backend-app-api: split out ObservableConfigProxy

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
2023-01-10 16:44:50 +01:00
parent fdc1d3d8ef
commit 6420b7dc51
2 changed files with 130 additions and 112 deletions
@@ -0,0 +1,130 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * 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.
+ */
+
+import { ConfigService, LoggerService } from '@backstage/backend-plugin-api';
+import { ConfigReader } from '@backstage/config';
+import { JsonValue } from '@backstage/types';
+
+export class ObservableConfigProxy implements ConfigService {
+  private config: ConfigService = new ConfigReader({});
+
+  private readonly subscribers: (() => void)[] = [];
+
+  constructor(
+    private readonly logger: LoggerService,
+    private readonly parent?: ObservableConfigProxy,
+    private parentKey?: string,
+  ) {
+    if (parent && !parentKey) {
+      throw new Error('parentKey is required if parent is set');
+    }
+  }
+
+  setConfig(config: ConfigService) {
+    if (this.parent) {
+      throw new Error('immutable');
+    }
+    this.config = config;
+    for (const subscriber of this.subscribers) {
+      try {
+        subscriber();
+      } catch (error) {
+        this.logger.error(`Config subscriber threw error, ${error}`);
+      }
+    }
+  }
+
+  subscribe(onChange: () => void): { unsubscribe: () => void } {
+    if (this.parent) {
+      return this.parent.subscribe(onChange);
+    }
+
+    this.subscribers.push(onChange);
+    return {
+      unsubscribe: () => {
+        const index = this.subscribers.indexOf(onChange);
+        if (index >= 0) {
+          this.subscribers.splice(index, 1);
+        }
+      },
+    };
+  }
+
+  private select(required: true): ConfigService;
+  private select(required: false): ConfigService | undefined;
+  private select(required: boolean): ConfigService | undefined {
+    if (this.parent && this.parentKey) {
+      if (required) {
+        return this.parent.select(true).getConfig(this.parentKey);
+      }
+      return this.parent.select(false)?.getOptionalConfig(this.parentKey);
+    }
+
+    return this.config;
+  }
+
+  has(key: string): boolean {
+    return this.select(false)?.has(key) ?? false;
+  }
+  keys(): string[] {
+    return this.select(false)?.keys() ?? [];
+  }
+  get<T = JsonValue>(key?: string): T {
+    return this.select(true).get(key);
+  }
+  getOptional<T = JsonValue>(key?: string): T | undefined {
+    return this.select(false)?.getOptional(key);
+  }
+  getConfig(key: string): ConfigService {
+    return new ObservableConfigProxy(this.logger, this, key);
+  }
+  getOptionalConfig(key: string): ConfigService | undefined {
+    if (this.select(false)?.has(key)) {
+      return new ObservableConfigProxy(this.logger, this, key);
+    }
+    return undefined;
+  }
+  getConfigArray(key: string): ConfigService[] {
+    return this.select(true).getConfigArray(key);
+  }
+  getOptionalConfigArray(key: string): ConfigService[] | undefined {
+    return this.select(false)?.getOptionalConfigArray(key);
+  }
+  getNumber(key: string): number {
+    return this.select(true).getNumber(key);
+  }
+  getOptionalNumber(key: string): number | undefined {
+    return this.select(false)?.getOptionalNumber(key);
+  }
+  getBoolean(key: string): boolean {
+    return this.select(true).getBoolean(key);
+  }
+  getOptionalBoolean(key: string): boolean | undefined {
+    return this.select(false)?.getOptionalBoolean(key);
+  }
+  getString(key: string): string {
+    return this.select(true).getString(key);
+  }
+  getOptionalString(key: string): string | undefined {
+    return this.select(false)?.getOptionalString(key);
+  }
+  getStringArray(key: string): string[] {
+    return this.select(true).getStringArray(key);
+  }
+  getOptionalStringArray(key: string): string[] | undefined {
+    return this.select(false)?.getOptionalStringArray(key);
+  }
+}
@@ -26,7 +26,6 @@ import {
  LoadConfigOptionsRemote,
 } from '@backstage/config-loader';
 import { AppConfig, Config, ConfigReader } from '@backstage/config';
-import { JsonValue } from '@backstage/types';
 import { getPackages } from '@manypkg/get-packages';

 import { isValidUrl } from './urls';
@@ -61,117 +60,6 @@ const updateRedactionList = (
  setRootLoggerRedactionList(Array.from(values));
 };

-export class ObservableConfigProxy implements Config {
-  private config: Config = new ConfigReader({});
-
-  private readonly subscribers: (() => void)[] = [];
-
-  constructor(
-    private readonly logger: LoggerService,
-    private readonly parent?: ObservableConfigProxy,
-    private parentKey?: string,
-  ) {
-    if (parent && !parentKey) {
-      throw new Error('parentKey is required if parent is set');
-    }
-  }
-
-  setConfig(config: Config) {
-    if (this.parent) {
-      throw new Error('immutable');
-    }
-    this.config = config;
-    for (const subscriber of this.subscribers) {
-      try {
-        subscriber();
-      } catch (error) {
-        this.logger.error(`Config subscriber threw error, ${error}`);
-      }
-    }
-  }
-
-  subscribe(onChange: () => void): { unsubscribe: () => void } {
-    if (this.parent) {
-      return this.parent.subscribe(onChange);
-    }
-
-    this.subscribers.push(onChange);
-    return {
-      unsubscribe: () => {
-        const index = this.subscribers.indexOf(onChange);
-        if (index >= 0) {
-          this.subscribers.splice(index, 1);
-        }
-      },
-    };
-  }
-
-  private select(required: true): Config;
-  private select(required: false): Config | undefined;
-  private select(required: boolean): Config | undefined {
-    if (this.parent && this.parentKey) {
-      if (required) {
-        return this.parent.select(true).getConfig(this.parentKey);
-      }
-      return this.parent.select(false)?.getOptionalConfig(this.parentKey);
-    }
-
-    return this.config;
-  }
-
-  has(key: string): boolean {
-    return this.select(false)?.has(key) ?? false;
-  }
-  keys(): string[] {
-    return this.select(false)?.keys() ?? [];
-  }
-  get<T = JsonValue>(key?: string): T {
-    return this.select(true).get(key);
-  }
-  getOptional<T = JsonValue>(key?: string): T | undefined {
-    return this.select(false)?.getOptional(key);
-  }
-  getConfig(key: string): Config {
-    return new ObservableConfigProxy(this.logger, this, key);
-  }
-  getOptionalConfig(key: string): Config | undefined {
-    if (this.select(false)?.has(key)) {
-      return new ObservableConfigProxy(this.logger, this, key);
-    }
-    return undefined;
-  }
-  getConfigArray(key: string): Config[] {
-    return this.select(true).getConfigArray(key);
-  }
-  getOptionalConfigArray(key: string): Config[] | undefined {
-    return this.select(false)?.getOptionalConfigArray(key);
-  }
-  getNumber(key: string): number {
-    return this.select(true).getNumber(key);
-  }
-  getOptionalNumber(key: string): number | undefined {
-    return this.select(false)?.getOptionalNumber(key);
-  }
-  getBoolean(key: string): boolean {
-    return this.select(true).getBoolean(key);
-  }
-  getOptionalBoolean(key: string): boolean | undefined {
-    return this.select(false)?.getOptionalBoolean(key);
-  }
-  getString(key: string): string {
-    return this.select(true).getString(key);
-  }
-  getOptionalString(key: string): string | undefined {
-    return this.select(false)?.getOptionalString(key);
-  }
-  getStringArray(key: string): string[] {
-    return this.select(true).getStringArray(key);
-  }
-  getOptionalStringArray(key: string): string[] | undefined {
-    return this.select(false)?.getOptionalStringArray(key);
-  }
-}
-
 // A global used to ensure that only a single file watcher is active at a time.
 let currentCancelFunc: () => void;