Fix missing semi-colon in for loop and var body (#388)

We avoid adding a `;` for a variable declaration in for loop but this is only meant if the var declaration is inside of the `()` part of the for loop. Not if the body part.

Fixes #385

src/printer.js

@@ -746,17 +746,17 @@ function genericPrintNoParens(path, options, print) {
       ];
 
       // We generally want to terminate all variable declarations with a
-      // semicolon, except when they are children of for loops.
+      // semicolon, except when they in the () part of for loops.
       var parentNode = path.getParentNode();
 
-      if (
-        !namedTypes.ForStatement.check(parentNode) &&
-          !namedTypes.ForInStatement.check(parentNode) &&
-          !(namedTypes.ForOfStatement &&
-            namedTypes.ForOfStatement.check(parentNode)) &&
-          !(namedTypes.ForAwaitStatement &&
-            namedTypes.ForAwaitStatement.check(parentNode))
-      ) {
+      var isParentForLoop = namedTypes.ForStatement.check(parentNode) ||
+        namedTypes.ForInStatement.check(parentNode) |
+        (namedTypes.ForOfStatement &&
+          namedTypes.ForOfStatement.check(parentNode)) ||
+        (namedTypes.ForAwaitStatement &&
+          namedTypes.ForAwaitStatement.check(parentNode));
+
+      if (!(isParentForLoop && parentNode.body !== n)) {
         parts.push(";");
       }
 

tests/for/__snapshots__/jsfmt.spec.js.snap

@@ -291,3 +291,12 @@ for (var i = 0; i < 10; ++i) {
 }
 "
 `;
+
+exports[`test var.js 1`] = `
+"for (a in b) var c = {}; [];
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+for (a in b)
+  var c = {};
+[];
+"
+`;

tests/for/var.js

@@ -0,0 +1 @@
+for (a in b) var c = {}; [];