Add IgnoreStopIfOnceExists setting for write-only deployments

[Copilot]

Write-only deployments (e.g., WebDeploy without "remove files" option) leave usync.stop files from previous runs, blocking subsequent imports even when a new usync.once file is deployed.

Changes

Configuration

• Added IgnoreStopIfOnceExists boolean setting (default: false)
• When enabled, usync.once overrides usync.stop blocking behavior

Implementation

• Extracted import decision logic into ShouldProceedWithImport() method
• Added HasOnceFile() helper to check once file existence
• Import now proceeds when: no stop file exists, OR (stop file + setting enabled + once file exists)

Usage

{
  "uSync": {
    "Settings": {
      "ImportAtStartup": "Settings",
      "IgnoreStopIfOnceExists": true
    }
  }
}

With this setting, deployments can include fresh usync.once files without removing old usync.stop files from disk.

Warning

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• www.myget.org
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Original prompt

---

This section details on the original issue you should resolve

<issue_title>Enhance usync.once/stop to support write only deployment</issue_title>
<issue_description>Hi,

We are using "write only" deploment (webdeploy without the option remove remote files first), and I can't find a way to use the usync.once / stop file.

My uSync configuration:

  "uSync": {
    "Settings": {
      "ExportOnSave": "None"
      "ImportAtStartup": "Settings",
      "StopFile": "../usync.stop",
      "OnceFile": "../usync.once"
    }
  },

1. I deploy the site first with a usync.once file
2. usync run the migration, and rename the file as "usync.stop"
3. I deploy the site a second time with a new usync.once file
4. usync ignore the file because there is a usync.stop file present

How could I handle this kind of deployment? I am sure I am not alone deploying using a write-only process.

I have a few suggestion to handle this case, when "ImportAtStartup" is set:

1. If a ".once" file is present, execute the import unconditionally, then rename or delete the .once file.
2. If a ".stop" file is present, skip the import
3. Else execute the import

This could be a breaking change if people have a deployment with the two files present (but it will only execute once).

The other option is to handle a new extension (which will cause the import to ignore the .stop for this extension only), or a new setting link "OnceHavePriority": true to enable the suggested behavior.

Thanks,</issue_description>

<agent_instructions>add a new setting called "IgnoreStopIfOnceExists" to resolve this issue, change the logic around the uSync during start-up to implement this change. </agent_instructions>

Comments on the Issue (you are @copilot in this section)

@KevinJump Hi,

Yes, I think, a new option like "OnceHavePriority" is probably the way we can go with this, its no breaking then, and shouldn't be too hard to add 🤞 </comment_new>

• Fixes Enhance usync.once/stop to support write only deployment #878

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[KevinJump]

Tested works as expected