echo $scope.aliases | pivot to see all of your aliases (#3203)

* enable ability to see all aliases, pull in code from scope branch

* add in the alias tests

* add back in my changes to variables.rs after merging in andrasios changes from PR #3217

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

@@ -234,6 +234,8 @@ fn evaluate_reference(name: &str, ctx: &EvaluationContext, tag: Tag) -> Result<V
     match name {
         "$nu" => crate::evaluate::variables::nu(&ctx.scope, tag),
 
+        "$scope" => crate::evaluate::variables::scope(&ctx.scope.get_aliases(), tag),
+
         "$true" => Ok(Value {
             value: UntaggedValue::boolean(true),
             tag,

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

@@ -33,6 +33,19 @@ impl Scope {
         None
     }
 
+    pub fn get_aliases(&self) -> IndexMap<String, Vec<Spanned<String>>> {
+        let mut output = IndexMap::new();
+
+        for frame in self.frames.lock().iter().rev() {
+            for v in frame.aliases.iter() {
+                if !output.contains_key(v.0) {
+                    output.insert(v.0.clone(), v.1.clone());
+                }
+            }
+        }
+        output
+    }
+
     pub fn get_aliases_with_name(&self, name: &str) -> Option<Vec<Vec<Spanned<String>>>> {
         let aliases: Vec<_> = self
             .frames
@@ -71,6 +84,20 @@ impl Scope {
         }
     }
 
+    pub fn get_alias_names(&self) -> Vec<String> {
+        let mut names = vec![];
+
+        for frame in self.frames.lock().iter() {
+            let mut frame_command_names = frame.get_alias_names();
+            names.append(&mut frame_command_names);
+        }
+
+        names.dedup();
+        names.sort();
+
+        names
+    }
+
     pub fn get_command_names(&self) -> Vec<String> {
         let mut names = vec![];
 
@@ -274,6 +301,10 @@ impl ScopeFrame {
         self.aliases.contains_key(name)
     }
 
+    pub fn get_alias_names(&self) -> Vec<String> {
+        self.aliases.keys().map(|x| x.to_string()).collect()
+    }
+
     pub fn get_command_names(&self) -> Vec<String> {
         self.commands.keys().map(|x| x.to_string()).collect()
     }

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

@@ -1,8 +1,9 @@
 use crate::evaluate::scope::Scope;
+use indexmap::IndexMap;
 use nu_data::config::NuConfig;
 use nu_errors::ShellError;
 use nu_protocol::{Primitive, TaggedDictBuilder, UntaggedValue, Value};
-use nu_source::Tag;
+use nu_source::{Spanned, Tag};
 
 pub fn nu(scope: &Scope, tag: impl Into<Tag>) -> Result<Value, ShellError> {
     let tag = tag.into();
@@ -75,3 +76,28 @@ pub fn nu(scope: &Scope, tag: impl Into<Tag>) -> Result<Value, ShellError> {
 
     Ok(nu_dict.into_value())
 }
+
+pub fn scope(
+    aliases: &IndexMap<String, Vec<Spanned<String>>>,
+    tag: impl Into<Tag>,
+) -> Result<Value, ShellError> {
+    let tag = tag.into();
+
+    let mut scope_dict = TaggedDictBuilder::new(&tag);
+
+    let mut dict = TaggedDictBuilder::new(&tag);
+    for v in aliases.iter() {
+        let values = v.1.clone();
+        let mut vec = Vec::new();
+
+        for k in values.iter() {
+            vec.push(k.to_string());
+        }
+
+        let alias = vec.join(" ");
+        dict.insert_untagged(v.0, UntaggedValue::string(alias));
+    }
+
+    scope_dict.insert_value("aliases", dict.into_value());
+    Ok(scope_dict.into_value())
+}

crates/nu-engine/tests/evaluate/variables.rs

@@ -32,3 +32,39 @@ fn custom_config_path_variable_present() {
         );
     })
 }
+
+#[test]
+fn scope_variable_with_alias_present() {
+    Playground::setup("scope_variable_alias_test_1", |dirs, nu| {
+        let file = AbsolutePath::new(dirs.test().join("config.toml"));
+
+        nu.with_config(&file);
+        nu.with_files(vec![FileWithContent(
+            "config.toml",
+            "skip_welcome_message = true",
+        )]);
+
+        assert_that!(
+            nu.pipeline("alias t = time; echo $scope.aliases | get t"),
+            says().to_stdout("time")
+        );
+    })
+}
+
+#[test]
+fn scope_variable_with_correct_number_of_aliases_present() {
+    Playground::setup("scope_variable_alias_test_2", |dirs, nu| {
+        let file = AbsolutePath::new(dirs.test().join("config.toml"));
+
+        nu.with_config(&file);
+        nu.with_files(vec![FileWithContent(
+            "config.toml",
+            "skip_welcome_message = true",
+        )]);
+
+        assert_that!(
+            nu.pipeline("alias v = version; alias t = time; echo $scope.aliases | length -c"),
+            says().to_stdout("2")
+        );
+    })
+}