From 4969c6046b21682d7e52184c60f65e1c6faf5804 Mon Sep 17 00:00:00 2001
From: Bilawal Hameed <bil@spotify.com>
Date: Thu, 26 Mar 2020 16:34:12 +0100
Subject: [PATCH] [core/apis] moved away from ts decorators

---
 packages/core/src/api/app/FeatureFlags.tsx | 24 ++++++------
 packages/core/src/testUtils/decorators.ts  | 45 ----------------------
 packages/core/tsconfig.json                |  3 +-
 3 files changed, 12 insertions(+), 60 deletions(-)
 delete mode 100644 packages/core/src/testUtils/decorators.ts

diff --git a/packages/core/src/api/app/FeatureFlags.tsx b/packages/core/src/api/app/FeatureFlags.tsx
index 55558bfc1a..6459b38f0d 100644
--- a/packages/core/src/api/app/FeatureFlags.tsx
+++ b/packages/core/src/api/app/FeatureFlags.tsx
@@ -17,15 +17,13 @@
 import React, { ComponentType, createContext, FC } from 'react';
 import { FeatureFlagName } from '../plugin/types';
 import { FeatureFlagsApi } from '../apis/definitions/featureFlags';
-import { staticImplements } from '../../testUtils';
 
 // TODO: figure out where to put implementations of APIs, both inside apps
 // but also in core/separate package.
-@staticImplements<FeatureFlagsApi>()
-export class FeatureFlags {
-  private static readonly localStorageKey = 'featureFlags';
+class FeatureFlagsImpl implements FeatureFlagsApi {
+  private readonly localStorageKey = 'featureFlags';
 
-  private static getUserEnabledFeatureFlags(): Set<FeatureFlagName> {
+  private getUserEnabledFeatureFlags(): Set<FeatureFlagName> {
     if (!('localStorage' in window)) {
       throw new Error(
         'Feature Flags are not supported on browsers without the Local Storage API',
@@ -42,9 +40,7 @@ export class FeatureFlags {
     }
   }
 
-  private static saveUserEnabledFeatureFlags(
-    flags: Set<FeatureFlagName>,
-  ): void {
+  private saveUserEnabledFeatureFlags(flags: Set<FeatureFlagName>): void {
     if (!('localStorage' in window)) {
       throw new Error(
         'Feature Flags are not supported on browsers without the Local Storage API',
@@ -59,32 +55,34 @@ export class FeatureFlags {
     );
   }
 
-  static getItem(name: FeatureFlagName): boolean {
+  getItem(name: FeatureFlagName): boolean {
     return this.getUserEnabledFeatureFlags().has(name);
   }
 
-  static enable(name: FeatureFlagName): void {
+  enable(name: FeatureFlagName): void {
     const flags = this.getUserEnabledFeatureFlags();
     flags.add(name);
     this.saveUserEnabledFeatureFlags(flags);
   }
 
-  static disable(name: FeatureFlagName): void {
+  disable(name: FeatureFlagName): void {
     const flags = this.getUserEnabledFeatureFlags();
     flags.delete(name);
     this.saveUserEnabledFeatureFlags(flags);
   }
 
-  static toggle(name: FeatureFlagName): void {
+  toggle(name: FeatureFlagName): void {
     (this.getItem(name) ? this.disable : this.enable).bind(this)(name);
   }
 }
 
+export const FeatureFlags = new FeatureFlagsImpl();
+
 /**
  * Create a shared React context for Feature Flags.
  *
  * This will be used to propagate all available feature flags to
- * Backstage components. This enables viewing all of the components.
+ * Backstage components. This enables viewing all of the available flags.
  */
 export interface FeatureFlagsEntry {
   name: FeatureFlagName;
diff --git a/packages/core/src/testUtils/decorators.ts b/packages/core/src/testUtils/decorators.ts
deleted file mode 100644
index 2cea8901b4..0000000000
--- a/packages/core/src/testUtils/decorators.ts
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Copyright 2020 Spotify AB
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/**
- * This utilizes an experimental TypeScript feature called decorators.
- * This was originally added to allow us to expose a FeatureFlags API
- * with static methods (for backwards compatibility primarily). It takes
- * an existing interface and applies the types to static methods in classes.
- *
- * @see https://www.typescriptlang.org/docs/handbook/decorators.html
- * @example
- *    interface StaticProps {
- *      append(name: string, extra: string): string;
- *      reverse(name: string): string;
- *    }
- *
- *    @staticImplements<StaticProps>()
- *    class StaticPropsClass {
- *      static append(name, extra) {
- *        return `${name}${extra}`;
- *      }
- *
- *      static reverse(name) {
- *        return name.reverse();
- *      }
- *    }
- */
-export function staticImplements<T>() {
-  return <U extends T>(constructor: U) => {
-    constructor;
-  };
-}
diff --git a/packages/core/tsconfig.json b/packages/core/tsconfig.json
index 4e024e548f..ad43a0b986 100644
--- a/packages/core/tsconfig.json
+++ b/packages/core/tsconfig.json
@@ -2,7 +2,6 @@
   "extends": "../../tsconfig.json",
   "include": ["src"],
   "compilerOptions": {
-    "noImplicitAny": false,
-    "experimentalDecorators": true
+    "noImplicitAny": false
   }
 }