test-js: Use prettier and format all files

Author: https://github.com/mattco98
Commit: 6d58c48c2f
Pull-request: https://github.com/SerenityOS/serenity/pull/2689
Reviewed-by: https://github.com/linusg

Libraries/LibJS/Tests/builtins/NaN/NaN.js

@@ -1,13 +1,13 @@
 test("basic functionality", () => {
-    const nan = undefined + 1;
+  const nan = undefined + 1;
 
-    expect(nan + "").toBe("NaN");
-    expect(NaN + "").toBe("NaN");
-    expect(nan !== nan).toBeTrue();
-    expect(NaN !== NaN).toBeTrue();
-    expect(nan).toBeNaN();
-    expect(NaN).toBeNaN();
-    expect(0).not.toBeNaN();
-    expect(!!nan).toBeFalse();
-    expect(!!NaN).toBeFalse();
+  expect(nan + "").toBe("NaN");
+  expect(NaN + "").toBe("NaN");
+  expect(nan !== nan).toBeTrue();
+  expect(NaN !== NaN).toBeTrue();
+  expect(nan).toBeNaN();
+  expect(NaN).toBeNaN();
+  expect(0).not.toBeNaN();
+  expect(!!nan).toBeFalse();
+  expect(!!NaN).toBeFalse();
 });