Ported ignore command to engine-q (#621)

* Ported `ignore` command to engine-q

* Format ignore command

crates/nu-command/src/core_commands/ignore.rs

@@ -0,0 +1,48 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Category, Example, PipelineData, Signature};
+
+#[derive(Clone)]
+pub struct Ignore;
+
+impl Command for Ignore {
+    fn name(&self) -> &str {
+        "ignore"
+    }
+
+    fn usage(&self) -> &str {
+        "Ignore the output of the previous command in the pipeline"
+    }
+
+    fn signature(&self) -> nu_protocol::Signature {
+        Signature::build("ignore").category(Category::Core)
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        Ok(PipelineData::new(call.head))
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Ignore the output of an echo command",
+            example: "echo done | ignore",
+            result: None,
+        }]
+    }
+}
+
+#[cfg(test)]
+mod test {
+    #[test]
+    fn test_examples() {
+        use super::Ignore;
+        use crate::test_examples;
+        test_examples(Ignore {})
+    }
+}

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

@@ -12,6 +12,7 @@ mod help;
 mod hide;
 mod history;
 mod if_;
+mod ignore;
 mod let_;
 mod metadata;
 mod module;
@@ -33,6 +34,7 @@ pub use help::Help;
 pub use hide::Hide;
 pub use history::History;
 pub use if_::If;
+pub use ignore::Ignore;
 pub use let_::Let;
 pub use metadata::Metadata;
 pub use module::Module;

crates/nu-command/src/default_context.rs

@@ -37,6 +37,7 @@ pub fn create_default_context() -> EngineState {
             Hide,
             History,
             If,
+            Ignore,
             Let,
             Metadata,
             Module,