feat(Discord): Add Plugin loader patch

src/main/kotlin/app/revanced/patches/discord/misc/plugin/PluginLoaderPatch.kt

@@ -0,0 +1,13 @@
+package app.revanced.patches.discord.misc.plugin
+
+import app.revanced.patches.discord.misc.plugin.fingerprints.MainActivityOnCreateFingerprint
+import app.revanced.patches.shared.misc.react.BaseReactPreloadScriptBootstrapperPatch
+
+@Suppress("unused")
+object PluginLoaderPatch : BaseReactPreloadScriptBootstrapperPatch(
+    name = "Plugin loader",
+    description = "Bootstraps a plugin loader.",
+    mainActivityOnCreateFingerprintInsertIndexPair = MainActivityOnCreateFingerprint to 2,
+) {
+    override val integrationsClassDescriptor = "Lapp/revanced/integrations/discord/plugin/BunnyBootstrapperPatch;"
+}

src/main/kotlin/app/revanced/patches/discord/misc/plugin/fingerprints/MainActivityOnCreateFingerprint.kt

@@ -0,0 +1,7 @@
+package app.revanced.patches.discord.misc.plugin.fingerprints
+
+import app.revanced.patcher.fingerprint.MethodFingerprint
+
+internal object MainActivityOnCreateFingerprint : MethodFingerprint(
+    customFingerprint = { method, classDef -> method.name == "onCreate" && classDef.endsWith("ReactActivity;") },
+)

src/main/kotlin/app/revanced/patches/shared/misc/react/BaseReactPreloadScriptBootstrapperPatch.kt

@@ -0,0 +1,63 @@
+package app.revanced.patches.shared.misc.react
+
+import app.revanced.patcher.PatchClass
+import app.revanced.patcher.data.BytecodeContext
+import app.revanced.patcher.extensions.InstructionExtensions.addInstructions
+import app.revanced.patcher.fingerprint.MethodFingerprint
+import app.revanced.patcher.patch.BytecodePatch
+import app.revanced.patcher.util.proxy.mutableTypes.MutableMethod.Companion.toMutable
+import app.revanced.patches.shared.misc.react.fingerprints.LoadScriptFromAssetFingerprint
+import app.revanced.patches.shared.misc.react.fingerprints.LoadScriptFromFileFingerprint
+import app.revanced.util.resultOrThrow
+
+abstract class BaseReactPreloadScriptBootstrapperPatch(
+    name: String? = null,
+    description: String? = null,
+    compatiblePackages: Set<CompatiblePackage>? = null,
+    dependencies: Set<PatchClass>? = null,
+    use: Boolean = true,
+    fingerprints: Set<MethodFingerprint> = emptySet(),
+    private val mainActivityOnCreateFingerprintInsertIndexPair: Pair<MethodFingerprint, Int>,
+) : BytecodePatch(
+    name = name,
+    description = description,
+    compatiblePackages = compatiblePackages,
+    dependencies = dependencies,
+    use = use,
+    requiresIntegrations = true,
+    fingerprints = setOf(
+        LoadScriptFromAssetFingerprint,
+        LoadScriptFromFileFingerprint,
+        mainActivityOnCreateFingerprintInsertIndexPair.first,
+    ) + fingerprints,
+) {
+    abstract val integrationsClassDescriptor: String
+
+    override fun execute(context: BytecodeContext) {
+        val (mainActivityOnCreateFingerprint, insertIndex) = mainActivityOnCreateFingerprintInsertIndexPair
+        val loadScriptFromAssetMethod = LoadScriptFromAssetFingerprint.resultOrThrow().mutableMethod
+        val (catalystInstanceImplClassDef, loadScriptFromFileMethod) = LoadScriptFromFileFingerprint.resultOrThrow()
+            .let { it.mutableClass to it.mutableMethod }
+
+        // Create preload script on main activity creation.
+        mainActivityOnCreateFingerprint.resultOrThrow().mutableMethod.addInstructions(
+            insertIndex, // Skip super call.
+            "invoke-static { p0 }, " +
+                "$integrationsClassDescriptor->startWritePreloadScripts(Landroid/app/Activity;)V",
+        )
+
+        // Copy of loadScriptFromFile method acts as a preload script loader.
+        loadScriptFromFileMethod.toMutable().apply {
+            name = "loadPreloadScriptFromFile"
+        }.let(catalystInstanceImplClassDef.methods::add)
+
+        // Load preload script.
+        listOf(loadScriptFromFileMethod, loadScriptFromAssetMethod).forEach { loadScriptMethod ->
+            loadScriptMethod.addInstructions(
+                0,
+                "invoke-virtual { p0 }, $integrationsClassDescriptor->" +
+                    "hookLoadScriptFromFile($catalystInstanceImplClassDef)V",
+            )
+        }
+    }
+}

src/main/kotlin/app/revanced/patches/shared/misc/react/fingerprints/CatalystInstanceImplFingerprint.kt

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+package app.revanced.patches.shared.misc.react.fingerprints
+
+import app.revanced.patcher.fingerprint.MethodFingerprint
+
+internal abstract class CatalystInstanceImplFingerprint(methodName: String) :
+    MethodFingerprint(
+        customFingerprint = { method, classDef ->
+            method.name == methodName && classDef.endsWith("CatalystInstanceImpl;")
+        },
+    )

src/main/kotlin/app/revanced/patches/shared/misc/react/fingerprints/LoadScriptFromAssetFingerprint.kt

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+package app.revanced.patches.shared.misc.react.fingerprints
+
+internal object LoadScriptFromAssetFingerprint : CatalystInstanceImplFingerprint("loadScriptFromAsset")

src/main/kotlin/app/revanced/patches/shared/misc/react/fingerprints/LoadScriptFromFileFingerprint.kt

@@ -0,0 +1,3 @@
+package app.revanced.patches.shared.misc.react.fingerprints
+
+internal object LoadScriptFromFileFingerprint : CatalystInstanceImplFingerprint("loadScriptFromFile")