Increased esbuild bundle size on latest versions (v3.930.0+) due to tree-shaking & expression in object initializer key

[vovkiv94]

Checkboxes for prior research

• I've gone through Developer Guide and API reference
• I've checked AWS Forums and StackOverflow.
• I've searched for previous similar issues and didn't find any solution.

Describe the bug

While upgrading aws-sdk v3 clients from 3.806.0 to 3.957.0 in my project, I notices significant increase in bundle size. For example, in our case client-ec2 grew from 30kbs to 492kbs (all we use is EC2Client and 3 commands)

Regression Issue

• Select this option if this issue appears to be a regression.

SDK version number

@aws-sdk/client-ec2@3.957.0,@aws-sdk/client-@3.957.0

Which JavaScript Runtime is this issue in?

Node.js

Details of the browser/Node.js/ReactNative version

v20.19.6

Reproduction Steps

package.json
index.js

1. Create a folder with these 2 files
2. npm install & npm test
3. Note client-ec2 size in the bundle (should be 25kbs)
4. In package.json update: "@aws-sdk/client-ec2": "3.806.0" =>"@aws-sdk/client-ec2": "3.957.0"
5. npm install & npm test
6. Note client-ec2 size increase in the bundle (should be 485kbs)

Observed Behavior

Bundle sized significantly increased

Expected Behavior

Bundle sized should remain the same

Possible Solution

No response

Additional Information/Context

No response

[trivikr]

The provided setup shows that bundle size increased from 46.7 kB in @aws-sdk/client-ec2@3.806.0 to 127.17 in @aws-sdk/client-ec2@3.957.0

Minimal repro for reproduction https://github.com/trivikr/test-aws-sdk-js-size-limit/tree/433241472762ead658315df4033efc2c9a5b8d51

[trivikr]

From further testing, it appears that bundle size increase was introduced in v3.930.0

Minimal repro for reproduction: https://github.com/trivikr/test-aws-sdk-js-size-limit/tree/935b3d18423cc1cf867aed69d57e2a91afbc5909

While we dive deep on what the issue is, if you're impacted by this bundle size increase please use @aws-sdk/client-ec2 to v3.929.0

[trivikr]

Comparing the esbuild visualizer side by side, it seems that esbuild is not tree shaking schemas/schemas_0.js

Screenshot

[trivikr]

For v3.930.0 release, our tests showed bundle size decrease for esbuild sdk-ec2-aggregate.ts from 1.105 mb to 829 kb.
But it's for aggregate client and not barebones client provided in the minimal repro of this issue.

2a1737e#diff-da306e94812133d21ec69066e9dc4999fd5f11231c9e366e9e60a2f780c29389

[trivikr]

These is the config that we use for esbuild benchmarking
https://github.com/aws/aws-sdk-js-v3/blob/main/tests/bundlers/runner/BundlerSizeBenchmarker.mjs#L100-L109

The documentation of size-limit is not very clear, but I tried to set up modifyEsbuildConfig to specify browser and esm.
But it doesn't seem to be picking it up.
https://github.com/trivikr/test-aws-sdk-js-size-limit/tree/modifyEsbuildConfig

I think it's best to build bundle directly using esbuild, instead of using size-limit.

[trivikr]

Assuming this test is for browser, I followed Bundling for the browser with main-fields

Minimal script run: esbuild index.js --bundle --minify --main-fields=browser,module,main --outfile=out.js

@aws-sdk/client-ec2@3.929.0

  out.js  109.0kb

@aws-sdk/client-ec2@3.930.0

  out.js  570.5kb

Minimal repro in https://github.com/trivikr/test-aws-sdk-js-size-limit/tree/esbuild

This issue seems to be impacting barebones clients who are using schemas, and the difference is highest in large clients (like EC2)