introducing the find command (#3971)

* introducing the `find` command

* added tests

* merged main to accomodate "rest" changes

* test fix

crates/nu-command/src/commands/core_commands/find.rs

@@ -0,0 +1,110 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{Dictionary, Signature, SyntaxShape, UntaggedValue, Value};
+
+pub struct Find;
+
+impl WholeStreamCommand for Find {
+    fn name(&self) -> &str {
+        "find"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("find").rest("rest", SyntaxShape::String, "search term")
+    }
+
+    fn usage(&self) -> &str {
+        "Find text in the output of a previous command"
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        find(args)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Search pipeline output for multiple terms",
+                example: r#"ls | find toml md sh"#,
+                result: None,
+            },
+            Example {
+                description: "Search strings for term(s)",
+                example: r#"echo Cargo.toml | find toml"#,
+                result: Some(vec![Value::from("Cargo.toml")]),
+            },
+            Example {
+                description: "Search a number list for term(s)",
+                example: r#"[1 2 3 4 5] | find 5"#,
+                result: Some(vec![UntaggedValue::int(5).into()]),
+            },
+            Example {
+                description: "Search string list for term(s)",
+                example: r#"[moe larry curly] | find l"#,
+                result: Some(vec![Value::from("larry"), Value::from("curly")]),
+            },
+        ]
+    }
+}
+
+fn row_contains(row: &Dictionary, search_terms: Vec<String>) -> bool {
+    for term in search_terms {
+        for (k, v) in row.entries.iter() {
+            let key = k.to_string().trim().to_lowercase();
+            let value = v.convert_to_string().trim().to_lowercase();
+            if key.contains(&term) || value.contains(&term) {
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
+fn find(args: CommandArgs) -> Result<OutputStream, ShellError> {
+    let rest: Vec<Value> = args.rest(0)?;
+
+    Ok(args
+        .input
+        .filter(move |row| match &row.value {
+            UntaggedValue::Row(row) => {
+                let sterms: Vec<String> = rest
+                    .iter()
+                    .map(|t| t.convert_to_string().trim().to_lowercase())
+                    .collect();
+                row_contains(row, sterms)
+            }
+            UntaggedValue::Primitive(_p) => {
+                // eprint!("prim {}", p.type_name());
+                let sterms: Vec<String> = rest
+                    .iter()
+                    .map(|t| t.convert_to_string().trim().to_lowercase())
+                    .collect();
+
+                let prim_string = &row.convert_to_string().trim().to_lowercase();
+                for term in sterms {
+                    if prim_string.contains(&term) {
+                        return true;
+                    }
+                }
+
+                false
+            }
+            _ => false,
+        })
+        .into_output_stream())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Find;
+    use super::ShellError;
+
+    #[test]
+    fn examples_work_as_expected() -> Result<(), ShellError> {
+        use crate::examples::test as test_examples;
+
+        test_examples(Find {})
+    }
+}

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

@@ -4,6 +4,7 @@ mod def;
 mod describe;
 mod do_;
 pub(crate) mod echo;
+mod find;
 mod help;
 mod history;
 mod if_;
@@ -27,6 +28,7 @@ pub use def::Def;
 pub use describe::Describe;
 pub use do_::Do;
 pub use echo::Echo;
+pub use find::Find;
 pub use help::Help;
 pub use history::History;
 pub use if_::If;