38 lines
1.9 KiB
Markdown
38 lines
1.9 KiB
Markdown
# Implementing experimental features in Synapse
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It can be desirable to implement "experimental" features which are disabled by
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default and must be explicitly enabled via the Synapse configuration. This is
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applicable for features which:
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* Are unstable in the Matrix spec (e.g. those defined by an MSC that has not yet been merged).
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* Developers are not confident in their use by general Synapse administrators/users
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(e.g. a feature is incomplete, buggy, performs poorly, or needs further testing).
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Note that this only really applies to features which are expected to be desirable
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to a broad audience. The [module infrastructure](../modules/index.md) should
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instead be investigated for non-standard features.
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Guarding experimental features behind configuration flags should help with some
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of the following scenarios:
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* Ensure that clients do not assume that unstable features exist (failing
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gracefully if they do not).
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* Unstable features do not become de-facto standards and can be removed
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aggressively (since only those who have opted-in will be affected).
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* Ease finding the implementation of unstable features in Synapse (for future
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removal or stabilization).
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* Ease testing a feature (or removal of feature) due to enabling/disabling without
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code changes. It also becomes possible to ask for wider testing, if desired.
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Experimental configuration flags should be disabled by default (requiring Synapse
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administrators to explicitly opt-in), although there are situations where it makes
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sense (from a product point-of-view) to enable features by default. This is
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expected and not an issue.
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It is not a requirement for experimental features to be behind a configuration flag,
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but one should be used if unsure.
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New experimental configuration flags should be added under the `experimental`
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configuration key (see the `synapse.config.experimental` file) and either explain
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(briefly) what is being enabled, or include the MSC number.
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