[BUG]: HelmInstaller@1 treats alpha versions as stable

[NoDataAvailable]

New issue checklist

• I searched for existing GitHub issues
• I read pipeline troubleshooting guide
• I checked how to collect logs

Task name

HelmInstaller

Task version

1.246.3

Issue Description

As-of the release of helm 4.0.0-alpha.1, the filtering logic for the "latest stable" release of helm is broken. The current logic in getStableHelmVersion() only checks for the 'rc' string as an indicator of a non-stable version; with the release of 4.0.0-alpha.1, it should also check for 'alpha'.

Environment type (Please select at least one enviroment where you face this issue)

• Self-Hosted
• Microsoft Hosted
• VMSS Pool
• Container

Azure DevOps Server type

dev.azure.com (formerly visualstudio.com)

Azure DevOps Server Version (if applicable)

No response

Operation system

Azure Linux 3.0

Relevant log output

Starting: 📥 Install Helm
==============================================================================
Task         : Helm tool installer
Description  : Install Helm on an agent machine
Version      : 1.246.3
Author       : Microsoft Corporation
Help         : https://aka.ms/azpipes-helm-installer-tsg
==============================================================================
Downloading: https://api.github.com/repos/helm/helm/releases
Downloading: https://get.helm.sh/helm-v4.0.0-alpha.1-linux-amd64.zip
Extracting archive
/bin/unzip /mnt/vss/_work/_temp/helm-v4.0.0-alpha.1-b2d46852-9a1d-445b-8690-bb9a29b67370.zip
Archive:  /mnt/vss/_work/_temp/helm-v4.0.0-alpha.1-b2d46852-9a1d-445b-8690-bb9a29b67370.zip
   creating: linux-amd64/
  inflating: linux-amd64/README.md   
  inflating: linux-amd64/LICENSE     
  inflating: linux-amd64/helm        

Caching tool: helm 4.0.0-alpha.1 x64
Prepending PATH environment variable with directory: /opt/hostedtoolcache/helm/4.0.0-alpha.1/x64/linux-amd64
Verifying helm installation...
Finishing: 📥 Install Helm

Full task logs with system.debug enabled

 [REPLACE THIS WITH YOUR INFORMATION] 

Repro steps

[sigv]

Current workaround until a solution is delivered is to lock a version explicitly:

- task: HelmInstaller@1
  inputs:
    helmVersionToInstall: v3.18.6

Understandably, this is sub-optimal for many pipelines.

---

This also affects HelmInstaller@0 in same way, as they share historical codebase and implementation decisions.

[mohag]

The GitHub API also has a prerelease flag in the output, which might be an alternative to string searches in the version number.

https://docs.github.com/en/rest/releases/releases?apiVersion=2022-11-28#list-releases

[mot256]

Added a possible fix microsoft/azure-pipelines-tasks-common-packages#491

[plieberg]

This bug is also valid for beta releases as 4.0.0-beta.1 for Helm is being picked up as latest when it should not be counted as stable.