s3 interface initialization inside or outside the function

[s1mrankaur]

Confirm by changing [ ] to [x] below:

• [ x] I've gone through Developer Guide and API reference
• [x ] I've checked AWS Forums and StackOverflow for answers

We currently have

export function s3Call(action: string, params: any): Promise<any> {
const s3 = new AWS.S3();
return s3[action](params).promise();
}

I tried to change it to

    const s3 = new AWS.S3();
    export function s3Call(action: string, params: any): Promise<any> {
    return s3[action](params).promise();
    }

but on running the unit test, ran into the following error

> failed to get the current sub/segment from the context new s3

The unit test itself is pretty simple:

    describe("uploadImage tests", () => {
    it("should return correct image url", async () => { process.env.IMAGE_UPLOAD_BUCKET_NAME = 'TestBucket'; process.env.AWS_REGION = 'us-west-2';
    const putObject = jest.fn().mockImplementation(() => Promise.resolve({})); 
    AWSMock.mock('S3', 'putObject', putObject);
    const bucketUrl = https://${process.env.IMAGE_UPLOAD_BUCKET_NAME}.s3-${process.env.AWS_REGION}.amazonaws.com/; 
    const result = await uploadImage(imageData, bucketUrl); expect(result).toContain(process.env.IMAGE_UPLOAD_BUCKET_NAME); 
expect(result).toContain(process.env.AWS_REGION); 
AWSMock.restore('S3');   }); });

How can the s3 interface be initialized once? and why do we see this error once when s3 initialization is taken out of the function?

[vudh1]

Hi @s1mrankaur thanks for reaching out. S3 interface needs to be initialized inside the function in this case because the test function needs to use the instance created.