Add a node default region provider

Author: jeskew

packages/region-provider-node/.gitignore

@@ -0,0 +1,15 @@
+/src/
+/coverage/
+tsconfig.test.json
+
+*.spec.js
+*.spec.d.ts
+*.spec.js.map
+
+*.mock.js
+*.mock.d.ts
+*.mock.js.map
+
+*.fixture.js
+*.fixture.d.ts
+*.fixture.js.map

packages/region-provider-node/__tests__/fromSharedConfigFiles.ts

@@ -2,11 +2,12 @@
   "name": "@aws/region-provider",
   "version": "0.0.1",
   "private": true,
-  "description": "AWS region provider core. Provides an abstraction for sourcing a region from one or more asynchronous sources",
-  "main": "index.js",
+  "description": "AWS region provider for Node.JS. Will determine the default region to use for AWS clients by checking known environment variables and shared configuration files",
+  "main": "./build/index.js",
+  "typings": "./build/index.d.ts",
   "scripts": {
     "prepublishOnly": "tsc",
-    "pretest": "tsc",
+    "pretest": "tsc -p tsconfig.test.json",
     "test": "jest"
   },
   "keywords": [
@@ -16,10 +17,13 @@
   "author": "[email protected]",
   "license": "Apache-2.0",
   "dependencies": {
+    "@aws/property-provider": "^0.0.1",
+    "@aws/shared-ini-file-loader": "^0.0.1",
     "@aws/types": "^0.0.1"
   },
   "devDependencies": {
     "@types/jest": "^20.0.2",
+    "@types/node": "^7.0.12",
     "jest": "^20.0.4",
     "typescript": "^2.3"
   }

packages/region-provider-node/index.ts

@@ -0,0 +1,99 @@
+import {defaultProvider} from './defaultProvider';
+import {ProviderError} from '@aws/property-provider';
+
+jest.mock('./fromEnv', () => {
+    const envProvider = jest.fn();
+    return {
+        fromEnv: jest.fn(() => envProvider),
+    };
+});
+import {fromEnv, EnvConfiguration} from './fromEnv';
+
+jest.mock('./fromSharedConfigFiles', () => {
+    const iniProvider = jest.fn();
+    return {
+        fromSharedConfigFiles: jest.fn(() => iniProvider),
+    };
+});
+import {fromSharedConfigFiles, SharedConfigInit} from './fromSharedConfigFiles';
+
+beforeEach(() => {
+    (fromEnv() as any).mockClear();
+    (fromSharedConfigFiles() as any).mockClear();
+    (fromEnv as any).mockClear();
+    (fromSharedConfigFiles as any).mockClear();
+});
+
+describe('defaultProvider', () => {
+    it(
+        'should stop after the environmental provider if a region has been found',
+        async () => {
+            const region = 'foo';
+            (fromEnv() as any).mockImplementation(() => Promise.resolve(region));
+
+            expect(await defaultProvider()()).toEqual(region);
+            expect((fromEnv() as any).mock.calls.length).toBe(1);
+            expect((fromSharedConfigFiles() as any).mock.calls.length).toBe(0);
+        }
+    );
+
+    it(
+        'should continue on to the ini provider if no environment variable region has been found',
+        async () => {
+            const region = 'foo';
+
+            (fromEnv() as any).mockImplementation(() => Promise.reject(new ProviderError('Nothing here!')));
+            (fromSharedConfigFiles() as any).mockImplementation(() => Promise.resolve(region));
+
+            expect(await defaultProvider()()).toEqual(region);
+            expect((fromEnv() as any).mock.calls.length).toBe(1);
+            expect((fromSharedConfigFiles() as any).mock.calls.length).toBe(1);
+        }
+    );
+
+    it('should pass configuration on to the env provider', async () => {
+        const envConfig: EnvConfiguration = {
+            environmentVariableName: 'foo',
+        };
+
+        (fromEnv() as any).mockImplementation(() => Promise.resolve('region'));
+        (fromEnv as any).mockClear();
+
+        await expect(defaultProvider(envConfig)()).resolves;
+
+        expect((fromEnv as any).mock.calls.length).toBe(1);
+        expect((fromEnv as any).mock.calls[0][0]).toBe(envConfig);
+    });
+
+    it('should pass configuration on to the ini provider', async () => {
+        const iniConfig: SharedConfigInit = {
+            profile: 'foo',
+            filepath: '/home/user/.secrets/credentials.ini',
+            configFilepath: '/home/user/.secrets/credentials.ini',
+        };
+
+        (fromEnv() as any).mockImplementation(() => Promise.reject(new ProviderError('Keep moving!')));
+        (fromSharedConfigFiles() as any).mockImplementation(() => Promise.resolve('region'));
+
+        (fromSharedConfigFiles as any).mockClear();
+
+        await expect(defaultProvider(iniConfig)()).resolves;
+
+        expect((fromSharedConfigFiles as any).mock.calls.length).toBe(1);
+        expect((fromSharedConfigFiles as any).mock.calls[0][0]).toBe(iniConfig);
+    });
+
+    it('should return the same promise across invocations', async () => {
+        const region = 'foo';
+        (fromEnv() as any).mockImplementation(() => Promise.resolve(region));
+
+        const provider = defaultProvider();
+
+        expect(await provider()).toEqual(region);
+
+        expect(provider()).toBe(provider());
+
+        expect(await provider()).toEqual(region);
+        expect((fromEnv() as any).mock.calls.length).toBe(1);
+    });
+});

packages/region-provider-node/lib/fromEnv.ts

@@ -0,0 +1,17 @@
+import {EnvConfiguration, fromEnv} from './fromEnv';
+import {SharedConfigInit, fromSharedConfigFiles} from './fromSharedConfigFiles';
+import {chain, memoize} from '@aws/property-provider';
+import {Provider} from '@aws/types';
+
+export type RegionProviderConfiguration =
+    EnvConfiguration &
+    SharedConfigInit;
+
+export function defaultProvider(
+    configuration: RegionProviderConfiguration = {}
+): Provider<string> {
+    return memoize(chain(
+        fromEnv(configuration),
+        fromSharedConfigFiles(configuration)
+    ));
+}

packages/region-provider-node/package.json

@@ -1,4 +1,5 @@
-import {fromEnv, ENV_REGION} from '../lib/fromEnv';
+import {fromEnv, ENV_REGION} from './fromEnv';
+import {ProviderError} from '@aws/property-provider';
 
 describe('fromEnv', () => {
     const ENV_CUSTOM = 'AWS_DEFAULT_REGION';
@@ -21,12 +22,18 @@ describe('fromEnv', () => {
     });
 
     it(`should reject the promise is ${ENV_REGION} is not set`, async () => {
-        await expect(fromEnv()()).rejects;
+        await expect(fromEnv()())
+            .rejects
+            .toMatchObject(new ProviderError(
+                `No value defined for the AWS_REGION environment variable`
+            ));
     });
 
     it('should allow specifying custom environment variables', async () => {
         process.env[ENV_CUSTOM] = 'eu-central-35';
         expect(process.env[ENV_REGION]).toBeUndefined();
-        expect(await fromEnv(ENV_CUSTOM)()).toBe(process.env[ENV_CUSTOM]);
+        expect(
+            await fromEnv({environmentVariableName: ENV_CUSTOM})()
+        ).toBe(process.env[ENV_CUSTOM]);
     });
 });