Fix git init race condition (#3877)

packages/react-scripts/scripts/init.js

@@ -40,7 +40,7 @@ function insideMercurialRepository() {
   }
 }
 
-function gitInit() {
+function tryGitInit() {
   try {
     execSync('git --version', { stdio: 'ignore' });
 
@@ -114,23 +114,22 @@ module.exports = function(
 
   // Rename gitignore after the fact to prevent npm from renaming it to .npmignore
   // See: https://github.com/npm/npm/issues/1862
-  fs.move(
-    path.join(appPath, 'gitignore'),
-    path.join(appPath, '.gitignore'),
-    [],
-    err => {
-      if (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;
-        }
-      }
+  try {
+    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;
   let args;
@@ -173,8 +172,9 @@ module.exports = function(
     }
   }
 
-  if (gitInit()) {
-    console.log('Initialized git repository');
+  if (tryGitInit()) {
+    console.log();
+    console.log('Initialized a git repository.');
   }
 
   // Display the most elegant way to cd.