Continuous integration

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A snapshot that changes on a build server is a failure to report, not source code to rewrite. Inline snapshots are therefore never updated, and no merge tool is started, in these environments, whatever the update strategy, including Overwrite and a strategy set with INLINESNAPSHOTTESTING_STRATEGY:

A build server or another non-interactive environment, detected by the variables the major build servers set (CI, TF_BUILD, GITHUB_ACTION, GITLAB_CI, JENKINS_URL, TEAMCITY_VERSION, ...). Containers and WSL are treated the same way, as no diff tool is expected to show up there.
A continuous testing runner: NCrunch, ReSharper or Visual Studio Live Unit Testing.
An LLM agent, such as Claude Code, Codex, GitHub Copilot or Cursor. An agent that runs the tests sees the failure and the difference, and does not get its source files rewritten behind its back.

The test fails as with Disallow, and the failure message says which environment was detected. The detection is the same as for file snapshots; see Continuous integration in SnapshotTesting for the full list of variables.

Allow updates in such an environment

To allow updates anyway, for instance in a dev container where you run the tests yourself, set the INLINESNAPSHOTTESTING_AUTODETECT_CONTINUOUS_ENVIRONMENT environment variable to false (or 0, no, off), or set AutoDetectContinuousEnvironment to false:

InlineSnapshot
    .WithSettings(settings => settings.AutoDetectContinuousEnvironment = false)
    .Validate(new { Name = "meziantou" }, "Name: meziantou");

The update strategy then applies as on a developer machine.