introducing the find command (#3971)

* introducing the `find` command

* added tests

* merged main to accomodate "rest" changes

* test fix

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;