ci(audience): run Unity-dependent SDK tests via dedicated workflow (SDK-326)

The Unity-dependent test asmdefs in the Audience package were never
discovered by CI: test-audience-sdk.yml runs dotnet test (csproj excludes
Tests/Runtime/Unity/** + Tests/Editor/**), and test-audience-sample-app.yml
runs Unity Test Runner against examples/audience but the project's
manifest.json had no testables entry, so Immutable.Audience.Runtime.Tests
was never compiled by Unity. As a result DeviceCollectorTests shipped with
two compile errors (missing InternalsVisibleTo + a broken 'is not string s'
pattern) that no PR caught.

Closes the gap with:

* New test-audience-sdk-unity.yml — single GameCI Linux cell, Unity 2022.3
  with iOS module so UnityEditor.iOS.Xcode + UNITY_IOS resolve. Single cell
  on purpose; these tests don't vary by Unity LTS / backend / OS.
* testables entry in examples/audience/Packages/manifest.json so Unity Test
  Runner discovers the package's test asmdefs.
* InternalsVisibleTo on Immutable.Audience.Unity for the test asmdef so
  DeviceCollectorTests can see internal types.
* Fix the 'is not string s' pattern: the negated form doesn't bind s, so
  CS0165 fired on s.Length once compilation actually ran.

Author: nattb8

.github/workflows/test-audience-sdk-unity.yml

@@ -0,0 +1,76 @@
+name: Audience package — Unity Tests
+
+# Sibling to test-audience-sdk.yml. That workflow runs pure-C# unit tests via
+# `dotnet test` on Ubuntu (~1 min) but its csproj excludes anything that
+# references UnityEngine/UnityEditor/UnityEditor.iOS.Xcode. This workflow picks
+# up exactly the tests that get excluded — DeviceCollector / IDFVBridge /
+# InstallReferrerBridge / iOSInfoPlistPostProcessor — by booting Unity Test
+# Runner against the sample app project.
+#
+# Single matrix cell on purpose: these tests exercise platform-agnostic SDK
+# logic that happens to use Unity types. They don't vary across Unity LTS,
+# scripting backend, or OS, so spending a multi-cell matrix on them would
+# burn CI minutes for zero added signal. The cross-version IL2CPP build
+# matrix lives in test-audience-sample-app.yml.
+#
+# iOS targetPlatform is non-negotiable: the iOSInfoPlistPostProcessor tests
+# reference UnityEditor.iOS.Xcode (Apple's PlistDocument API) which only ships
+# in the iOS GameCI image. Without it the test asmdef silently fails to
+# compile — which is the exact CI gap this workflow is here to close.
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'src/Packages/Audience/**'
+      - 'examples/audience/Packages/manifest.json'
+      - '.github/workflows/test-audience-sdk-unity.yml'
+  pull_request:
+    paths:
+      - 'src/Packages/Audience/**'
+      - 'examples/audience/Packages/manifest.json'
+      - '.github/workflows/test-audience-sdk-unity.yml'
+
+jobs:
+  editmode:
+    if: github.event.pull_request.head.repo.fork == false || github.event_name == 'workflow_dispatch'
+    name: EditMode (Unity 2022.3 / iOS module)
+    runs-on: ubuntu-latest-8-cores
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          lfs: true
+
+      - uses: actions/cache@v4
+        with:
+          path: examples/audience/Library
+          key: Library-audience-unity-tests-${{ hashFiles('examples/audience/Packages/**', 'examples/audience/ProjectSettings/**', 'src/Packages/Audience/**') }}
+          restore-keys: |
+            Library-audience-unity-tests-
+
+      - uses: game-ci/unity-test-runner@v4
+        env:
+          UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
+          UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
+          UNITY_SERIAL: ${{ secrets.UNITY_SERIAL }}
+        with:
+          # Pinned to the same Unity version the mobile-build matrix uses so
+          # the GameCI image is shared across workflows (less cache churn).
+          unityVersion: 2022.3.62f2
+          # iOS image needed for UnityEditor.iOS.Xcode + UNITY_IOS define.
+          targetPlatform: iOS
+          projectPath: examples/audience
+          testMode: editmode
+          # Limit test discovery to the Audience package's own asmdefs. The
+          # sample app's PlayMode integration tests run in
+          # test-audience-sample-app.yml; running them here would duplicate.
+          customParameters: -assemblyNames Immutable.Audience.Runtime.Tests;Immutable.Audience.Editor.Tests
+          checkName: Audience EditMode Tests
+          artifactsPath: artifacts
+
+      - uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: audience-unity-test-results
+          path: artifacts

examples/audience/Packages/manifest.json

@@ -37,5 +37,8 @@
     "com.unity.modules.vr": "1.0.0",
     "com.unity.modules.wind": "1.0.0",
     "com.unity.modules.xr": "1.0.0"
-  }
+  },
+  "testables": [
+    "com.immutable.audience"
+  ]
 }

src/Packages/Audience/Runtime/Unity/AssemblyInfo.cs

@@ -0,0 +1,3 @@
+using System.Runtime.CompilerServices;
+
+[assembly: InternalsVisibleTo("Immutable.Audience.Runtime.Tests")]

src/Packages/Audience/Runtime/Unity/AssemblyInfo.cs.meta

@@ -68,7 +68,8 @@ public void CollectGameLaunchProperties_StringFields_DoNotExceed256Chars()
                 "platform", "version", "buildGuid", "unityVersion",
                 "osFamily", "deviceModel", "gpu", "gpuVendor", "cpu" })
             {
-                if (!props.TryGetValue(key, out var val) || val is not string s) continue;
+                if (!props.TryGetValue(key, out var val)) continue;
+                if (val is not string s) continue;
                 Assert.LessOrEqual(s.Length, 256, $"props[{key}] exceeds 256 chars");
             }
         }