Azure Pipeline Copy Secure file into build folder - azure-devops

Question

I've a vite/svelte project which uses .env files for environment settings. I also have an Azure Pipeline which contains a secure file .env.staging this is on the .gitignore list of the associated repo. I'd like to download this secure file, copy it to my build directory and then have it's contents read when I run vite build --mode staging (well, npm run build:staging which includes vite build...)
When run locally from my machine npm run build:staging works as expected and reads the .env.staging file, however it seems to get ignored when used in the pipeline, am I doing anything wrong?
Here's my yml.
trigger:
- main
pool:
vmImage: 'ubuntu-latest'
steps:
- task: DownloadSecureFile#1
name: "dotenvStaging"
inputs:
secureFile: '.env.staging'
displayName: "Download .env.staging"
- task: NodeTool#0
inputs:
versionSpec: 14.15.4
displayName: "Install Node.JS"
- task: CopyFiles#2
inputs:
contents: "$(Agent.TempDirectory)/.env.staging"
targetFolder: "$(Agent.BuildDirectory)"
displayName: "Import .env.staging"
- script: npm install
displayName: "npm install"
- script: npm run build:staging
displayName: "npm run build:staging"
- task: ArchiveFiles#2
inputs:
rootFolderOrFile: 'dist'
archiveType: 'zip'
archiveFile: '$(Build.ArtifactStagingDirectory)/$(Build.BuildId).zip'
#replaceExistingArchive: true
#verbose: # Optional
#quiet: # Optional
displayName: "Create archive"
- task: PublishBuildArtifacts#1
inputs:
PathtoPublish: '$(Build.ArtifactStagingDirectory)/$(Build.BuildId).zip'
ArtifactName: 'drop'
publishLocation: 'Container'
displayName: "Publish archive"
I'm not sure if CopyFiles#2 is doing what I expect or not as it just matches the content parameter to copy whatever files match, which could be 0 if I'm writing it wrong...
Another note, I also tried using $(dotenvStaging.secureFilePath) as the content parameter, but it doesn't seem to do anything either.

Answer 1

Naturally I figured it out as soon as I posted, I needed to update the CopyFiles part to specify sourceFolder, clearly it didn't like my absolute file path for content.
- task: CopyFiles#2
inputs:
sourceFolder: "$(Agent.TempDirectory)"
contents: ".env.staging"
targetFolder: "$(Agent.BuildDirectory)"
displayName: "Import .env.staging"