rollup.config.jsの拡張子を.mjsに変更

default.nix

@@ -17,7 +17,7 @@ pkgs.stdenv.mkDerivation rec {
 
   buildPhase=''
     HOME=$TMP yarn install --frozen-lockfile
-    yarn rollup --config ./rollup.config.js
+    yarn rollup --config ./rollup.config.mjs
     cp ./package.json ./README.md ./dist
     cd ./dist
     yarn pack

dist/index.d.ts

@@ -0,0 +1,47 @@
+import type { Driver } from '@cycle/run';
+import type { Decoder } from 'io-ts/Decoder';
+import * as LaunchDarkly from 'launchdarkly-js-client-sdk';
+import { type MemoryStream, Stream } from 'xstream';
+declare type Dictionary = Readonly<{
+    [_: string]: unknown;
+}>;
+export interface FeaturesSource<Features extends Dictionary> {
+    readonly stream: MemoryStream<Features>;
+}
+declare type LDParams = Parameters<typeof LaunchDarkly.initialize>;
+export declare type Params<Features extends Dictionary> = Readonly<{
+    /**
+     * The decoder for the feature flags.
+     */
+    decoder: Decoder<unknown, Features>;
+    /**
+     * The default values of the feature flags.
+     */
+    defaultValues: Features;
+    /**
+     * The client-side ID.
+     */
+    envKey: LDParams[0];
+    /**
+     * When the LaunchDarkly client initialization exceeds this duration, the default values will be emitted to the sink.
+     * In milliseconds.
+     */
+    fallbackDelay?: number | undefined;
+    /**
+     * Optional configuration settings.
+     */
+    options?: LDParams[2];
+    /**
+     * The initial user properties.
+     */
+    user: LDParams[1];
+}>;
+/**
+ * A factory function for the LaunchDarkly driver.
+ */
+export declare function makeLaunchDarklyDriver<Features extends Dictionary>({ decoder, defaultValues, envKey, fallbackDelay, options, user, }: Params<Features>): Driver<void, FeaturesSource<Features>>;
+/**
+ * A factory function to create a mocked `FeaturesSource`, for testing purposes.
+ */
+export declare function makeMockFeaturesDriver<Features extends Dictionary>($: Stream<Features>): Driver<void, FeaturesSource<Features>>;
+export {};

dist/index.js

@@ -0,0 +1,68 @@
+import * as E from 'fp-ts/Either';
+import { pipe } from 'fp-ts/function';
+import * as LaunchDarkly from 'launchdarkly-js-client-sdk';
+import { Stream } from 'xstream';
+import delay from 'xstream/extra/delay';
+
+function makeClient$(...[envKey, user, options]) {
+    let client;
+    return Stream.create({
+        start: (listener) => {
+            client = LaunchDarkly.initialize(envKey, user, options);
+            void client.waitForInitialization().then(() => {
+                if (client === undefined) {
+                    return;
+                }
+                listener.next(client);
+            });
+        },
+        stop: () => {
+            void client?.close();
+            client = undefined;
+        },
+    });
+}
+/**
+ * A factory function for the LaunchDarkly driver.
+ */
+function makeLaunchDarklyDriver({ decoder, defaultValues, envKey, fallbackDelay = 0, options, user, }) {
+    const client$ = makeClient$(envKey, user, options);
+    const $ = client$.map((client) => {
+        let onNext;
+        let onError;
+        return Stream.create({
+            start(listener) {
+                onNext = () => {
+                    const allFlags = client.allFlags();
+                    const flags = decoder.decode(allFlags);
+                    const action = pipe(flags, E.fold(() => () => options?.logger?.warn(`Failed to decode the flags: ${JSON.stringify(allFlags)}`), (flags) => () => {
+                        listener.next(flags);
+                    }));
+                    action();
+                };
+                onError = listener.error;
+                client.on('change', onNext);
+                client.on('error', listener.error);
+                client.on('failed', listener.error);
+                onNext();
+            },
+            stop() {
+                client.off('change', onNext);
+                client.off('error', onError);
+                client.on('failed', onError);
+            },
+        });
+    });
+    const defaultValues$ = Stream.of(defaultValues).compose(delay(fallbackDelay));
+    return () => ({
+        stream: $.startWith(defaultValues$).flatten(),
+    });
+}
+/**
+ * A factory function to create a mocked `FeaturesSource`, for testing purposes.
+ */
+function makeMockFeaturesDriver($) {
+    return () => ({ stream: $ });
+}
+
+export { makeLaunchDarklyDriver, makeMockFeaturesDriver };