From 7f9ee949eec2e9801372ac3263b025adf039e8aa Mon Sep 17 00:00:00 2001
From: Spencer Ahrens <sahrens@fb.com>
Date: Thu, 9 Apr 2015 17:49:20 -0700
Subject: [PATCH] [ReactNative] Don't redbox on flow config errors

---
 packager/getFlowTypeCheckMiddleware.js | 76 ++++++++++++++++++--------
 1 file changed, 54 insertions(+), 22 deletions(-)

diff --git a/packager/getFlowTypeCheckMiddleware.js b/packager/getFlowTypeCheckMiddleware.js
index e0f98bde2..312da45e2 100644
--- a/packager/getFlowTypeCheckMiddleware.js
+++ b/packager/getFlowTypeCheckMiddleware.js
@@ -8,8 +8,11 @@
  */
 'use strict';
 
+var chalk = require('chalk');
 var exec = require('child_process').exec;
 
+var hasWarned = {};
+
 function getFlowTypeCheckMiddleware(options) {
   return function(req, res, next) {
     if (options.skipflow) {
@@ -18,13 +21,19 @@ function getFlowTypeCheckMiddleware(options) {
     if (options.flowroot || options.projectRoots.length === 1) {
       var flowroot = options.flowroot || options.projectRoots[0];
     } else {
-      console.warn('flow: No suitable root');
+      if (!hasWarned.noRoot) {
+        hasWarned.noRoot = true;
+        console.warn('flow: No suitable root');
+      }
       return next();
     }
     exec('command -v flow >/dev/null 2>&1', function(error, stdout) {
       if (error) {
-        console.warn('flow: Skipping because not installed.  Install with ' +
-          '`brew install flow`.');
+        if (!hasWarned.noFlow) {
+          hasWarned.noFlow = true;
+          console.warn(chalk.yellow('flow: Skipping because not installed.  Install with ' +
+            '`brew install flow`.'));
+        }
         return next();
       } else {
         return doFlowTypecheck(res, flowroot, next);
@@ -36,10 +45,19 @@ function getFlowTypeCheckMiddleware(options) {
 function doFlowTypecheck(res, flowroot, next) {
   var flowCmd = 'cd "' + flowroot + '" && flow --json --timeout 20';
   var start = Date.now();
-  console.log('flow: Running static typechecks.');
-  exec(flowCmd, function(flowError, stdout) {
+  // Log start message if flow is slow to let user know something is happening.
+  var flowSlow = setTimeout(
+    function() {
+      console.log(chalk.gray('flow: Running static typechecks.'));
+    },
+    500
+  );
+  exec(flowCmd, function(flowError, stdout, stderr) {
+    clearTimeout(flowSlow);
     if (!flowError) {
-      console.log('flow: Typechecks passed (' + (Date.now() - start) + 'ms).');
+      console.log(chalk.gray(
+        'flow: Typechecks passed (' + (Date.now() - start) + 'ms).')
+      );
       return next();
     } else {
       try {
@@ -61,24 +79,38 @@ function doFlowTypecheck(res, flowroot, next) {
           });
           errorNum++;
         });
-        var message = 'Flow found type errors.  If you think these are wrong, ' +
-          'make sure flow is up to date, or disable with --skipflow.';
+        var error = {
+          status: 500,
+          message: 'Flow found type errors.  If you think these are wrong, ' +
+            'make sure your flow bin and .flowconfig are up to date, or ' +
+            'disable with --skipflow.',
+          type: 'FlowError',
+          errors: errors,
+        };
+        console.error(chalk.yellow('flow: Error running command `' + flowCmd +
+          '`:\n' + JSON.stringify(error))
+        );
+        res.writeHead(error.status, {
+          'Content-Type': 'application/json; charset=UTF-8',
+        });
+        res.end(JSON.stringify(error));
       } catch (e) {
-        var message =
-          'Flow failed to provide parseable output:\n\n`' + stdout + '`';
-        console.error(message, '\nException: `', e, '`\n\n');
+        if (stderr.match(/Could not find a \.flowconfig/)) {
+          if (!hasWarned.noConfig) {
+            hasWarned.noConfig = true;
+            console.warn(chalk.yellow('flow: ' + stderr));
+          }
+        } else {
+          if (!hasWarned.brokenFlow) {
+            hasWarned.brokenFlow = true;
+            console.warn(chalk.yellow(
+              'Flow failed to provide parseable output:\n\n`' + stdout +
+              '`.\n' + 'stderr: `' + stderr + '`'
+            ));
+          }
+        }
+        return next();
       }
-      var error = {
-        status: 500,
-        message: message,
-        type: 'FlowError',
-        errors: errors,
-      };
-      console.error('flow: Error running command `' + flowCmd + '`:\n', error);
-      res.writeHead(error.status, {
-        'Content-Type': 'application/json; charset=UTF-8',
-      });
-      res.end(JSON.stringify(error));
     }
   });
 }