Ignore empty statement in switch newline detection (#1220)

Fixes #1200

src/printer.js

@@ -1189,12 +1189,17 @@ function genericPrintNoParens(path, options, print, args) {
         const cons = path.call(consequentPath => {
           return join(
             hardline,
-            consequentPath.map((p, i) => {
+            consequentPath
-              const shouldAddLine =
+              .map((p, i) => {
-                i !== n.consequent.length - 1 &&
+                if (n.consequent[i].type === "EmptyStatement") {
-                util.isNextLineEmpty(options.originalText, p.getValue());
+                  return null;
-              return concat([print(p), shouldAddLine ? hardline : ""]);
+                }
-            })
+                const shouldAddLine =
+                  i !== n.consequent.length - 1 &&
+                  util.isNextLineEmpty(options.originalText, p.getValue());
+                return concat([print(p), shouldAddLine ? hardline : ""]);
+              })
+              .filter(e => e !== null)
           );
         }, "consequent");
         parts.push(

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

@@ -48,6 +48,12 @@ switch (x) {
 
     break;
 }
+
+switch (a) {
+  case b:
+    if (1) {};
+    c;
+}
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 switch (foo) {
   case "bar":
@@ -93,6 +99,13 @@ switch (x) {
     break;
 }
 
+switch (a) {
+  case b:
+    if (1) {
+    }
+    c;
+}
+
 `;
 
 exports[`empty_switch.js 1`] = `

tests/switch/empty_lines.js

@@ -45,3 +45,9 @@ switch (x) {
 
     break;
 }
+
+switch (a) {
+  case b:
+    if (1) {};
+    c;
+}