feat: Add lifecycle hooks for nitric.

src/environment/environment.ts

@@ -0,0 +1,75 @@
+// Copyright 2021, Nitric Technologies Pty Ltd.
+//
+// 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.
+
+// The environment variable key that will be used to determine the current Nitric lifecycle/executing environment
+const NITRIC_ENVIRONMENT = "NITRIC_ENVIRONMENT";
+
+// Possible nitric execution environments
+enum EnvironmentStage {
+    // Local development run (using nitric run/start)
+    LocalRun = "run",
+    // Local development requirements building/collection (using nitric up) 
+    Build = "build",
+    // When the code is running in a deployed environment
+    Cloud = "cloud",
+}
+
+const getCurrentEnvironment = (): EnvironmentStage => {
+    const lifecycle = process.env[NITRIC_ENVIRONMENT];
+    if (!lifecycle || !Object.values(EnvironmentStage).includes(lifecycle as EnvironmentStage)) {
+        throw new Error(`Unable to determine the current Nitric lifecycle, please ensure the ${NITRIC_ENVIRONMENT} environment variable is set`);
+    }
+    return lifecycle as EnvironmentStage;
+}
+
+// Check if the current environment is one of the provided stages
+const isInEnvironment = (stage: EnvironmentStage[]) => {
+    const currentStage = getCurrentEnvironment();
+    return stage.includes(currentStage);
+}
+
+// If the current environment is one of the provided stages, execute the provided callback
+const whenInEnvironments = <T>(stage: EnvironmentStage[], callback: EnvCallback<T>): T | undefined => {
+    if (isInEnvironment(stage)) {
+        return callback();
+    }
+}
+
+const whenLocalRun = <T>(callback: EnvCallback<T>) => whenInEnvironments([EnvironmentStage.LocalRun], callback);
+
+
+const whenBuild = <T>(callback: EnvCallback<T>) => whenInEnvironments([EnvironmentStage.Build], callback);
+
+const whenCloud = <T>(callback: EnvCallback<T>) => whenInEnvironments([EnvironmentStage.Cloud], callback);
+
+type EnvCallback<T> = () => T;
+
+export const Environment = {
+    // Check if the current environment is one of the provided stages
+    is: isInEnvironment,
+    // Check if the current environment is a local run
+    isLocalRun: () => isInEnvironment([EnvironmentStage.LocalRun]),
+    // Check if the current environment is a build
+    isBuild: () => isInEnvironment([EnvironmentStage.Build]),
+    // Check if the current environment is a cloud environment
+    isCloud: () => isInEnvironment([EnvironmentStage.Cloud]),
+    // If the current environment is one of the provided stages, execute the provided callback
+    when: whenInEnvironments,
+    // If the current environment is a local run, execute the provided callback
+    whenLocalRun,
+    // If the current environment is a build, execute the provided callback
+    whenBuild,
+    // If the current environment is a cloud environment, execute the provided callback
+    whenCloud,
+}

src/environment/index.ts

@@ -0,0 +1,15 @@
+// Copyright 2021, Nitric Technologies Pty Ltd.
+//
+// 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.
+
+export * from "./environment";

src/index.ts

@@ -16,3 +16,4 @@ export * from './resources';
 export * from './types';
 export * from './context';
 export * from './handlers';
+export * from './environment';