chore(middleware-endpoint): add getEndpointUrlConfig

packages/middleware-endpoint/package.json

@@ -24,6 +24,7 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@smithy/middleware-serde": "workspace:^",
+    "@smithy/node-config-provider": "workspace:^",
     "@smithy/types": "workspace:^",
     "@smithy/url-parser": "workspace:^",
     "@smithy/util-middleware": "workspace:^",

packages/middleware-endpoint/src/adaptors/getEndpointUrlConfig.spec.ts

@@ -0,0 +1,63 @@
+import { getEndpointUrlConfig } from "./getEndpointUrlConfig";
+
+const ENV_ENDPOINT_URL = "AWS_ENDPOINT_URL";
+const CONFIG_ENDPOINT_URL = "endpoint_url";
+
+describe(getEndpointUrlConfig.name, () => {
+  const serviceId = "foo";
+  const endpointUrlConfig = getEndpointUrlConfig(serviceId);
+
+  const mockEndpoint = "https://mock-endpoint.com";
+  const ORIGINAL_ENV = process.env;
+
+  beforeEach(() => {
+    process.env = {};
+  });
+
+  afterEach(() => {
+    process.env = ORIGINAL_ENV;
+  });
+
+  describe("environmentVariableSelector", () => {
+    const serviceMockEndpoint = `${mockEndpoint}/${serviceId}`;
+
+    beforeEach(() => {
+      process.env[ENV_ENDPOINT_URL] = mockEndpoint;
+      process.env[`${ENV_ENDPOINT_URL}_${serviceId.toUpperCase()}`] = serviceMockEndpoint;
+    });
+
+    it("returns service specific endpoint from environment variable, if available", () => {
+      expect(endpointUrlConfig.environmentVariableSelector(process.env)).toEqual(serviceMockEndpoint);
+    });
+
+    it("returns endpoint from environment variable, if available", () => {
+      process.env[`${ENV_ENDPOINT_URL}_${serviceId.toUpperCase()}`] = undefined;
+      expect(endpointUrlConfig.environmentVariableSelector(process.env)).toEqual(mockEndpoint);
+    });
+
+    it("returns undefined, if endpoint not available in environment variables", () => {
+      process.env[ENV_ENDPOINT_URL] = undefined;
+      process.env[`${ENV_ENDPOINT_URL}_${serviceId.toUpperCase()}`] = undefined;
+      expect(endpointUrlConfig.environmentVariableSelector(process.env)).toBeUndefined();
+    });
+  });
+
+  describe("configFileSelector", () => {
+    it("returns service specific endpoint from config file, if available", () => {
+      // ToDo
+    });
+
+    it("returns endpoint from config file, if available", () => {
+      const profile = { [CONFIG_ENDPOINT_URL]: mockEndpoint };
+      expect(endpointUrlConfig.configFileSelector(profile)).toEqual(mockEndpoint);
+    });
+
+    it("returns undefined, if endpoint not available in config", () => {
+      expect(endpointUrlConfig.environmentVariableSelector({})).toBeUndefined();
+    });
+  });
+
+  it("returns undefined by default", () => {
+    expect(endpointUrlConfig.default).toBeUndefined();
+  });
+});

packages/middleware-endpoint/src/adaptors/getEndpointUrlConfig.ts

@@ -0,0 +1,35 @@
+import { LoadedConfigSelectors } from "@smithy/node-config-provider";
+
+const ENV_ENDPOINT_URL = "AWS_ENDPOINT_URL";
+const CONFIG_ENDPOINT_URL = "endpoint_url";
+
+export const getEndpointUrlConfig = (serviceId: string): LoadedConfigSelectors<string | undefined> => ({
+  environmentVariableSelector: (env) => {
+    // The value provided by a service-specific environment variable.
+    const serviceEndpointUrlSections = [ENV_ENDPOINT_URL, serviceId.toUpperCase()];
+    const serviceEndpointUrl = env[serviceEndpointUrlSections.join("_")];
+    if (serviceEndpointUrl) return serviceEndpointUrl;
+
+    // The value provided by the global endpoint environment variable.
+    const endpointUrl = env[ENV_ENDPOINT_URL];
+    if (endpointUrl) return endpointUrl;
+
+    return undefined;
+  },
+
+  configFileSelector: (profile) => {
+    // The value provided by a service-specific parameter from a services definition section
+    // referenced in a profile in the shared configuration file.
+
+    // ToDo: profile is selected one. It does not have access to other 'services' section.
+    // We should call loadSharedConfigFiles directly.
+
+    // The value provided by the global parameter from a profile in the shared configuration file.
+    const endpointUrl = profile[CONFIG_ENDPOINT_URL];
+    if (endpointUrl) return endpointUrl;
+
+    return undefined;
+  },
+
+  default: undefined,
+});

yarn.lock

@@ -2071,6 +2071,7 @@ __metadata:
   resolution: "@smithy/middleware-endpoint@workspace:packages/middleware-endpoint"
   dependencies:
     "@smithy/middleware-serde": "workspace:^"
+    "@smithy/node-config-provider": "workspace:^"
     "@smithy/types": "workspace:^"
     "@smithy/url-parser": "workspace:^"
     "@smithy/util-middleware": "workspace:^"