@cap-js-community/feature-toggle-library

Changed

• redis: migrate to @redis/client v6. Cluster read-modify-write now uses the built-in getNodeClientForKey() to obtain the node client owning a key's slot, replacing the manual slot calculation via cluster-key-slot (adopts fix for redis/node-redis#3194).

Added

• redis: add LOCAL_REDIS_CLUSTER integration mode, so cluster configuration is now detected locally as well.

Changed

• redis: expand tls handling to work with more cloud providers: SAP Cloud Infrastructure (SCI), Azure, GCP (contributed by @corporateuser)

Removed

• cds-plugin: removed legacy plugin activation support for @sap/cds before v7.3.0.

Changed

• core: switch from semaphore to execution-control re-use module.

Changed

• redis: migrate to @redis/client v5 with updated WATCH/MULTI/EXEC logic (fixes #114).

Fixed

• core: ignore mta blue-green deployment temporary appname suffixes -live and -idle (fixes #106).

Changed

• cds-plugin: rely on file neighborhood for service implementation resolution. This helps for scenarios where the server's model is shared with mtx/sidecar and a local implementation is not present.

Removed

• restrict to at least node v20.

Added

• enable voters for node v24.

Changed

• core: compatability changes for cds v9.

Added

• more testing for usage with cds.

⚠️ This release is potentially disruptive. Initialize will throw for previously ignored problems with configuration correctness. The coalesce logic for using multiple configuration sources has changed. For details see Layered Configuration.

Changed

• core: initialization throws if mandatory configuration fallbackValue is undefined (missing) or null (always invalid).

• core: initialization throws if mandatory configuration type is not in ["boolean", "number", "string"] (invalid).

• core: initialization throws if its invoked more than once. previously subsequent calls and their options were ignored.

• core: configuration reading and coalescing has changed:

  • up to v1.2.5, the order was runtime, files, auto, where the first occurrence is used for each toggle
  • from v1.3.0, the order is auto, files, runtime, where the last occurrence is used for each toggle
  • this enables overriding the configuration based on environmental factors, by mixing in dedicated config files

Fixed

• core: if a ./default-env.json file was present and NODE_ENV !== "production", we had assumed that cf env variables VCAP_APPLCATION and VCAP_SERVICES are always present in the file. now this is more resilient.

• core: [regression] initialize timing was noticeably slower, because the initial connection check was running with the default reconnect strategy that takes 2000ms. now the reconnect strategy is disabled for the initial connection check.

Changed

• cds-plugin: change default service access role to internal-user (fixes #90).
• redis: changed dependency from redis to @redis/client.

Added

• core: [undocumented] plugin-config/initialize support multiple configuration files.

• redis: [undocumented] cds-config/initialize take redis credentials and client options for fine-tuning or as an alternative to VCAP_SERVICES (brought up by #92).

  the cds-config approach is consistent with the redis integration of other cap-js-community projects, see event-queue, websocket.

Added

• cds-plugin: added explicit implementation for FeatureService.
• enable node v22 voters.

Fixed

• cds-plugin: allow feature toggles to initialize with no configured toggles.
• use proper cds syntax to get service operations (by johannes-vogel).

Changed

• the initialization log of the library will now show the unique name used. this name is used to derive both the redis storage key and pub/sub channel.

Fixed

• internal naming cleanup and consistency work.

Changed

• cds-plugin: service endpoint /rest/feature/redisRead will return server in-memory changes in NO_REDIS mode in order to be consistent with /rest/feature/redisUpdate.

Added

• cds-plugin: added cds.test() basic request/response tests for service.

Fixed

• cds-plugin: service endpoint /rest/feature/redisRead works without http errors in NO_REDIS mode.

⚠️ This release contains two minor breaking changes.

Changed

• The main class of the library is no longer explicitly exported. You can access it implicitly as constructor of the exported class instance.

  // before
  const { FeatureToggles } = require("@cap-js-community/feature-toggle-library");
  const myToggles = new FeatureToggles({ uniqueName: "snowflake" });
  
  // after
  const toggles = require("@cap-js-community/feature-toggle-library");
  const FeatureToggles = toggles.constructor;
  const myToggles = new FeatureToggles({ uniqueName: "snowflake" });

• cds-plugin: rewrote /rest/feature/redisRead endpoint to show all Redis maintained toggle values, including those of toggles that are not configured. The endpoint no longer refreshes the server-local toggle state. Consequently, it will work with read access privileges, since it can no longer modify the server-local state (fixes #69).

Added

• added remoteOnly option for /rest/feature/redisUpdate endpoint and the changeFeatureValue() API. With this option, you can clean up Redis maintained values that are no longer configured (fixes #69).
• cds-plugin: better detection of serve mode following changes in @sap/cds v8.2.3

Fixed

• multiple, even concurrent, calls of initializeFeatures() will only ever trigger one execution of the underlying initialization.

Fixed

• setting a root value with the option { clearSubScopes: true } only deleted the root and scoped values, but did not set the new root value.

Fixed

• cds-plugin: fix uniqueName configuration processing
• more consistent scope preference order when 2 out of 4 scopes are set

Changed

• fallback value null is no longer allowed (fixes #62).
• change handlers no longer receive null as new values, they get the actual new value for the relevant scope instead (fixes #64).

Fixed

• cds-plugin: unify and fix syntax of context.error and context.reject for cds service.
• change processing is more resilient. for redis message with multiple changes, if one change fails, then subsequent changes will still be processed.

Added

• docs: basic documentation for newest cds-plugin features.
• cds-plugin: better access control (fixes #57).

Fixed

• redis: better integration mode, will not log a connection error if redis is not present.

Added

• cds-plugin: fts feature toggles are detected and configured automatically (fixes #50).
• cds-plugin: allow custom scope map callback for fts feature toggles (fixes #51).
• cds-plugin: can configure unique name, i.e. which apps store the same toggles in redis, as part of cds configuration.

Fixed

• cds-plugin: feature toggles will not initialize during cds build.
• redis: proper usage of redis-client built-in reconnect capabilities.

Changed

• cds-service: always log update contents for traceability and improved logging for redis read and update errors.
• docs: add getting started section (fixes #43).

⚠️ User action required! This release will be more disruptive than usual. We re-thought that main require API and made it much leaner. These changes should have happened in 1.0, sorry for the inconvenience.

// before
const {
  singleton: { getFeatureValue },
} = require("@cap-js-community/feature-toggle-library");

function someFunc() {
  getFeatureValue(key);
}

// after
const toggles = require("@cap-js-community/feature-toggle-library");

function someFunc() {
  toggles.getFeatureValue(key);
}

For details see https://cap-js-community.github.io/feature-toggle-library/usage/

Changed

• the library now exports only the singleton instance (fixes #39).
• cds-plugin: the request header features are only respected in development environments (fixes #41).

We are releasing 1.0, after 2 years of continuous usage, testing, and small improvements.

Removed

• restrict to node v18+

Added

• act as Feature Vector Provider when used as a CDS-Plugin.
• allow graceful shutdown by closing redis clients on cds shutdown event (fixes #34).

Added

• support for redis cluster configurations.
• enable setting maximal log level through env variable BTP_FEATURES_LOG_LEVEL. this can be used to silence the library during tests.

Changed

• implement new CDS-Plugin API, where plugins export a promise instead of an activate property and stay compatible for older cds versions.

Fixed

• CDS-Plugin integration now works for projects that run cds build --production and only use the resulting csn.json at runtime.

Added

• new harmonized validation configuration for scope and regex checks, as well as external validation with user provided modules.

• new (optional) CDS-Plugin integration. for details, see the new plugin and service documentation.

• new logger implementation which replaces cf-nodejs-logging-support dependency. it has better cds integration (if present). for example, it will log correlation ids that are present in cds context via async local storage.

Changed

• allowedScopes: [xxx] configuration will now be ignored and needs to be replaced with validations: [{ scopes: [xxx] }].

• validation: yyy configuration will now be ignored and needs to be replaced with validations: [{ regex: yyy }].

Fixed

• re-work pipelines to separate main branch and pr-voter status

Added

• example http request file for example-cap-server

Fixed

• better documentation regarding scoping and redis hash map persistence

• more resilient handling of bad input for scopeMaps in all external APIs

Added

• first public release on npmjs

Added

• added allowedScopes configuration, which validates that correct scope names are used for updates

Fixed

• separate rootValue from other scopedValues in getFeatureInfo and getFeaturesInfos APIs

Added

• added example-cap-server code, that acts both as an example integration code into existing cap projects and as a starting point for manual testing

Fixed

• first iteration towards updating documentation

Fixed

• fix bug where scoped values were ignored if they are falsy

Added

• simple migration for old sting-type state to hash-type persistence state

Fixed

• fix redis transaction re-writes

Removed

• remove API to read feature config and metadata getFeatureConfig and getFeatureConfigs. use getFeatureInfo and getFeaturesInfos instead

Added

• new option to add scope restrictions when reading or setting feature toggles

• separate persistence on redis using HGET, HSET, so that individual toggle changes don't have to touch the state of all feature toggles. effectively we change the redis type for the persistence key from string to hash.

• new API getFeatureInfo and getFeaturesInfos to get all config and state information in one call

Fixed

• rewrite to improve config handling internally

• fix some problems with the logger in combination with verror

Removed

• restrict to node v16+

Added

• new interface to get main and subscriber client in redis wrapper

Fixed

• better coding and interface for LazyCache and ExpiringLazyCache

• more and improved jsdocs

• allow options to be passed in redis wrapper set implementation. see SET for details.

Fixed

• make logging for warn level work properly

Fixed

• re-work logging approach so structured logging will capture VError info

Fixed

• update feature value is now exclusive under high concurrency (semaphore implementation by oklemenz2)

• prettier and documentation work better together

Added

• users can rely on always getting fallback value

Added

• local integration tests

• write own env implementation replacing @sap/xsenv dependency

Fixed

• more fixes related to error event handling in local case after redis library v4 migration

Removed

• restrict to node v12+

Fixed

• fix mainClient and subscriberClient reference handling in error case

Fixed

• migrate redis dependency to v4

Added

• allow to set singleton uniqueName via env variable BTP_FEATURES_UNIQUE_NAME

Fixed

• fix readConfigFromFile for yaml case

Removed

• config property enabled is discontinued, use active instead

Added

• new config property: active. if active is set to false, no changes of the feature toggle is allowed, but old value stays in place

• new API to read feature config and metadata getFeatureConfig and getFeatureConfigs

Fixed

• change interface name readConfigFromFilepath to readConfigFromFile

• change signature for FeatureValueChangeHandler to handler(newValue, oldValue)

Fixed

• change external validators interface to allow reporting multiple errors

Fixed

• change validator return interface to ValidationErrors for consistency

Fixed

• make singleton more IDE friendly and ensure correctness with test

• switch to artifactory registry

Added

• feature: external validation

Fixed

• readme update

• handler name fallback for anonymous functions

• inputValidation is now async to account for potentially async external validators

Added

• Initial public release