allow for easy reset of config files with a single command (#6041)

* allow for easy config reset with a single command

* add slightly better help, rebase

* add option to make no backups, make all backups unique through including UNIX Epoch Time in the filename

* time is now formatted in rfc3339

* time is now formatted in a window-friendly format

crates/nu-command/src/default_context.rs

@@ -343,6 +343,7 @@ pub fn create_default_context(cwd: impl AsRef<Path>) -> EngineState {
             WithEnv,
             ConfigNu,
             ConfigEnv,
+            ConfigReset,
             ConfigMeta,
         };
 

crates/nu-command/src/env/config/config_reset.rs

@@ -0,0 +1,112 @@
+use chrono::Local;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, PipelineData, ShellError, Signature,
+};
+use std::io::Write;
+
+#[derive(Clone)]
+pub struct ConfigReset;
+
+impl Command for ConfigReset {
+    fn name(&self) -> &str {
+        "config reset"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .switch("nu", "reset only nu config, config.nu", Some('n'))
+            .switch("env", "reset only env config, env.nu", Some('e'))
+            .switch("without-backup", "do not make a backup", Some('w'))
+            .category(Category::Env)
+    }
+
+    fn usage(&self) -> &str {
+        "Reset nushell environment configurations to default, and saves old config files in the config location as oldconfig.nu and oldenv.nu"
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "reset nushell configuration files",
+            example: "config reset",
+            result: None,
+        }]
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let only_nu = call.has_flag("nu");
+        let only_env = call.has_flag("env");
+        let no_backup = call.has_flag("without-backup");
+        let span = call.head;
+        let mut config_path = match nu_path::config_dir() {
+            Some(path) => path,
+            None => {
+                return Err(ShellError::GenericError(
+                    "Could not find config path".to_string(),
+                    "Could not find config path".to_string(),
+                    None,
+                    None,
+                    Vec::new(),
+                ));
+            }
+        };
+        config_path.push("nushell");
+        if !only_env {
+            let mut nu_config = config_path.clone();
+            nu_config.push("config.nu");
+            let config_file = include_str!("../../../../../docs/sample_config/default_config.nu");
+            if !no_backup {
+                let mut backup_path = config_path.clone();
+                backup_path.push(format!(
+                    "oldconfig-{}.nu",
+                    Local::now().format("%F-%H-%M-%S"),
+                ));
+                if std::fs::rename(nu_config.clone(), backup_path).is_err() {
+                    return Err(ShellError::FileNotFoundCustom(
+                        "config.nu could not be backed up".into(),
+                        span,
+                    ));
+                }
+            }
+            if let Ok(mut file) = std::fs::File::create(nu_config) {
+                if writeln!(&mut file, "{}", config_file).is_err() {
+                    return Err(ShellError::FileNotFoundCustom(
+                        "config.nu could not be written to".into(),
+                        span,
+                    ));
+                }
+            }
+        }
+        if !only_nu {
+            let mut env_config = config_path.clone();
+            env_config.push("env.nu");
+            let config_file = include_str!("../../../../../docs/sample_config/default_env.nu");
+            if !no_backup {
+                let mut backup_path = config_path.clone();
+                backup_path.push(format!("oldenv-{}.nu", Local::now().format("%F-%H-%M-%S"),));
+                if std::fs::rename(env_config.clone(), backup_path).is_err() {
+                    return Err(ShellError::FileNotFoundCustom(
+                        "env.nu could not be backed up".into(),
+                        span,
+                    ));
+                }
+            }
+            if let Ok(mut file) = std::fs::File::create(env_config) {
+                if writeln!(&mut file, "{}", config_file).is_err() {
+                    return Err(ShellError::FileNotFoundCustom(
+                        "env.nu could not be written to".into(),
+                        span,
+                    ));
+                }
+            }
+        }
+        Ok(PipelineData::new(span))
+    }
+}

crates/nu-command/src/env/config/mod.rs

@@ -1,7 +1,9 @@
 mod config_;
 mod config_env;
 mod config_nu;
+mod config_reset;
 mod utils;
 pub use config_::ConfigMeta;
 pub use config_env::ConfigEnv;
 pub use config_nu::ConfigNu;
+pub use config_reset::ConfigReset;

crates/nu-command/src/env/mod.rs

@@ -7,6 +7,7 @@ mod with_env;
 pub use config::ConfigEnv;
 pub use config::ConfigMeta;
 pub use config::ConfigNu;
+pub use config::ConfigReset;
 pub use env_command::Env;
 pub use let_env::LetEnv;
 pub use load_env::LoadEnv;