From 5a0f83695c6a750686c0b3d8f257d21d585a1a79 Mon Sep 17 00:00:00 2001
From: "Christoph J. Scherr" <Christoph.Scherr@newtec.de>
Date: Thu, 25 Jan 2024 10:10:10 +0100
Subject: [PATCH] documenting the revsqrt tests a little more

---
 members/revsqrt/Cargo.toml             |  4 ++
 members/revsqrt/tests/basic-revsqrt.rs | 71 ++++++++++++++++++++++++++
 members/revsqrt/tests/revsqrt.rs       | 17 +++---
 3 files changed, 83 insertions(+), 9 deletions(-)
 create mode 100644 members/revsqrt/tests/basic-revsqrt.rs

diff --git a/members/revsqrt/Cargo.toml b/members/revsqrt/Cargo.toml
index c1072c7..b654fb9 100644
--- a/members/revsqrt/Cargo.toml
+++ b/members/revsqrt/Cargo.toml
@@ -25,3 +25,7 @@ path = "src/main.rs"
 [[test]]
 name = "revsqrt"
 harness = false  # allows Cucumber to print output instead of libtest
+
+[[test]]
+name = "basic-revsqrt"
+harness = true
diff --git a/members/revsqrt/tests/basic-revsqrt.rs b/members/revsqrt/tests/basic-revsqrt.rs
new file mode 100644
index 0000000..23a511a
--- /dev/null
+++ b/members/revsqrt/tests/basic-revsqrt.rs
@@ -0,0 +1,71 @@
+use std::iter::zip;
+
+use revsqrt;
+
+use rand;
+
+// is n about the same as m?
+// This is actually not so easy! How do you measure "about same"ness?
+// Also, it is not transitive, as 1 ≈ 1.1 ≈ 1.2 ≈ 1.3 ≈ ... ≈ 2 ≈ ... ≈ 3 ≈ ... ≈ infinity, that's
+// a thought of me at least?
+#[inline]
+fn about_same(n: f32, m: f32) -> bool {
+    // dbg!((n, m));
+    // dbg!((n - m).abs());
+    // dbg!(calc_gate(n, m));
+    // dbg!((n - m).abs() < calc_gate(n, m));
+    (n - m).abs() <= calc_gate(n, m)
+}
+
+#[inline]
+fn calc_gate(n: f32, m: f32) -> f32 {
+    0.01 + ((n.abs().sqrt().min(m.abs().sqrt())).abs() / 10f32)
+}
+
+#[test]
+fn test_calc_fast_rsqrt() {
+    assert_ne!(0.0, revsqrt::fast_inverse_sqrt(rand::random()))
+}
+
+#[test]
+fn test_calc_regular_rsqrt() {
+    assert_ne!(0.0, revsqrt::regular_inverse_sqrt(rand::random()))
+}
+
+#[test]
+fn test_calc_specific_fast_rsqrt() {
+    let params: &[f32] = &[1.0, 1.1, 100.0, 1337.0, 123.45678900, 1337.1337];
+    let results: &[f32] = &[
+        1.0,
+        0.9534625892455922,
+        0.1,
+        0.02734854943722097,
+        0.0900000004095,
+        0.027347182112297627,
+    ];
+    for (n, m) in zip(params, results) {
+        assert!(about_same(revsqrt::fast_inverse_sqrt(*n), *m))
+    }
+}
+
+#[test]
+fn test_calc_specific_reqular_rsqrt() {
+    let params: &[f32] = &[1.0, 1.1, 100.0, 1337.0, 123.45678900, 1337.1337];
+    let results: &[f32] = &[
+        1.0,
+        0.9534625892455922,
+        0.1,
+        0.02734854943722097,
+        0.0900000004095,
+        0.027347182112297627,
+    ];
+    for (n, m) in zip(params, results) {
+        assert_eq!(revsqrt::regular_inverse_sqrt(*n), *m)
+    }
+}
+
+#[test]
+fn test_fail() {
+    println!("the stdout will be printed on fail!");
+    assert!(false)
+}
diff --git a/members/revsqrt/tests/revsqrt.rs b/members/revsqrt/tests/revsqrt.rs
index 56e8fe0..f7e2260 100644
--- a/members/revsqrt/tests/revsqrt.rs
+++ b/members/revsqrt/tests/revsqrt.rs
@@ -1,23 +1,22 @@
 use std::iter::zip;
 
+use revsqrt;
+
 use cucumber::{gherkin::Step, given, then, when, World};
 use rand;
 
+/// stores the current information for each scenario
 #[derive(Debug, Default, World)]
-pub struct NumWorld {
+struct NumWorld {
     numbers: Vec<(f32, f32)>,
 }
 
-// is n about the same as m?
-// This is actually not so easy! How do you measure "about same"ness?
-// Also, it is not transitive, as 1 ≈ 1.1 ≈ 1.2 ≈ 1.3 ≈ ... ≈ 2 ≈ ... ≈ 3 ≈ ... ≈ infinity, that's
-// a thought of me at least?
+/// is n about the same as m?
+///
+/// This is actually not so easy! How do you measure *about same*ness?
+/// Also, I don't think it is transitive, as 1 ≈ 1.1 ≈ 1.2 ≈ 1.3 ≈ ... ≈ 2 ≈ ... ≈ 3 ≈ ... ≈ infinity
 #[inline]
 fn about_same(n: f32, m: f32) -> bool {
-    // dbg!((n, m));
-    // dbg!((n - m).abs());
-    // dbg!(calc_gate(n, m));
-    // dbg!((n - m).abs() < calc_gate(n, m));
     (n - m).abs() <= calc_gate(n, m)
 }