Mathsqrt (#3239)

* Output error when ls into a file without permission

* math sqrt

* added test to check fails when ls into prohibited dir

* fix lint

* math sqrt with tests and doc

* trigger wasm build

* Update filesystem_shell.rs

* always forgetting the linting

* fix clippy complaining

Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>

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

@@ -2,6 +2,7 @@ mod avg;
 mod eval;
 mod median;
 mod round;
+mod sqrt;
 mod sum;
 
 use nu_test_support::{nu, pipeline};

crates/nu-command/tests/commands/math/sqrt.rs

@@ -0,0 +1,31 @@
+use nu_test_support::nu;
+
+#[test]
+fn can_sqrt_numbers() {
+    let actual = nu!(
+        cwd: ".",
+        "echo [0.25 2 4] | math sqrt | math sum"
+    );
+
+    assert_eq!(actual.out, "3.914213562373095048801688724209698078569671875376948073176679737990732478462107038850387534327641573");
+}
+
+#[test]
+fn can_sqrt_irrational() {
+    let actual = nu!(
+        cwd: ".",
+        "echo 2 | math sqrt"
+    );
+
+    assert_eq!(actual.out, "1.414213562373095048801688724209698078569671875376948073176679737990732478462107038850387534327641573");
+}
+
+#[test]
+fn can_sqrt_perfect_square() {
+    let actual = nu!(
+        cwd: ".",
+        "echo 4 | math sqrt"
+    );
+
+    assert_eq!(actual.out, "2");
+}