From 0324675c3ac1ad369d1c1f2902ba5f3b8b213856 Mon Sep 17 00:00:00 2001
From: Ju Liu <ju@noredink.com>
Date: Thu, 15 Oct 2020 17:22:00 +0100
Subject: [PATCH 1/2] Make diff include which are the files we are comparing

---
 test/run.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/run.sh b/test/run.sh
index 00fb935c0..7486b7b39 100755
--- a/test/run.sh
+++ b/test/run.sh
@@ -42,7 +42,7 @@ function runCommandAndCompareToSnapshot {
         echo -e "\n    \e[31mbut got:\e[0m\n"
         cat "$TMP/$FILE"
         echo -e "\n    \e[31mHere is the difference:\e[0m\n"
-        diff "$TMP/$FILE" "$SNAPSHOTS/$FILE"
+        diff -p "$TMP/$FILE" "$SNAPSHOTS/$FILE"
         exit 1
     else
       echo -e "  \e[92mOK\e[0m"

From 0c4c68ffb2ff440dd26fbdc8fc98b9b85ed5c8b4 Mon Sep 17 00:00:00 2001
From: Ju Liu <ju@noredink.com>
Date: Thu, 15 Oct 2020 17:21:40 +0100
Subject: [PATCH 2/2] Ensure we finish writing the report to stdout

---
 lib/report.js     | 48 +++++++++++++++++++++++++++++++++++------------
 lib/run-review.js |  2 +-
 lib/runner.js     | 11 ++++++-----
 3 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/lib/report.js b/lib/report.js
index bb17b712b..e292ff172 100644
--- a/lib/report.js
+++ b/lib/report.js
@@ -2,7 +2,7 @@ const styledMessage = require('./styled-message');
 
 module.exports = report;
 
-function report(options, result) {
+async function report(options, result) {
   if (options.report === 'json') {
     return print(options, jsonReport(result.errors));
   }
@@ -22,22 +22,46 @@ function jsonReport(errors) {
 function print(options, json) {
   if (options.reportOnOneLine) {
     if (json.type === 'review-errors') {
-      json.errors.forEach((errorForFile) => {
-        errorForFile.errors.forEach((error) => {
-          console.log(
-            JSON.stringify({
-              path: errorForFile.path,
-              ...error
+      if (json.errors.length > 0) {
+        return safeConsoleLog(
+          json.errors
+            .map((errorForFile) => {
+              return errorForFile.errors
+                .map((error) => {
+                  return JSON.stringify({
+                    path: errorForFile.path,
+                    ...error
+                  });
+                })
+                .join('\n');
             })
-          );
-        });
-      });
+            .join('\n')
+        );
+      }
     } else {
-      console.log(JSON.stringify(json));
+      return safeConsoleLog(JSON.stringify(json));
     }
   } else {
-    console.log(
+    return safeConsoleLog(
       JSON.stringify(json, null, options.debug || options.forTests ? 2 : 0)
     );
   }
 }
+
+// Printing large outputs to stdout is not recommended because at times
+// console.log is asynchronous and returns before ensuring that the whole
+// output has been printed. Check out these links for more details:
+//
+// - https://nodejs.org/api/process.html#process_process_exit_code
+// - https://github.com/nodejs/node/issues/6456
+// - https://github.com/nodejs/node/issues/19218
+//
+// Using process.stdout.write and passing a function ensures that
+// the whole output has been written.
+function safeConsoleLog(message) {
+  return new Promise((resolve) => {
+    process.stdout.write(message + '\n', () => {
+      resolve();
+    });
+  });
+}
diff --git a/lib/run-review.js b/lib/run-review.js
index 53726d79a..9cf1feb41 100644
--- a/lib/run-review.js
+++ b/lib/run-review.js
@@ -23,7 +23,7 @@ async function runReview(options, app) {
   });
   Benchmark.end(options, 'review');
 
-  report(options, result);
+  await report(options, result);
 
   return result.success;
 }
diff --git a/lib/runner.js b/lib/runner.js
index ea6db0d8b..136192242 100755
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -76,11 +76,12 @@ async function initializeApp(options, elmModulePath, reviewElmJson) {
   autofix.subscribe(options, app);
   if (options.watch) {
     AppState.subscribe(app.ports.reviewReport, (result) => {
-      report(options, result);
-      const shouldReReview = AppState.reviewFinished();
-      if (shouldReReview) {
-        return startReview(options, app);
-      }
+      return report(options, result).then(() => {
+        const shouldReReview = AppState.reviewFinished();
+        if (shouldReReview) {
+          return startReview(options, app);
+        }
+      });
     });
   }