fix: proactively append to .gitignore during init (facebook#8028)

Author: bmuenzenmeyer

Diff for: packages/react-scripts/scripts/init.js

@@ -190,23 +190,20 @@ module.exports = function(
     }
   }
 
-  // Rename gitignore after the fact to prevent npm from renaming it to .npmignore
-  // See: https://github.com/npm/npm/issues/1862
-  try {
+  const gitignoreExists = fs.existsSync(path.join(appPath, '.gitignore'));
+  if (gitignoreExists) {
+    // Append if there's already a `.gitignore` file there
+    const data = fs.readFileSync(path.join(appPath, 'gitignore'));
+    fs.appendFileSync(path.join(appPath, '.gitignore'), data);
+    fs.unlinkSync(path.join(appPath, 'gitignore'));
+  } else {
+    // Rename gitignore after the fact to prevent npm from renaming it to .npmignore
+    // See: https://github.com/npm/npm/issues/1862
     fs.moveSync(
       path.join(appPath, 'gitignore'),
       path.join(appPath, '.gitignore'),
       []
     );
-  } catch (err) {
-    // Append if there's already a `.gitignore` file there
-    if (err.code === 'EEXIST') {
-      const data = fs.readFileSync(path.join(appPath, 'gitignore'));
-      fs.appendFileSync(path.join(appPath, '.gitignore'), data);
-      fs.unlinkSync(path.join(appPath, 'gitignore'));
-    } else {
-      throw err;
-    }
   }
 
   let command;