2165)

* Extend 'Shell' with open and save capabilities

* clippy fix

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

@@ -1,17 +1,14 @@
-use crate::commands::classified::maybe_text_codec::{MaybeTextCodec, StringOrBinary};
+use crate::commands::classified::maybe_text_codec::StringOrBinary;
+use crate::commands::constants::BAT_LANGUAGES;
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
-use futures_codec::FramedRead;
+use encoding_rs::{Encoding, UTF_8};
+use futures_util::StreamExt;
+use log::debug;
 use nu_errors::ShellError;
 use nu_protocol::{CommandAction, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
 use nu_source::{AnchorLocation, Span, Tagged};
 use std::path::PathBuf;
-extern crate encoding_rs;
-use crate::commands::constants::BAT_LANGUAGES;
-use encoding_rs::*;
-use futures::prelude::*;
-use log::debug;
-use std::fs::File;
 
 pub struct Open;
 
@@ -103,6 +100,7 @@ pub fn get_encoding(opt: Option<Tagged<String>>) -> Result<&'static Encoding, Sh
 async fn open(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
     let cwd = PathBuf::from(args.shell_manager.path());
     let registry = registry.clone();
+    let shell_manager = args.shell_manager.clone();
 
     let (
         OpenArgs {
@@ -159,17 +157,8 @@ async fn open(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStr
     } else {
         Some(get_encoding(encoding)?)
     };
-    let f = File::open(&path).map_err(|e| {
-        ShellError::labeled_error(
-            format!("Error opening file: {:?}", e),
-            "Error opening file",
-            path.span(),
-        )
-    })?;
-    let async_reader = futures::io::AllowStdIo::new(f);
-    let sob_stream = FramedRead::new(async_reader, MaybeTextCodec::new(with_encoding))
-        .map_err(|e| ShellError::unexpected(format!("AsyncRead failed in open function: {:?}", e)))
-        .into_stream();
+
+    let sob_stream = shell_manager.open(&path.item, path.tag.span, with_encoding)?;
 
     let final_stream = sob_stream.map(move |x| {
         // The tag that will used when returning a Value

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

@@ -170,7 +170,7 @@ async fn save(
     let host = raw_args.host.clone();
     let ctrl_c = raw_args.ctrl_c.clone();
     let current_errors = raw_args.current_errors.clone();
-    let shell_manager = raw_args.shell_manager.clone();
+    let mut shell_manager = raw_args.shell_manager.clone();
 
     let head = raw_args.call_info.args.head.clone();
     let (
@@ -219,7 +219,7 @@ async fn save(
                         host,
                         ctrl_c,
                         current_errors,
-                        shell_manager,
+                        shell_manager: shell_manager.clone(),
                         call_info: UnevaluatedCallInfo {
                             args: nu_protocol::hir::Call {
                                 head,
@@ -252,14 +252,7 @@ async fn save(
     };
 
     match content {
-        Ok(save_data) => match std::fs::write(full_path, save_data) {
-            Ok(_) => Ok(OutputStream::empty()),
-            Err(e) => Err(ShellError::labeled_error(
-                e.to_string(),
-                "IO error while saving",
-                name,
-            )),
-        },
+        Ok(save_data) => shell_manager.save(&full_path, &save_data, name.span),
         Err(e) => Err(e),
     }
 }

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

@@ -18,6 +18,11 @@ use std::collections::HashMap;
 use std::io::{Error, ErrorKind};
 use std::path::{Path, PathBuf};
 
+use crate::commands::classified::maybe_text_codec::{MaybeTextCodec, StringOrBinary};
+use encoding_rs::Encoding;
+use futures_codec::FramedRead;
+use futures_util::TryStreamExt;
+
 #[cfg(unix)]
 use std::os::unix::fs::PermissionsExt;
 
@@ -679,6 +684,45 @@ impl Shell for FilesystemShell {
         self.path = path.to_string_lossy().to_string();
     }
 
+    fn open(
+        &self,
+        path: &PathBuf,
+        name: Span,
+        with_encoding: Option<&'static Encoding>,
+    ) -> Result<BoxStream<'static, Result<StringOrBinary, ShellError>>, ShellError> {
+        let f = std::fs::File::open(&path).map_err(|e| {
+            ShellError::labeled_error(
+                format!("Error opening file: {:?}", e),
+                "Error opening file",
+                name,
+            )
+        })?;
+        let async_reader = futures::io::AllowStdIo::new(f);
+        let sob_stream = FramedRead::new(async_reader, MaybeTextCodec::new(with_encoding))
+            .map_err(|e| {
+                ShellError::unexpected(format!("AsyncRead failed in open function: {:?}", e))
+            })
+            .into_stream();
+
+        Ok(sob_stream.boxed())
+    }
+
+    fn save(
+        &mut self,
+        full_path: &PathBuf,
+        save_data: &[u8],
+        name: Span,
+    ) -> Result<OutputStream, ShellError> {
+        match std::fs::write(full_path, save_data) {
+            Ok(_) => Ok(OutputStream::empty()),
+            Err(e) => Err(ShellError::labeled_error(
+                e.to_string(),
+                "IO error while saving",
+                name,
+            )),
+        }
+    }
+
     fn complete(
         &self,
         line: &str,

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

@@ -12,6 +12,8 @@ use crate::shell::shell::Shell;
 use std::ffi::OsStr;
 use std::path::PathBuf;
 
+use crate::commands::classified::maybe_text_codec::StringOrBinary;
+use encoding_rs::Encoding;
 use nu_errors::ShellError;
 use nu_protocol::{
     Primitive, ReturnSuccess, ShellTypeName, TaggedDictBuilder, UntaggedValue, Value,
@@ -197,6 +199,28 @@ impl Shell for HelpShell {
         Ok(OutputStream::empty())
     }
 
+    fn open(
+        &self,
+        _path: &PathBuf,
+        _name: Span,
+        _with_encoding: Option<&'static Encoding>,
+    ) -> Result<BoxStream<'static, Result<StringOrBinary, ShellError>>, ShellError> {
+        Err(ShellError::unimplemented(
+            "open on help shell is not supported",
+        ))
+    }
+
+    fn save(
+        &mut self,
+        _path: &PathBuf,
+        _contents: &[u8],
+        _name: Span,
+    ) -> Result<OutputStream, ShellError> {
+        Err(ShellError::unimplemented(
+            "save on help shell is not supported",
+        ))
+    }
+
     fn complete(
         &self,
         line: &str,

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

@@ -1,4 +1,5 @@
 use crate::commands::cd::CdArgs;
+use crate::commands::classified::maybe_text_codec::StringOrBinary;
 use crate::commands::command::EvaluatedWholeStreamCommandArgs;
 use crate::commands::cp::CopyArgs;
 use crate::commands::ls::LsArgs;
@@ -7,6 +8,7 @@ use crate::commands::move_::mv::Arguments as MvArgs;
 use crate::commands::rm::RemoveArgs;
 use crate::prelude::*;
 use crate::stream::OutputStream;
+use encoding_rs::Encoding;
 use nu_errors::ShellError;
 use std::path::PathBuf;
 
@@ -28,6 +30,18 @@ pub trait Shell: std::fmt::Debug {
     fn path(&self) -> String;
     fn pwd(&self, args: EvaluatedWholeStreamCommandArgs) -> Result<OutputStream, ShellError>;
     fn set_path(&mut self, path: String);
+    fn open(
+        &self,
+        path: &PathBuf,
+        name: Span,
+        with_encoding: Option<&'static Encoding>,
+    ) -> Result<BoxStream<'static, Result<StringOrBinary, ShellError>>, ShellError>;
+    fn save(
+        &mut self,
+        path: &PathBuf,
+        contents: &[u8],
+        name: Span,
+    ) -> Result<OutputStream, ShellError>;
 
     fn complete(
         &self,

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

@@ -1,4 +1,5 @@
 use crate::commands::cd::CdArgs;
+use crate::commands::classified::maybe_text_codec::StringOrBinary;
 use crate::commands::command::EvaluatedWholeStreamCommandArgs;
 use crate::commands::cp::CopyArgs;
 use crate::commands::ls::LsArgs;
@@ -9,6 +10,7 @@ use crate::prelude::*;
 use crate::shell::filesystem_shell::FilesystemShell;
 use crate::shell::shell::Shell;
 use crate::stream::OutputStream;
+use encoding_rs::Encoding;
 use nu_errors::ShellError;
 use parking_lot::Mutex;
 use std::error::Error;
@@ -81,6 +83,25 @@ impl ShellManager {
         self.shells.lock()[self.current_shell()].set_path(path)
     }
 
+    pub fn open(
+        &self,
+        full_path: &PathBuf,
+        name: Span,
+        with_encoding: Option<&'static Encoding>,
+    ) -> Result<impl Stream<Item = Result<StringOrBinary, ShellError>> + Send + 'static, ShellError>
+    {
+        self.shells.lock()[self.current_shell()].open(full_path, name, with_encoding)
+    }
+
+    pub fn save(
+        &mut self,
+        full_path: &PathBuf,
+        save_data: &[u8],
+        name: Span,
+    ) -> Result<OutputStream, ShellError> {
+        self.shells.lock()[self.current_shell()].save(full_path, save_data, name)
+    }
+
     pub fn complete(
         &self,
         line: &str,

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

@@ -9,6 +9,8 @@ use crate::prelude::*;
 use crate::shell::shell::Shell;
 use crate::utils::ValueStructure;
 
+use crate::commands::classified::maybe_text_codec::StringOrBinary;
+use encoding_rs::Encoding;
 use std::ffi::OsStr;
 use std::path::{Path, PathBuf};
 
@@ -230,6 +232,28 @@ impl Shell for ValueShell {
         self.path = path;
     }
 
+    fn open(
+        &self,
+        _path: &PathBuf,
+        _name: Span,
+        _with_encoding: Option<&'static Encoding>,
+    ) -> Result<BoxStream<'static, Result<StringOrBinary, ShellError>>, ShellError> {
+        Err(ShellError::unimplemented(
+            "open on help shell is not supported",
+        ))
+    }
+
+    fn save(
+        &mut self,
+        _path: &PathBuf,
+        _contents: &[u8],
+        _name: Span,
+    ) -> Result<OutputStream, ShellError> {
+        Err(ShellError::unimplemented(
+            "save on help shell is not supported",
+        ))
+    }
+
     fn complete(
         &self,
         line: &str,