Remove extra line after directive with comment (#8536)

src/language-js/printer-estree.js

@@ -449,12 +449,17 @@ function printPathNoParens(path, options, print, args) {
 
       return concat(parts);
 
-    case "Program":
+    case "Program": {
+      const hasContents =
+        !n.body.every(({ type }) => type === "EmptyStatement") || n.comments;
+
       // Babel 6
       if (n.directives) {
-        path.each((childPath) => {
+        const directivesCount = n.directives.length;
+        path.map((childPath, index) => {
           parts.push(print(childPath), semi, hardline);
           if (
+            (index < directivesCount - 1 || hasContents) &&
             isNextLineEmpty(
               options.originalText,
               childPath.getValue(),
@@ -477,14 +482,12 @@ function printPathNoParens(path, options, print, args) {
       );
 
       // Only force a trailing newline if there were any contents.
-      if (
-        !n.body.every(({ type }) => type === "EmptyStatement") ||
-        n.comments
-      ) {
+      if (hasContents) {
         parts.push(hardline);
       }
 
       return concat(parts);
+    }
     // Babel extension.
     case "EmptyStatement":
       return "";

tests/js/directives/jsfmt.spec.js

@@ -1 +1,48 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+const { outdent } = require("outdent");
+
+run_spec(
+  {
+    dirname: __dirname,
+    snippets: [
+      {
+        code: outdent`
+          'use strict';
+
+          // comment
+        `,
+        output:
+          outdent`
+            "use strict";
+
+            // comment
+          ` + "\n",
+      },
+      {
+        code: outdent`
+          'use strict';
+          // comment
+        `,
+        output:
+          outdent`
+            "use strict";
+            // comment
+          ` + "\n",
+      },
+      {
+        code:
+          outdent`
+            'use strict';
+
+            // comment
+          ` + "\n",
+        output:
+          outdent`
+            "use strict";
+
+            // comment
+          ` + "\n",
+      },
+    ],
+  },
+  ["babel", "flow", "typescript"]
+);