chore(maintenance): avoid attaching two middlewares to ua

packages/commons/src/userAgentMiddleware.ts

@@ -33,6 +33,13 @@ const customUserAgentMiddleware = (feature: string) => {
 // @ts-ignore
 const addUserAgentMiddleware = (client, feature: string): void => {
   try {
+    if (
+      client.middlewareStack
+        .identify()
+        .includes('addPowertoolsToUserAgent: POWERTOOLS,USER_AGENT')
+    ) {
+      return;
+    }
     client.middlewareStack.addRelativeTo(
       customUserAgentMiddleware(feature),
       middlewareOptions

packages/commons/tests/unit/userAgentMiddleware.test.ts

@@ -3,12 +3,26 @@ import { InvokeCommand, LambdaClient } from '@aws-sdk/client-lambda';
 import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
 import { ScanCommand } from '@aws-sdk/lib-dynamodb';
 import { GetParameterCommand, SSMClient } from '@aws-sdk/client-ssm';
-import { version as PT_VERSION } from '../../package.json';
+import { PT_VERSION } from '../../src/version';
 import { AppConfigDataClient } from '@aws-sdk/client-appconfigdata';
 import {
   GetSecretValueCommand,
   SecretsManagerClient,
 } from '@aws-sdk/client-secrets-manager';
+import { RelativeMiddlewareOptions } from '@aws-sdk/types/dist-types/middleware';
+
+type SupportedSdkClients =
+  | LambdaClient
+  | DynamoDBClient
+  | SSMClient
+  | SecretsManagerClient
+  | AppConfigDataClient;
+
+type SupportedSdkCommands =
+  | InvokeCommand
+  | ScanCommand
+  | GetParameterCommand
+  | GetSecretValueCommand;
 
 const options = {
   region: 'us-east-1',
@@ -20,6 +34,57 @@ const options = {
   },
 };
 
+const assertMiddleware = (feature: string) => {
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore
+  return (next) => (args) => {
+    const userAgent = args?.request?.headers['user-agent'];
+    expect(userAgent).toContain(`PT/${feature}/${PT_VERSION} PTEnv/NA`);
+    // make sure it's at the end of the user agent
+    expect(
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
+      userAgent
+        ?.split(' ')
+        .slice(userAgent?.split(' ').length - 2) // take the last to entries of the user-agent header
+        .join(' ')
+    ).toEqual(`PT/${feature}/${PT_VERSION} PTEnv/NA`);
+
+    return next(args);
+  };
+};
+
+const assertMiddlewareOptions: RelativeMiddlewareOptions = {
+  relation: 'after',
+  toMiddleware: 'addPowertoolsToUserAgent',
+  name: 'testUserAgentHeader',
+  tags: ['TEST'],
+};
+
+const runCommand = async (
+  client: SupportedSdkClients,
+  command: SupportedSdkCommands
+): Promise<unknown> => {
+  try {
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    return await client.send(command);
+  } catch (e) {
+    // throw only jest errors and swallow the SDK client errors like credentials or connection issues
+    if (
+      e instanceof Error &&
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
+      e.matcherResult !== undefined &&
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
+      e.matcherResult.pass === false
+    ) {
+      throw e;
+    }
+  }
+};
+
 describe('Given a client of instance: ', () => {
   it.each([
     {
@@ -57,44 +122,15 @@ describe('Given a client of instance: ', () => {
       );
 
       client.middlewareStack.addRelativeTo(
-        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-        // @ts-ignore
-        (next) => (args) => {
-          const userAgent = args?.request?.headers['user-agent'];
-          expect(userAgent).toContain(`PT/my-feature/${PT_VERSION} PTEnv/NA`);
-          // make sure it's at the end of the user agent
-          expect(
-            // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-            // @ts-ignore
-            userAgent
-              ?.split(' ')
-              .slice(userAgent?.split(' ').length - 2) // take the last to entries of the user-agent header
-              .join(' ')
-          ).toEqual(`PT/my-feature/${PT_VERSION} PTEnv/NA`);
-
-          return next(args);
-        },
-        {
-          relation: 'after',
-          toMiddleware: 'addPowertoolsToUserAgent',
-          name: 'testUserAgentHeader',
-          tags: ['TEST'],
-        }
+        assertMiddleware('my-feature'),
+        assertMiddlewareOptions
       );
 
-      try {
-        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-        // @ts-ignore
-        await client.send(command);
-      } catch (e) {
-        if (e instanceof Error && e.name === 'JestAssertionError') {
-          throw e;
-        }
-      }
+      await runCommand(client, command);
     }
   );
 
-  it('should not throw erro, when client fails to add middleware', () => {
+  it('should not throw error, when client fails to add middleware', () => {
     // create mock client that throws error when adding middleware
     const client = {
       middlewareStack: {
@@ -106,4 +142,21 @@ describe('Given a client of instance: ', () => {
 
     expect(() => addUserAgentMiddleware(client, 'my-feature')).not.toThrow();
   });
+
+  it('should no-op if we add the middleware twice', async () => {
+    const client = new LambdaClient(options);
+    const command = new InvokeCommand({ FunctionName: 'test', Payload: '' });
+    addUserAgentMiddleware(client, 'my-feature');
+    addUserAgentMiddleware(client, 'your-feature');
+
+    client.middlewareStack.addRelativeTo(
+      assertMiddleware('my-feature'),
+      assertMiddlewareOptions
+    );
+    await runCommand(client, command);
+
+    expect(client.middlewareStack.identify()).toContain(
+      'addPowertoolsToUserAgent: POWERTOOLS,USER_AGENT'
+    );
+  });
 });