fix: not requiring @aws-sdk/client-s3 installed if not using lib-storage mock

.gitignore

@@ -4,3 +4,4 @@ node_modules/
 dist/
 coverage/
 compatibility/
+verdaccio-storage/

README.md

@@ -272,6 +272,7 @@ await s3Upload.done();
 
 You can call `mockLibStorageUpload()` without providing an S3Client mock.
 In that case, the client mock will be created and returned from the function.
+However, you still need to have `@aws-sdk/client-s3` installed as a dependency.
 
 #### Paginated operations
 

package.json

@@ -32,7 +32,9 @@
     "size": "size-limit",
     "size:analyze": "size-limit --why",
     "release": "standard-version",
-    "generate-compatibility": "ts-node ./misc/generate-compatibility.ts"
+    "generate-compatibility": "ts-node ./misc/generate-compatibility.ts",
+    "verdaccio": "rimraf verdaccio-storage && verdaccio -c verdaccio.yml",
+    "local-publish": "npm publish --registry http://localhost:4873/"
   },
   "main": "dist/cjs/index.js",
   "types": "dist/types/index.d.ts",
@@ -77,7 +79,8 @@
     "ts-node": "10.2.1",
     "tsd": "0.17.0",
     "typedoc": "0.22.3",
-    "typescript": "4.2.4"
+    "typescript": "4.2.4",
+    "verdaccio": "5.1.5"
   },
   "jest": {
     "preset": "ts-jest",

src/libStorage.ts

@@ -1,5 +1,5 @@
 import {AwsClientStub} from './awsClientStub';
-import {CreateMultipartUploadCommand, S3Client, UploadPartCommand} from '@aws-sdk/client-s3';
+import type {S3Client as S3ClientType} from '@aws-sdk/client-s3';
 import {mockClient} from './mockClient';
 
 /**
@@ -9,7 +9,20 @@ import {mockClient} from './mockClient';
  * If S3Client mocks is not provided, a new one is created.
  * @param s3Mock S3Client mock created with {@link mockClient} function
  */
-export const mockLibStorageUpload = (s3Mock?: AwsClientStub<S3Client>): AwsClientStub<S3Client> => {
+export const mockLibStorageUpload = (s3Mock?: AwsClientStub<S3ClientType>): AwsClientStub<S3ClientType> => {
+    /*
+     * Not all library consumers also use @aws-sdk/client-s3. Importing it in a standard TS way
+     * would cause errors for them, as the module would be tried to found and import.
+     * Instead, we require classes from it dynamically in the scope of the function.
+     *
+     * Another solution would be to not export this function in the index.ts
+     * and instead have consumers to import it from 'aws-sdk-client-mock/libStorage'.
+     * This however turned out to be complicated to achieve in terms of exposing modules properly
+     * for CommonJS and ES modules.
+     */
+    // eslint-disable-next-line @typescript-eslint/no-var-requires,@typescript-eslint/no-unsafe-assignment
+    const {CreateMultipartUploadCommand, S3Client, UploadPartCommand} = require('@aws-sdk/client-s3');
+
     if (!s3Mock) {
         s3Mock = mockClient(S3Client);
     }

verdaccio.yml

@@ -0,0 +1,6 @@
+storage: verdaccio-storage
+
+packages:
+  "**":
+    access: $all
+    publish: $all