feat: allow enableIf to accept a funciton (#888)

.changeset/tame-dingos-invite.md

@@ -0,0 +1,5 @@
+---
+'@envelop/core': minor
+---
+
+Allow functions returning a plugin in `enableIf` and lazy load plugin by avoiding running the init flow of plugin if value is false.

packages/core/src/enable-if.ts

@@ -16,6 +16,10 @@ export function isPluginEnabled(t: PluginOrDisabledPlugin): t is Plugin {
 /**
  * Utility function to enable a plugin.
  */
-export function enableIf(condition: boolean, plugin: Plugin): PluginOrDisabledPlugin {
-  return condition ? plugin : EnableIfBranded.DisabledPlugin;
+export function enableIf(condition: boolean, plugin: Plugin | (() => Plugin)): PluginOrDisabledPlugin {
+  if (condition) {
+    return typeof plugin === 'function' ? plugin() : plugin;
+  } else {
+    return EnableIfBranded.DisabledPlugin;
+  }
 }

packages/core/test/utils.spec.ts

@@ -1,6 +1,8 @@
 import { useLogger, enableIf } from '@envelop/core';
+import { createTestkit, createSpiedPlugin } from '@envelop/testing';
 import { getIntrospectionQuery, parse } from 'graphql';
 import { isIntrospectionDocument } from '../src/utils';
+import { query, schema } from './common';
 
 describe('Utils', () => {
   describe('isIntrospectionDocument', () => {
@@ -39,5 +41,19 @@ describe('Utils', () => {
       const plugin = enableIf(false, useLogger());
       expect(plugin).toBeFalsy();
     });
+
+    it('Should not init plugin', async () => {
+      const spiedPlugin = createSpiedPlugin();
+      const testkit = createTestkit([enableIf(false, spiedPlugin.plugin)], schema);
+      await testkit.execute(query);
+      expect(spiedPlugin.spies.beforeExecute).not.toHaveBeenCalled();
+    });
+
+    it('Should init plugin', async () => {
+      const spiedPlugin = createSpiedPlugin();
+      const testkit = createTestkit([enableIf(true, spiedPlugin.plugin)], schema);
+      await testkit.execute(query);
+      expect(spiedPlugin.spies.beforeExecute).toHaveBeenCalled();
+    });
   });
 });

website/docs/core.md

@@ -208,6 +208,8 @@ const getEnveloped = envelop({
   plugins: [
     // This plugin is enabled only in production
     enableIf(isProd, useMaskedErrors()),
+    // you can also pass function
+    enableIf(isProd, () => useMaskedErrors()),
     // ... other plugins ...
   ],
 });