a new command to query the nushell internals (#3704)

* a new command to query the nushell internals

* added signature

* a little cleanup

crates/nu-engine/src/evaluate/mod.rs

@@ -2,7 +2,7 @@ pub(crate) mod block;
 pub(crate) mod evaluate_args;
 pub mod evaluator;
 pub(crate) mod expr;
-pub(crate) mod internal;
+pub mod internal;
 pub(crate) mod operator;
 pub(crate) mod scope;
 pub(crate) mod variables;

crates/nu-engine/src/evaluate/scope.rs

@@ -65,6 +65,20 @@ impl Scope {
         output.sorted_by(|k1, _v1, k2, _v2| k1.cmp(k2)).collect()
     }
 
+    pub fn get_commands_info(&self) -> IndexMap<String, Command> {
+        let mut output: IndexMap<String, Command> = IndexMap::new();
+
+        for frame in self.frames.lock().iter().rev() {
+            for (name, command) in frame.commands.iter() {
+                if !output.contains_key(name) {
+                    output.insert(name.clone(), command.clone());
+                }
+            }
+        }
+
+        output.sorted_by(|k1, _v1, k2, _v2| k1.cmp(k2)).collect()
+    }
+
     pub fn get_variable_names(&self) -> Vec<String> {
         self.get_vars().iter().map(|(k, _)| k.to_string()).collect()
     }

crates/nu-engine/src/lib.rs

@@ -3,7 +3,7 @@ mod command_args;
 mod config_holder;
 pub mod documentation;
 mod env;
-mod evaluate;
+pub mod evaluate;
 pub mod evaluation_context;
 mod example;
 pub mod filesystem;

crates/nu-engine/src/plugin/run_plugin.rs

@@ -111,9 +111,21 @@ impl WholeStreamCommand for PluginFilter {
         &self.config.usage
     }
 
+    fn extra_usage(&self) -> &str {
+        &self.config.extra_usage
+    }
+
     fn run_with_actions(&self, args: CommandArgs) -> Result<ActionStream, ShellError> {
         run_filter(self.path.clone(), args)
     }
+
+    fn is_plugin(&self) -> bool {
+        true
+    }
+
+    fn is_builtin(&self) -> bool {
+        false
+    }
 }
 
 fn run_filter(path: String, args: CommandArgs) -> Result<ActionStream, ShellError> {
@@ -383,9 +395,21 @@ impl WholeStreamCommand for PluginSink {
         &self.config.usage
     }
 
+    fn extra_usage(&self) -> &str {
+        &self.config.extra_usage
+    }
+
     fn run_with_actions(&self, args: CommandArgs) -> Result<ActionStream, ShellError> {
         run_sink(self.path.clone(), args)
     }
+
+    fn is_plugin(&self) -> bool {
+        true
+    }
+
+    fn is_builtin(&self) -> bool {
+        false
+    }
 }
 
 fn run_sink(path: String, args: CommandArgs) -> Result<ActionStream, ShellError> {

crates/nu-engine/src/whole_stream_command.rs

@@ -47,19 +47,38 @@ pub trait WholeStreamCommand: Send + Sync {
     }
 
     // Commands that are not meant to be run by users
-    fn is_internal(&self) -> bool {
+    fn is_private(&self) -> bool {
         false
     }
 
     fn examples(&self) -> Vec<Example> {
         Vec::new()
     }
+
+    // This is a built-in command
+    fn is_builtin(&self) -> bool {
+        true
+    }
+
+    // Is a sub command
+    fn is_sub(&self) -> bool {
+        self.name().contains(' ')
+    }
+
+    // Is a plugin command
+    fn is_plugin(&self) -> bool {
+        false
+    }
+
+    // Is a custom command i.e. def blah [] { }
+    fn is_custom(&self) -> bool {
+        false
+    }
 }
 
 // Custom commands are blocks, so we can use the information in the block to also
 // implement a WholeStreamCommand
 #[allow(clippy::suspicious_else_formatting)]
-
 impl WholeStreamCommand for Arc<Block> {
     fn name(&self) -> &str {
         &self.params.name
@@ -73,6 +92,10 @@ impl WholeStreamCommand for Arc<Block> {
         &self.params.usage
     }
 
+    fn extra_usage(&self) -> &str {
+        &self.params.extra_usage
+    }
+
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
         let call_info = args.call_info.clone();
 
@@ -184,13 +207,21 @@ impl WholeStreamCommand for Arc<Block> {
         false
     }
 
-    fn is_internal(&self) -> bool {
+    fn is_private(&self) -> bool {
         false
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![]
     }
+
+    fn is_custom(&self) -> bool {
+        true
+    }
+
+    fn is_builtin(&self) -> bool {
+        false
+    }
 }
 
 #[derive(Clone)]
@@ -228,6 +259,10 @@ impl Command {
         self.0.usage()
     }
 
+    pub fn extra_usage(&self) -> &str {
+        self.0.extra_usage()
+    }
+
     pub fn examples(&self) -> Vec<Example> {
         self.0.examples()
     }
@@ -260,13 +295,29 @@ impl Command {
         self.0.is_binary()
     }
 
-    pub fn is_internal(&self) -> bool {
-        self.0.is_internal()
+    pub fn is_private(&self) -> bool {
+        self.0.is_private()
     }
 
     pub fn stream_command(&self) -> &dyn WholeStreamCommand {
         &*self.0
     }
+
+    pub fn is_builtin(&self) -> bool {
+        self.0.is_builtin()
+    }
+
+    pub fn is_sub(&self) -> bool {
+        self.0.is_sub()
+    }
+
+    pub fn is_plugin(&self) -> bool {
+        self.0.is_plugin()
+    }
+
+    pub fn is_custom(&self) -> bool {
+        self.0.is_custom()
+    }
 }
 
 pub fn whole_stream_command(command: impl WholeStreamCommand + 'static) -> Command {