From c09f3b62460a30ddb73c5f41a7321c1d3c3ae671 Mon Sep 17 00:00:00 2001
From: Alex Zherdev <alex.zherdev@gmail.com>
Date: Wed, 12 Sep 2018 22:10:25 -0700
Subject: [PATCH] Add tests for react version detection

---
 .gitignore                                    |  2 +-
 lib/util/version.js                           | 35 ++++++++++---------
 .../node_modules/react/index.js               |  5 +++
 .../node_modules/react/package.json           |  5 +++
 tests/util/version.js                         | 34 ++++++++++++++++++
 5 files changed, 64 insertions(+), 17 deletions(-)
 create mode 100644 tests/fixtures/version/detect-version/node_modules/react/index.js
 create mode 100644 tests/fixtures/version/detect-version/node_modules/react/package.json
 create mode 100644 tests/util/version.js

diff --git a/.gitignore b/.gitignore
index 4b8d368260..1568864758 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,7 +14,7 @@ pids
 logs
 reports
 build
-node_modules
+/node_modules
 npm-debug.log
 sftp-config.json
 
diff --git a/lib/util/version.js b/lib/util/version.js
index 87e87e5319..4aa472ccaa 100644
--- a/lib/util/version.js
+++ b/lib/util/version.js
@@ -9,27 +9,30 @@ const log = require('./log');
 
 let warnedForMissingVersion = false;
 
+function detectReactVersion() {
+  try {
+    const reactPath = resolve.sync('react', {basedir: process.cwd()});
+    const react = require(reactPath);
+    return react.version;
+  } catch (e) {
+    if (e.code === 'MODULE_NOT_FOUND') {
+      log('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.');
+      return '999.999.999';
+    }
+    throw e;
+  }
+}
+
 function getReactVersionFromContext(context) {
   let confVer = '999.999.999';
   // .eslintrc shared settings (http://eslint.org/docs/user-guide/configuring#adding-shared-settings)
   if (context.settings.react && context.settings.react.version) {
-    let settingsVer = context.settings.react.version;
-    if (settingsVer === 'detect') {
-      try {
-        const reactPath = resolve.sync('react', {basedir: process.cwd()});
-        const react = require(reactPath);
-        settingsVer = react.version;
-      } catch (e) {
-        if (e.code === 'MODULE_NOT_FOUND') {
-          log('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.');
-          settingsVer = '999.999.999';
-        } else {
-          throw e;
-        }
-      }
+    let settingsVersion = context.settings.react.version;
+    if (settingsVersion === 'detect') {
+      settingsVersion = detectReactVersion();
     }
-    confVer = settingsVer;
+    confVer = settingsVersion;
   } else if (!warnedForMissingVersion) {
     log('Warning: React version not specified in eslint-plugin-react settings. ' +
       'See https://github.com/yannickcr/eslint-plugin-react#configuration.');
diff --git a/tests/fixtures/version/detect-version/node_modules/react/index.js b/tests/fixtures/version/detect-version/node_modules/react/index.js
new file mode 100644
index 0000000000..022bb03217
--- /dev/null
+++ b/tests/fixtures/version/detect-version/node_modules/react/index.js
@@ -0,0 +1,5 @@
+'use strict';
+
+module.exports = {
+  version: '1.2.3'
+};
diff --git a/tests/fixtures/version/detect-version/node_modules/react/package.json b/tests/fixtures/version/detect-version/node_modules/react/package.json
new file mode 100644
index 0000000000..56d20a7d44
--- /dev/null
+++ b/tests/fixtures/version/detect-version/node_modules/react/package.json
@@ -0,0 +1,5 @@
+{
+  "name": "react",
+  "version": "1.2.3",
+  "main": "index.js"
+}
diff --git a/tests/util/version.js b/tests/util/version.js
new file mode 100644
index 0000000000..5112f8afcd
--- /dev/null
+++ b/tests/util/version.js
@@ -0,0 +1,34 @@
+/* eslint-env mocha */
+'use strict';
+
+const path = require('path');
+const assert = require('assert');
+const versionUtil = require('../../lib/util/version');
+
+describe('Version', () => {
+  const base = path.resolve(__dirname, '..', 'fixtures', 'version');
+  let cwd;
+
+  beforeEach(() => {
+    cwd = process.cwd();
+    process.chdir(base);
+  });
+
+  afterEach(() => {
+    process.chdir(cwd);
+  });
+
+  describe('Detect version', () => {
+    const context = {settings: {react: {version: 'detect'}}};
+
+    it('matches detected version', () => {
+      process.chdir('detect-version');
+      assert.equal(versionUtil.testReactVersion(context, '1.2.3'), true);
+      assert.equal(versionUtil.testReactVersion(context, '1.2.4'), false);
+    });
+
+    it('assumes latest version if react is not installed', () => {
+      assert.equal(versionUtil.testReactVersion(context, '999.999.999'), true);
+    });
+  });
+});