Introduce DevicePlugin APIs

Summary:
This stack introduces Sandy device plugins, they are quite similar to normal plugins, but, a devicePlugin module is organized as

```
export function supportsDevice(device): boolean

export function devicePlugin(devicePluginClient)

export function Component
```

Device plugins get access to the device meta data and can subscribe to the `onLogEntry` callback and `onDestroy` lifecycle.

They will be able to store state just as normal plugins, but can't send or receive methods, so devicePluginClient is a bit limited.

This diff only sets up most of the new data structures, and makes sure everything still compiles and no existing tests fail.

To prevent this diff from becoming to big, actually loading, rendering and testing device plugins will be done in next diffs

Please take a critical look at the api proposed and the (especially) the public names used :)

Reviewed By: passy, nikoant

Differential Revision: D22691351

fbshipit-source-id: bdbbd7f86d14b646fc9a693ad19f33583a76f26d

desktop/flipper-plugin/src/plugin/SandyPluginDefinition.tsx

@@ -8,20 +8,29 @@
  */
 
 import {PluginDetails} from 'flipper-plugin-lib';
-import {FlipperPluginFactory, FlipperPluginComponent} from './Plugin';
+import {PluginFactory, FlipperPluginComponent} from './Plugin';
+import {DevicePluginPredicate, DevicePluginFactory} from './DevicePlugin';
 
 /**
  * FlipperPluginModule describe the exports that are provided by a typical Flipper Desktop plugin
  */
-export type FlipperPluginModule<
-  Factory extends FlipperPluginFactory<any, any>
-> = {
+export type FlipperDevicePluginModule = {
+  /** predicate that determines if this plugin applies to the currently selcted device */
+  supportsDevice: DevicePluginPredicate;
+  /** the factory function that initializes a plugin instance */
+  devicePlugin: DevicePluginFactory;
+  /** the component type that can render this plugin */
+  Component: FlipperPluginComponent;
+};
+
+/**
+ * FlipperPluginModule describe the exports that are provided by a typical Flipper Desktop plugin
+ */
+export type FlipperPluginModule<Factory extends PluginFactory<any, any>> = {
   /** the factory function that initializes a plugin instance */
   plugin: Factory;
   /** the component type that can render this plugin */
   Component: FlipperPluginComponent;
-  // TODO: support device plugins T68738317
-  // devicePlugin: FlipperPluginFactory
 };
 
 /**
@@ -32,8 +41,9 @@ export type FlipperPluginModule<
  */
 export class SandyPluginDefinition {
   id: string;
-  module: FlipperPluginModule<any>;
+  module: FlipperPluginModule<any> | FlipperDevicePluginModule;
   details: PluginDetails;
+  isDevicePlugin: boolean;
 
   // TODO: Implement T68683476
   exportPersistedState:
@@ -47,13 +57,28 @@ export class SandyPluginDefinition {
       ) => Promise<any /* TODO: StaticPersistedState | undefined */>)
     | undefined = undefined;
 
-  constructor(details: PluginDetails, module: FlipperPluginModule<any>) {
+  constructor(
+    details: PluginDetails,
+    module: FlipperPluginModule<any> | FlipperDevicePluginModule,
+  );
+  constructor(details: PluginDetails, module: any) {
     this.id = details.id;
     this.details = details;
-    if (!module.plugin || typeof module.plugin !== 'function') {
-      throw new Error(
-        `Flipper plugin '${this.id}' should export named function called 'plugin'`,
-      );
+    if (module.supportsDevice) {
+      // device plugin
+      this.isDevicePlugin = true;
+      if (!module.devicePlugin || typeof module.devicePlugin !== 'function') {
+        throw new Error(
+          `Flipper device plugin '${this.id}' should export named function called 'devicePlugin'`,
+        );
+      }
+    } else {
+      this.isDevicePlugin = false;
+      if (!module.plugin || typeof module.plugin !== 'function') {
+        throw new Error(
+          `Flipper plugin '${this.id}' should export named function called 'plugin'`,
+        );
+      }
     }
     if (!module.Component || typeof module.Component !== 'function') {
       throw new Error(
@@ -64,6 +89,16 @@ export class SandyPluginDefinition {
     this.module.Component.displayName = `FlipperPlugin(${this.id})`;
   }
 
+  asDevicePluginModule(): FlipperDevicePluginModule {
+    if (!this.isDevicePlugin) throw new Error('Not a device plugin');
+    return this.module as FlipperDevicePluginModule;
+  }
+
+  asPluginModule(): FlipperPluginModule<any> {
+    if (this.isDevicePlugin) throw new Error('Not an application plugin');
+    return this.module as FlipperPluginModule<any>;
+  }
+
   get packageName() {
     return this.details.name;
   }