From f59e927405f2dacd897df69661dba0305ecad03c Mon Sep 17 00:00:00 2001
From: abhishekdev <227926+abhishekdev@users.noreply.github.com>
Date: Fri, 28 Jun 2019 14:35:39 -0400
Subject: [PATCH 1/2] version detection: Add tests

- Warn only once for failure to detect react version

Ref: #2276
---
 tests/util/version.js | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/util/version.js b/tests/util/version.js
index 5eacb4633f..ea8a09b490 100644
--- a/tests/util/version.js
+++ b/tests/util/version.js
@@ -44,6 +44,15 @@ describe('Version', () => {
       ];
     });
 
+    it('warns only once for failure to detect react ', () => {
+      assert.equal(versionUtil.testReactVersion(context, '999.999.999'), true);
+      assert.equal(versionUtil.testReactVersion(context, '999.999.999'), true);
+
+      expectedErrorArgs = [
+        ['Warning: React version was set to "detect" in eslint-plugin-react settings, but the "react" package is not installed. Assuming latest React version for linting.']
+      ];
+    });
+
     it('assumes latest version if flow-bin is not installed', () => {
       assert.equal(versionUtil.testFlowVersion(context, '999.999.999'), true);
 

From 8fbf50c142ed9710b57830faa92ef2f6460ef8c3 Mon Sep 17 00:00:00 2001
From: abhishekdev <227926+abhishekdev@users.noreply.github.com>
Date: Fri, 28 Jun 2019 14:35:49 -0400
Subject: [PATCH 2/2] version detection: Do not throw a raw error after the
 first warning

- Adjust the conditions to always assume a latest react version when e.code === 'MODULE_NOT_FOUND'
- The `warnedForMissingVersion` flag only controls the warning message and not the handling of the error

Ref: #2276
---
 lib/util/version.js | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/util/version.js b/lib/util/version.js
index 3e8af90c01..932866bc69 100644
--- a/lib/util/version.js
+++ b/lib/util/version.js
@@ -20,10 +20,12 @@ function detectReactVersion() {
     const react = require(reactPath); // eslint-disable-line import/no-dynamic-require
     return react.version;
   } catch (e) {
-    if (!warnedForMissingVersion && e.code === 'MODULE_NOT_FOUND') {
-      error('Warning: React version was set to "detect" in eslint-plugin-react settings, ' +
+    if (e.code === 'MODULE_NOT_FOUND') {
+      if (!warnedForMissingVersion) {
+        error('Warning: React version was set to "detect" in eslint-plugin-react settings, ' +
         'but the "react" package is not installed. Assuming latest React version for linting.');
-      warnedForMissingVersion = true;
+        warnedForMissingVersion = true;
+      }
       return '999.999.999';
     }
     throw e;