Add assertEqual function to KCL stdlib (#3279)

Takes a tolerance, because floating-point imprecision.

src/wasm-lib/kcl/src/std/assert.rs

@@ -67,6 +67,27 @@ pub async fn assert_gt(args: Args) -> Result<MemoryItem, KclError> {
     args.make_null_user_val()
 }
 
+/// Check that a numerical value equals another at runtime,
+/// otherwise raise an error.
+///
+/// ```no_run
+/// let n = 1.0285
+/// let m = 1.0286
+/// assertEqual(n, m, 0.01, "n is within the given tolerance for m")
+/// ```
+#[stdlib {
+    name = "assertEqual",
+}]
+async fn inner_assert_equal(left: f64, right: f64, epsilon: f64, message: &str, args: &Args) -> Result<(), KclError> {
+    _assert((right - left).abs() < epsilon, message, args).await
+}
+
+pub async fn assert_equal(args: Args) -> Result<MemoryItem, KclError> {
+    let (left, right, epsilon, description): (f64, f64, f64, String) = args.get_data()?;
+    inner_assert_equal(left, right, epsilon, &description, &args).await?;
+    args.make_null_user_val()
+}
+
 /// Check that a numerical value is greater than another at runtime,
 /// otherwise raise an error.
 ///

src/wasm-lib/kcl/src/std/mod.rs

@@ -120,6 +120,7 @@ lazy_static! {
         Box::new(crate::std::math::ToRadians),
         Box::new(crate::std::polar::Polar),
         Box::new(crate::std::assert::Assert),
+        Box::new(crate::std::assert::AssertEqual),
         Box::new(crate::std::assert::AssertLessThan),
         Box::new(crate::std::assert::AssertGreaterThan),
         Box::new(crate::std::assert::AssertLessThanOrEq),

src/wasm-lib/tests/executor/inputs/computed_var.kcl

@@ -4,8 +4,7 @@ const arr = [0, 0, 0, 10]
 const i = 3
 const ten = arr[i]
 
-assertLessThanOrEq(ten, 10, "oops")
-assertGreaterThanOrEq(ten, 10, "oops2")
+assertEqual(ten, 10, 0.000001, "oops")
 
 const p = "foo"
 const obj = {
@@ -14,5 +13,4 @@ const obj = {
 }
 const one = obj[p]
 
-assertLessThanOrEq(one, 1, "oops")
-assertGreaterThanOrEq(one, 1, "oops2")
+assertEqual(one, 1, 0.0000001, "oops")