Reduce PowerShell Lambda INIT time by omitting unwanted files from pa…

[sankettangade]

Description of changes:

New-AWSPowerShellLambdaPackage now strips files that have no purpose at Lambda runtime from AWS-authored PowerShell modules during packaging:

• Files stripped: *.xml (PowerShell help XML, .NET XMLDoc, PowerShellGet metadata) and *.pdb (debug symbols).
• Scope: Only AWSPowerShell.NetCore and AWS.Tools.* modules under the package's Modules/ directory. Third-party PowerShell modules are not touched.

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Measured Impact

Cold-start INIT measured against a matched-runtime baseline (dotnet10, Microsoft.PowerShell.SDK 7.5.4, 512 MB, us-east-1, 100 cold starts each).

AWS.Tools.EC2 example (largest module tested):

Architecture	Mean Init (Unstripped)	Mean Init (Stripped)	Δ ms	Improvement %
x86_64	2563.7 ms	2448.6 ms	−115.1 ms	4.49%
arm64	2939.6 ms	2805.6 ms	−134.0 ms	4.56%

EC2 also showed a notable tail-latency improvement: P99 dropped from 4697.8 ms → 2954.4 ms on x86_64 (−1.7s).

Across services, the improvement scales with bytes stripped per module, averaging ~5% INIT reduction on chunky modules. All users of New-AWSPowerShellLambdaPackage benefit automatically with no script or invocation changes.

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Test Plan

• All Pester tests pass (Invoke-Pester PowerShell/Tests/)
• Manual end-to-end packaging of STS, S3, EC2 handlers on x86_64 and arm64
• Functions deployed to AWS Lambda and invoked successfully without Module load failed or Cannot find errors in CloudWatch logs
• Cold-start benchmarks (100 invocations × 6 functions) compared against matched-runtime unstripped baseline

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[Copilot]

Pull request overview

This PR reduces AWS Lambda PowerShell package size and cold-start INIT time by stripping runtime-unneeded files from AWS-authored PowerShell modules during dependency preparation.

Changes:

• Adds constants and helper logic to remove XML help/docs and PDB files from AWSPowerShell.NetCore and AWS.Tools.* modules.
• Invokes the strip step after dependent module preparation.
• Adds Pester coverage for stripping behavior and updates module version/changelog.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
PowerShell/Module/Private/_Constants.ps1	Defines strip file filters and AWS-authored module name patterns.
PowerShell/Module/Private/_DeploymentFunctions.ps1	Adds _stripAwsModuleFiles and calls it during dependency preparation.
PowerShell/Tests/_stripAwsModuleFiles.Tests.ps1	Adds tests for stripping, preservation, third-party modules, and no-op cases.
PowerShell/Tests/Get-AWSPowerShelLambdaTemplate.Tests.ps1	Moves helper and mocks into BeforeAll.
PowerShell/Module/AWSLambdaPSCore.psd1	Bumps PowerShell module version to 5.0.2.0.
CHANGELOG.md	Adds release notes for the packaging optimization.

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[philasmar]

You should not modify the CHANGELOG.md manually. Add a change file to your PR. Follow this guide to do so https://github.com/aws/aws-lambda-dotnet/blob/master/CONTRIBUTING.md#adding-a-change-file-to-your-contribution-branch.

[GarrettBeatty]

@philasmar this powershell module file and related things is not configured for autover i dont think

[sankettangade]

You should not modify the CHANGELOG.md manually. Add a change file to your PR. Follow this guide to do so https://github.com/aws/aws-lambda-dotnet/blob/master/CONTRIBUTING.md#adding-a-change-file-to-your-contribution-branch.

@philasmar As Garrett said, PowerShell files are not configured for auto changelog generation, I checked the previous PRs that modify these same files and saw we had to add the changelog manually.