Add compound plugins

Author: saspre

src/__tests__/compound-plugins.js

@@ -0,0 +1,163 @@
+/* @flow */
+import tape from 'tape-cup';
+import ClientAppFactory from '../client-app';
+import ServerAppFactory from '../server-app';
+import {createPlugin} from '../create-plugin';
+import {createToken, createArrayToken} from '../create-token';
+import type {FusionPlugin, Token, ArrayToken} from '../types.js';
+
+const App = __BROWSER__ ? ClientAppFactory() : ServerAppFactory();
+type DepsType = {
+  dep: string,
+};
+type AType = {
+  a: string,
+};
+
+const TokenA: ArrayToken<AType> = createArrayToken('TokenA');
+const TokenDep1: Token<DepsType> = createToken('TokenDep1');
+const TokenDep2: Token<DepsType> = createToken('TokenDep2');
+
+tape('compound tokens support dependencies', t => {
+  const app = new App('el', el => el);
+  t.ok(app, 'creates an app');
+  const counters = {
+    deps: 0,
+    a: 0,
+    b: 0,
+  };
+  const PluginDeps: FusionPlugin<{}, DepsType> = createPlugin({
+    provides: () => {
+      counters.deps++;
+      t.equal(counters.deps, 1, 'only instantiates once');
+      return {
+        dep: 'PluginDep',
+      };
+    },
+  });
+
+  const PluginA: FusionPlugin<void, AType> = createPlugin({
+    provides: () => {
+      counters.a++;
+      t.equal(counters.a, 1, 'only instantiates once');
+      return {
+        a: 'PluginA',
+      };
+    },
+  });
+
+  type PluginBType = FusionPlugin<{dep: Token<DepsType>}, AType>;
+  const PluginB: PluginBType = createPlugin({
+    deps: {dep: TokenDep1},
+    provides: deps => {
+      counters.b++;
+      t.equal(deps.dep.dep, 'PluginDep');
+      t.equal(counters.b, 1, 'only instantiates once');
+      return {
+        a: 'PluginB',
+      };
+    },
+  });
+
+  app.register(TokenA, PluginA);
+  app.register(TokenA, PluginB);
+  // $FlowFixMe
+  app.register(TokenA, 'value');
+  app.register(TokenDep1, PluginDeps);
+  app.register(
+    createPlugin({
+      deps: {a: TokenA},
+      provides: deps => {
+        t.equal(deps.a[0].a, 'PluginA');
+        t.equal(deps.a[1].a, 'PluginB');
+        t.equal(deps.a[2], 'value');
+      },
+    })
+  );
+  t.equal(counters.a, 0, 'does not instantiate until resolve is called');
+  t.equal(counters.b, 0, 'does not instantiate until resolve is called');
+  t.equal(counters.deps, 0, 'does not instantiate until resolve is called');
+  app.resolve();
+  t.equal(counters.a, 1, 'only instantiates once');
+  t.equal(counters.b, 1, 'only instantiates once');
+  t.equal(counters.deps, 1, 'only instantiates once');
+  t.end();
+});
+
+tape('dependency registration with aliases', t => {
+  const app = new App('el', el => el);
+  t.ok(app, 'creates an app');
+  const counters = {
+    dep1: 0,
+    dep2: 0,
+    a: 0,
+    b: 0,
+  };
+  const PluginDep1: FusionPlugin<{}, DepsType> = createPlugin({
+    provides: () => {
+      counters.dep1++;
+      t.equal(counters.dep1, 1, 'only instantiates once');
+      return {
+        dep: 'PluginDep1',
+      };
+    },
+  });
+  const PluginDep2: FusionPlugin<{}, DepsType> = createPlugin({
+    provides: () => {
+      counters.dep2++;
+      t.equal(counters.dep2, 1, 'only instantiates once');
+      return {
+        dep: 'PluginDep2',
+      };
+    },
+  });
+
+  const PluginA: FusionPlugin<{dep: Token<DepsType>}, AType> = createPlugin({
+    deps: {dep: TokenDep1},
+    provides: deps => {
+      counters.a++;
+      t.equal(deps.dep.dep, 'PluginDep2');
+      t.equal(counters.a, 1, 'only instantiates once');
+      return {
+        a: 'PluginA',
+      };
+    },
+  });
+
+  type PluginBType = FusionPlugin<{dep: Token<DepsType>}, AType>;
+  const PluginB: PluginBType = createPlugin({
+    deps: {dep: TokenDep1},
+    provides: deps => {
+      counters.b++;
+      t.equal(deps.dep.dep, 'PluginDep2');
+      t.equal(counters.b, 1, 'only instantiates once');
+      return {
+        a: 'PluginB',
+      };
+    },
+  });
+
+  app.register(TokenA, PluginA);
+  app.register(TokenA, PluginB).alias(TokenDep1, TokenDep2);
+  app.register(TokenDep1, PluginDep1);
+  app.register(TokenDep2, PluginDep2);
+  app.register(
+    createPlugin({
+      deps: {a: TokenA},
+      provides: deps => {
+        t.equal(deps.a[0].a, 'PluginA');
+        t.equal(deps.a[1].a, 'PluginB');
+      },
+    })
+  );
+  t.equal(counters.a, 0, 'does not instantiate until resolve is called');
+  t.equal(counters.b, 0, 'does not instantiate until resolve is called');
+  t.equal(counters.dep1, 0, 'does not instantiate until resolve is called');
+  t.equal(counters.dep2, 0, 'does not instantiate until resolve is called');
+  app.resolve();
+  t.equal(counters.a, 1, 'only instantiates once');
+  t.equal(counters.b, 1, 'only instantiates once');
+  t.equal(counters.dep1, 1, 'only instantiates once');
+  t.equal(counters.dep2, 1, 'only instantiates once');
+  t.end();
+});

src/base-app.js

@@ -68,12 +68,42 @@ class FusionApp {
     return this._register(token, value);
   }
   _register<TResolved>(token: Token<TResolved>, value: *) {
-    this.plugins.push(token);
-    const {aliases, enhancers} = this.registered.get(getTokenRef(token)) || {
+    const {value: registeredValue, aliases, enhancers} = this.registered.get(
+      getTokenRef(token)
+    ) || {
+      value: null,
       aliases: new Map(),
       enhancers: [],
     };
-    this.registered.set(getTokenRef(token), {value, aliases, enhancers, token});
+    if (token.isCompound) {
+      if (!registeredValue) {
+        // Initial value is set as an empty array
+        this.registered.set(getTokenRef(token), {
+          // $FlowFixMe
+          value: [],
+          aliases,
+          enhancers,
+          token,
+        });
+      }
+      this.enhance(token, originalValue => {
+        return createPlugin({
+          deps: {...value.deps},
+          provides: (...args) => {
+            value = value.provides ? value.provides(...args) : value;
+            return [...originalValue, value];
+          },
+        });
+      });
+    } else {
+      this.registered.set(getTokenRef(token), {
+        value,
+        aliases,
+        enhancers,
+        token,
+      });
+    }
+    this.plugins.push(token);
     function alias(sourceToken: *, destToken: *) {
       if (aliases) {
         aliases.set(sourceToken, destToken);
@@ -101,7 +131,12 @@ class FusionApp {
     if (enhancers && Array.isArray(enhancers)) {
       enhancers.push(enhancer);
     }
-    this.registered.set(getTokenRef(token), {value, aliases, enhancers, token});
+    this.registered.set(getTokenRef(token), {
+      value,
+      aliases,
+      enhancers,
+      token,
+    });
   }
   cleanup() {
     return Promise.all(this.cleanups.map(fn => fn()));

src/base-app.js.flow

@@ -13,6 +13,7 @@ import type {
   FusionPlugin,
   Middleware,
   Token,
+  ArrayToken,
 } from './types.js';
 
 declare class FusionApp {
@@ -26,11 +27,16 @@ declare class FusionApp {
   register<TDeps, TProvides>(
     Plugin: FusionPlugin<TDeps, TProvides>
   ): aliaser<Token<*>>;
+  register<TVal, TDeps>(
+    token: ArrayToken<TVal>,
+    Plugin: FusionPlugin<TDeps, TVal>
+  ): aliaser<Token<*>>;
   register<TVal, TDeps>(
     token: Token<TVal>,
     Plugin: FusionPlugin<TDeps, TVal>
   ): aliaser<Token<*>>;
   register<TVal>(token: Token<TVal>, val: TVal): aliaser<Token<*>>;
+  register<TVal>(token: ArrayToken<TVal>, val: TVal): aliaser<Token<*>>;
   middleware<TDeps>(
     deps: TDeps,
     middleware: (Deps: $ObjMap<TDeps, ExtractReturnType>) => Middleware

src/create-token.js

@@ -6,7 +6,7 @@
  * @flow
  */
 
-import type {Token} from './types.js';
+import type {Token, ArrayToken} from './types.js';
 
 export const TokenType = {
   Required: 0,
@@ -18,6 +18,7 @@ export class TokenImpl<TResolved> {
   ref: mixed;
   type: $Values<typeof TokenType>;
   optional: ?TokenImpl<TResolved>;
+  isCompound = false;
 
   constructor(name: string, ref: mixed) {
     this.name = name;
@@ -33,3 +34,12 @@ export function createToken<TResolvedType>(name: string): Token<TResolvedType> {
   // $FlowFixMe
   return new TokenImpl(name);
 }
+
+export function createArrayToken<TResolvedType>(
+  name: string
+): ArrayToken<TResolvedType> {
+  const token = new TokenImpl(name);
+  token.isCompound = true;
+  // $FlowFixMe
+  return token;
+}

src/index.js

@@ -41,7 +41,7 @@ export {
   HttpServerToken,
 } from './tokens';
 export {createPlugin} from './create-plugin';
-export {createToken} from './create-token';
+export {createToken, createArrayToken} from './create-token';
 export {getEnv};
 
 type FusionApp = typeof BaseApp;

src/types.js

@@ -11,6 +11,14 @@ import type {Context as KoaContext} from 'koa';
 export type Token<T> = {
   (): T,
   optional: () => void | T,
+  isCompound: false,
+};
+
+export type ArrayToken<T> = {
+  (): T,
+} & {
+  ...Token<Array<T>>,
+  isCompound: true,
 };
 
 type ExtendedKoaContext = KoaContext & {memoized: Map<Object, mixed>};