Provides contributors with a prompt to choose whether to overwrite, s… (#61)

* Provides contributors with a prompt to choose whether to overwrite, skip or abort
the rules overwrite necessary for running integration tests.

* Adds support for passing an optional command line flag to integration
test to specify whether Database rules should be overwritten or not.

Author: bojeil-google

test/integration/index.js

@@ -14,8 +14,22 @@
  * limitations under the License.
  */
 
+/**
+ * Runs Firebase Admin SDK integration tests.
+ * Usage:
+ * node index.js
+ * Where the following configuration files need to be provided:
+ * test/resources/key.json: The service account key file.
+ * test/resources/apikey.txt: The API key for the same project.
+ *
+ * Accepts an optional flag to specify whether to overwrite
+ * the specified project's Database rules or skip that step.
+ * node index.js --overwrite yes|skip
+ */
+
 var _ = require('lodash');
 var chalk = require('chalk');
+var readline = require('readline');
 
 var admin = require('../../lib/index');
 
@@ -78,6 +92,66 @@ utils.assert(
   'App instances do not match.'
 );
 
+/**
+ * Prompts the developer whether the Database rules should be
+ * overwritten with the relevant rules for the integration tests.
+ * The developer has 3 options:
+ * yes/y to agree to the rules overwrite.
+ * skip to skip the overwrite (rules already manually configured) and continue
+ * with the tests.
+ * no/n or other to abort.
+ * @param {*|undefined} overwrite An optional answer that can be provided to
+ *     bypass the need to prompt the user whether to proceed with, skip or abort
+ *     the Database rules overwrite.
+ * @return {Promise} A promise that resolves when the rules change is processed.
+ */
+function promptForUpdateRules(overwrite) {
+  return new Promise(function(resolve, reject) {
+    // Overwrite answer already provided.
+    if (typeof overwrite === 'string') {
+      resolve(overwrite);
+      return;
+    }
+    // Defines prompt interface.
+    var rl = readline.createInterface({
+      input: process.stdin,
+      output: process.stdout
+    });
+    // Options to display to end user.
+    var question = 'Warning: This test will overwrite your ';
+    question += 'project\'s existing Database rules.\n';
+    question += 'Overwrite Database rules for tests?\n';
+    // Yes to overwrite the rules.
+    question += '* \'yes\' to agree\n'
+    // Skip to continue without overwriting the rules.
+    question += '* \'skip\' to continue without the overwrite\n';
+    // No to cancel.
+    question += '* \'no\' to cancel\n';
+    // Prompt user with the 3 options.
+    rl.question(question, function(answer) {
+      rl.close();
+      // Resolve the promise with the answer.
+      resolve(answer);
+    });
+  })
+  .then(function(answer) {
+    switch (answer.toLowerCase()) {
+      case 'y':
+      case 'yes':
+        // Proceed and update the rules.
+        return updateRules();
+      case 'skip':
+        // Continue without updating the rules.
+        return Promise.resolve();
+      case 'no':
+      case 'n':
+      default:
+        // Abort and exit.
+        throw new Error('Integration test aborted!');
+    }
+  });
+}
+
 function updateRules() {
   // Update database rules to the defaults. Rest of the test suite
   // expects it.
@@ -96,8 +170,38 @@ function updateRules() {
     'PUT', defaultRules, headers, 10000);
 }
 
-return Promise.resolve()
-  .then(updateRules)
+/**
+ * Parses the script arguments and returns all the provided flags.
+ * @param {Array<string>} argv The process.argv list of script arguments.
+ * @return {Object} A key/value object with the provided script flags and
+ *     their values.
+ */
+function getScriptArguments(argv) {
+  // Dictionary of flags.
+  var flags = {};
+  var lastFlag = null;
+  // Skip first 2 arguments: node index.js
+  // Expected format: --flagA valueA --flagB --flagC valueC
+  for (var i = 2; i < argv.length; i++) {
+    if (argv[i].indexOf('--') === 0) {
+      // Get the last flag name.
+      lastFlag = argv[i].substr(2);
+      // If flag passed with no argument, set to true.
+      flags[lastFlag] = true;
+    } else if (lastFlag) {
+      // Argument provided for last flag, overwrite its value.
+      flags[lastFlag] = argv[i];
+      lastFlag = null;
+    } else {
+      // Value provided without a flag name.
+      throw new Error('Invalid script argument: "' + argv[i] + '"!');
+    }
+  }
+  return flags;
+}
+
+var flags = getScriptArguments(process.argv);
+return promptForUpdateRules(flags['overwrite'])
   .then(_.partial(app.test, utils))
   .then(_.partial(auth.test, utils))
   .then(_.partial(database.test, utils))