Extract Privacy module

Centralizes how we redact sensitive information.

js/modules/privacy.js

@@ -0,0 +1,53 @@
+/* eslint-env node */
+
+const Path = require('path');
+
+const isString = require('lodash/isString');
+const compose = require('lodash/fp/compose');
+
+
+const PHONE_NUMBER_PATTERN = /\+\d{7,12}(\d{3})/g;
+const GROUP_ID_PATTERN = /(group\()([^)]+)(\))/g;
+
+const APP_ROOT_PATH = Path.join(__dirname, '..', '..', '..');
+const APP_ROOT_PATH_PATTERN = new RegExp(APP_ROOT_PATH, 'g');
+
+const REDACTION_PLACEHOLDER = '[REDACTED]';
+
+//      redactPhoneNumbers :: String -> String
+exports.redactPhoneNumbers = (text) => {
+  if (!isString(text)) {
+    throw new TypeError('`text` must be a string');
+  }
+
+  return text.replace(PHONE_NUMBER_PATTERN, `+${REDACTION_PLACEHOLDER}$1`);
+};
+
+//      redactGroupIds :: String -> String
+exports.redactGroupIds = (text) => {
+  if (!isString(text)) {
+    throw new TypeError('`text` must be a string');
+  }
+
+  return text.replace(
+    GROUP_ID_PATTERN,
+    (match, before, id, after) =>
+      `${before}${REDACTION_PLACEHOLDER}${id.slice(-3)}${after}`
+  );
+};
+
+//      redactSensitivePaths :: String -> String
+exports.redactSensitivePaths = (text) => {
+  if (!isString(text)) {
+    throw new TypeError('`text` must be a string');
+  }
+
+  return text.replace(APP_ROOT_PATH_PATTERN, REDACTION_PLACEHOLDER);
+};
+
+//      redactAll :: String -> String
+exports.redactAll = compose(
+  exports.redactSensitivePaths,
+  exports.redactGroupIds,
+  exports.redactPhoneNumbers
+);