Phased rollout by country code; starting w/ desktop.stories remote flag

ts/test-both/RemoteConfig_test.ts

@@ -0,0 +1,97 @@
+// Copyright 2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import {
+  getCountryCodeValue,
+  getBucketValue,
+  innerIsBucketValueEnabled,
+} from '../RemoteConfig';
+
+describe('RemoteConfig', () => {
+  const uuid = '15b9729c-51ea-4ddb-b516-652befe78062';
+
+  describe('#innerIsBucketValueEnabled', () => {
+    // Note: bucketValue is 497941 for 'desktop.stories' key
+
+    it('returns true for 100% wildcard', () => {
+      assert.strictEqual(
+        innerIsBucketValueEnabled(
+          'desktop.stories',
+          '*:1000000',
+          '+12125550000',
+          uuid
+        ),
+        true
+      );
+    });
+
+    it('returns true for 50% on country code 1', () => {
+      assert.strictEqual(
+        innerIsBucketValueEnabled(
+          'desktop.stories',
+          '1:500000',
+          '+12125550000',
+          uuid
+        ),
+        true
+      );
+    });
+
+    it('returns false for 40% on country code 1', () => {
+      assert.strictEqual(
+        innerIsBucketValueEnabled(
+          'desktop.stories',
+          '1:400000',
+          '+12125550000',
+          uuid
+        ),
+        false
+      );
+    });
+  });
+
+  describe('#getCountryCodeValue', () => {
+    it('returns undefined for empty value', () => {
+      assert.strictEqual(getCountryCodeValue(1, '', 'flagName'), undefined);
+    });
+
+    it('throws for malformed flag', () => {
+      assert.throws(
+        () => getCountryCodeValue(1, 'hi:::', 'flagName'),
+        "invalid number ''"
+      );
+    });
+
+    it('throws for non-integer value', () => {
+      assert.throws(
+        () => getCountryCodeValue(1, '1:cd', 'flagName'),
+        "invalid number 'cd'"
+      );
+    });
+
+    it('returns wildcard value if no other codes', () => {
+      assert.strictEqual(getCountryCodeValue(1, '*:56,2:74', 'flagName'), 56);
+    });
+
+    it('returns value for specific codes, instead of wildcard', () => {
+      assert.strictEqual(getCountryCodeValue(1, '*:56,1:74', 'flagName'), 74);
+    });
+
+    it('returns undefined if no wildcard or specific value', () => {
+      assert.strictEqual(
+        getCountryCodeValue(1, '2:56,3:74', 'flagName'),
+        undefined
+      );
+    });
+  });
+
+  describe('#getBucketValue', () => {
+    it('returns undefined for empty value', () => {
+      const flagName = 'research.megaphone.1';
+
+      assert.strictEqual(getBucketValue(uuid, flagName), 243315);
+    });
+  });
+});