From c88c52ebed6c9dda3b514ca6b6d65168de51042b Mon Sep 17 00:00:00 2001
From: Aditi Khare <aditi.khare@mongodb.com>
Date: Tue, 12 Nov 2024 18:39:58 -0500
Subject: [PATCH] casted

---
 docs/schematypes.md |  1 -
 lib/cast/double.js  | 52 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 lib/cast/double.js

diff --git a/docs/schematypes.md b/docs/schematypes.md
index e9e1281a16e..c6cdd386f3c 100644
--- a/docs/schematypes.md
+++ b/docs/schematypes.md
@@ -682,7 +682,6 @@ The values `null` and `undefined` are not cast.
 The following inputs will result will all result in a [CastError](validation.html#cast-errors) once validated, meaning that it will not throw on initialization, only when validated:
 
 * strings that do not represent a numeric string, a NaN or a null-ish value
-* numbers in non-decimal or exponential format
 * objects that don't have a `valueOf()` function
 * an input that represents a value outside the bounds of a IEEE 754-2008 floating point
 
diff --git a/lib/cast/double.js b/lib/cast/double.js
new file mode 100644
index 00000000000..9d4315c3503
--- /dev/null
+++ b/lib/cast/double.js
@@ -0,0 +1,52 @@
+'use strict';
+
+const assert = require('assert');
+const BSON = require('bson');
+
+/**
+ * Given a value, cast it to a IEEE 754-2008 floating point, or throw an `Error` if the value
+ * cannot be casted. `null`, `undefined`, and `NaN` are considered valid inputs.
+ *
+ * @param {Any} value
+ * @return {Number}
+ * @throws {Error} if `value` does not represent a IEEE 754-2008 floating point. If casting from a string, see BSON Double.fromString API documentation
+ * @api private
+ */
+
+module.exports = function castDouble(val) {
+  if (val == null) {
+    return val;
+  }
+  if (val === '') {
+    return null;
+  }
+
+  let coercedVal;
+  if (val instanceof BSON.Int32 || val instanceof BSON.Double) {
+    coercedVal = val.value;
+  } else if (val instanceof BSON.Long) {
+    coercedVal = val.toNumber();
+  } else if (typeof val === 'string') {
+    try {
+      coercedVal = BSON.Double.fromString(val);
+    } catch {
+      assert.ok(false);
+    }
+  } else if (typeof val === 'object') {
+    const tempVal = val.valueOf() ?? val.toString();
+    // ex: { a: 'im an object, valueOf: () => 'helloworld' } // throw an error
+    if (typeof tempVal === 'string') {
+      try {
+        coercedVal = BSON.Double.fromString(val);
+      } catch {
+        assert.ok(false);
+      }
+    } else {
+      coercedVal = Number(tempVal);
+    }
+  } {
+    coercedVal = Number(val);
+  }
+
+  return coercedVal;
+};