fix: add support for Decimal property values (#187)

* fix: add support for Decimal property values

* fixed lint warnings

Author: doctorcooper

Sources/Amplitude/Utilities/CodableExtension.swift

@@ -134,6 +134,8 @@ extension KeyedEncodingContainer {
                 try container.encodeIfPresent(val, forKey: JSONCodingKeys(stringValue: item.key)!)
             } else if let val = item.value as? CGFloat {
                 try container.encodeIfPresent(val, forKey: JSONCodingKeys(stringValue: item.key)!)
+            } else if let val = item.value as? Decimal {
+                try container.encodeIfPresent(val, forKey: JSONCodingKeys(stringValue: item.key)!)
             } else if let val = item.value as? Bool {
                 try container.encodeIfPresent(val, forKey: JSONCodingKeys(stringValue: item.key)!)
             } else if let val = item.value as? [Any] {

Tests/AmplitudeTests/Events/BaseEventTests.swift

@@ -31,7 +31,8 @@ final class BaseEventTests: XCTestCase {
                 "int64": 1 as Int64,
                 "int32": 1 as Int32,
                 "cgfloat": 3.14 as CGFloat,
-                "double": 3.14 as Double
+                "double": 3.14 as Double,
+                "decimal": 3.14 as Decimal
             ]
         )
 
@@ -62,6 +63,10 @@ final class BaseEventTests: XCTestCase {
             baseEventDict!["event_properties"]!["double" as NSString] as! Double,
             3.14
         )
+        XCTAssertEqual(
+            Decimal(baseEventDict!["event_properties"]!["decimal" as NSString] as! Double),
+            Decimal(3.14)
+        )
         XCTAssertEqual(
             baseEventDict!["event_properties"]!["string" as NSString] as! String,
             "stringValue"