From ff0fc3df89aaab06d559f067cb898ebc896280e9 Mon Sep 17 00:00:00 2001
From: Jan-Erik Rediger <jrediger@mozilla.com>
Date: Wed, 29 Oct 2025 11:59:17 +0100
Subject: [PATCH] Swift: Decode object metric dataa from its snake case JSON
 form

---
 .../ios/Glean/Metrics/ObjectMetric.swift      |  1 +
 .../Metrics/ObjectMetricTests.swift           | 34 +++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/glean-core/ios/Glean/Metrics/ObjectMetric.swift b/glean-core/ios/Glean/Metrics/ObjectMetric.swift
index 4cdb44c613..676153afdd 100644
--- a/glean-core/ios/Glean/Metrics/ObjectMetric.swift
+++ b/glean-core/ios/Glean/Metrics/ObjectMetric.swift
@@ -81,6 +81,7 @@ public final class ObjectMetricType<K: ObjectSerialize>: Sendable {
     public func testGetValue(_ pingName: String? = nil) -> K? {
         guard let data = self.inner.testGetValue(pingName) else { return nil }
         let jsonDecoder = JSONDecoder()
+        jsonDecoder.keyDecodingStrategy = .convertFromSnakeCase
         return try! jsonDecoder.decode(K.self, from: Data(data.utf8))
     }
 
diff --git a/glean-core/ios/GleanTests/Metrics/ObjectMetricTests.swift b/glean-core/ios/GleanTests/Metrics/ObjectMetricTests.swift
index 5eeac99ed9..388f2dc95d 100644
--- a/glean-core/ios/GleanTests/Metrics/ObjectMetricTests.swift
+++ b/glean-core/ios/GleanTests/Metrics/ObjectMetricTests.swift
@@ -8,6 +8,7 @@ import XCTest
 struct BalloonsObjectItem: Decodable, Equatable, ObjectSerialize {
     var colour: String?
     var diameter: Int64?
+    var anotherValue: Bool?
 
     func intoSerializedObject() -> String {
         var data: [String] = []
@@ -21,6 +22,11 @@ struct BalloonsObjectItem: Decodable, Equatable, ObjectSerialize {
             elem.append(val.intoSerializedObject())
             data.append(elem)
         }
+        if let val = self.anotherValue {
+            var elem = "\"another_value\":"
+            elem.append(val.intoSerializedObject())
+            data.append(elem)
+        }
         let obj = data.joined(separator: ",")
         let json = "{" + obj + "}"
         return json
@@ -132,4 +138,32 @@ class ObjectMetricTypeTests: XCTestCase {
         XCTAssertEqual(2, snapshot.count)
         XCTAssertEqual(expected, snapshot)
     }
+
+    func testObjectDecodesFromSnakeCase() {
+        let metric = ObjectMetricType<BalloonsObject>(CommonMetricData(
+            category: "test",
+            name: "balloon",
+            sendInPings: ["store1"],
+            lifetime: .ping,
+            disabled: false
+        ))
+
+        XCTAssertNil(metric.testGetValue())
+
+        var balloons: BalloonsObject = []
+        balloons.append(BalloonsObjectItem(colour: "red", diameter: 5, anotherValue: true))
+        balloons.append(BalloonsObjectItem(colour: "green", anotherValue: false))
+        metric.set(balloons)
+
+        let snapshot = metric.testGetValue()!
+        XCTAssertNotNil(snapshot)
+        XCTAssertEqual(2, snapshot.count)
+
+        XCTAssertEqual(snapshot[0].colour, "red")
+        XCTAssertEqual(snapshot[0].diameter, 5)
+        XCTAssertEqual(snapshot[0].anotherValue, true)
+        XCTAssertEqual(snapshot[1].colour, "green")
+        XCTAssertNil(snapshot[1].diameter)
+        XCTAssertEqual(snapshot[1].anotherValue, false)
+    }
 }