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;

crates/nu-command/src/default_context.rs

@@ -21,6 +21,7 @@ pub fn create_default_context(interactive: bool) -> Result<EvaluationContext, Bo
             whole_stream_command(Unalias),
             whole_stream_command(Ignore),
             whole_stream_command(Tutor),
+            whole_stream_command(Find),
             // System/file operations
             whole_stream_command(Exec),
             whole_stream_command(Pwd),

crates/nu-command/tests/commands/find.rs

@@ -0,0 +1,111 @@
+use nu_test_support::fs::Stub::EmptyFile;
+use nu_test_support::playground::Playground;
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn find_with_list_search_with_string() {
+    let actual = nu!(
+    cwd: ".", pipeline(
+    r#"
+        [moe larry curly] | find moe
+    "#
+    ));
+
+    assert_eq!(actual.out, "moe");
+}
+
+#[test]
+fn find_with_list_search_with_char() {
+    let actual = nu!(
+    cwd: ".", pipeline(
+    r#"
+        [moe larry curly] | find l | to json
+    "#
+    ));
+
+    assert_eq!(actual.out, r#"["larry","curly"]"#);
+}
+
+#[test]
+fn find_with_list_search_with_number() {
+    let actual = nu!(
+    cwd: ".", pipeline(
+    r#"
+        [1 2 3 4 5] | find 3
+    "#
+    ));
+
+    assert_eq!(actual.out, "3");
+}
+
+#[test]
+fn find_with_string_search_with_string() {
+    let actual = nu!(
+    cwd: ".", pipeline(
+    r#"
+        echo Cargo.toml | find toml
+    "#
+    ));
+
+    assert_eq!(actual.out, "Cargo.toml");
+}
+
+#[test]
+fn find_with_string_search_with_string_not_found() {
+    let actual = nu!(
+    cwd: ".", pipeline(
+    r#"
+        [moe larry curly] | find shemp
+    "#
+    ));
+
+    assert_eq!(actual.out, "");
+}
+
+#[test]
+fn find_with_filepath_search_with_string() {
+    Playground::setup("filepath_test_1", |dirs, sandbox| {
+        sandbox.with_files(vec![
+            EmptyFile("amigos.txt"),
+            EmptyFile("arepas.clu"),
+            EmptyFile("los.txt"),
+            EmptyFile("tres.txt"),
+        ]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                ls
+                | get name
+                | find arep
+                | to json
+            "#
+        ));
+
+        assert_eq!(actual.out, r#""arepas.clu""#);
+    })
+}
+
+#[test]
+fn find_with_filepath_search_with_multiple_patterns() {
+    Playground::setup("filepath_test_2", |dirs, sandbox| {
+        sandbox.with_files(vec![
+            EmptyFile("amigos.txt"),
+            EmptyFile("arepas.clu"),
+            EmptyFile("los.txt"),
+            EmptyFile("tres.txt"),
+        ]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                ls
+                | get name
+                | find arep ami
+                | to json
+            "#
+        ));
+
+        assert_eq!(actual.out, r#"["amigos.txt","arepas.clu"]"#);
+    })
+}

crates/nu-command/tests/commands/mod.rs

@@ -14,6 +14,7 @@ mod echo;
 mod empty;
 mod enter;
 mod every;
+mod find;
 mod first;
 mod flatten;
 mod format;