Prevent adding softline after arrow attribute with comments (#3641)

* failing test

* fix

src/language-js/printer-estree.js

@@ -499,8 +499,9 @@ function printPathNoParens(path, options, print, args) {
       // with the opening (, or if it's inside a JSXExpression (e.g. an attribute)
       // we should align the expression's closing } with the line with the opening {.
       const shouldAddSoftLine =
-        (args && args.expandLastArg) ||
-        path.getParentNode().type === "JSXExpressionContainer";
+        ((args && args.expandLastArg) ||
+          path.getParentNode().type === "JSXExpressionContainer") &&
+        !(n.comments && n.comments.length);
 
       const printTrailingComma =
         args && args.expandLastArg && shouldPrintComma(options, "all");

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

@@ -12,6 +12,13 @@ exports[`attr-comments.js 1`] = `
     // comment
     arg => fn(arg)
   }
+  propArrowWithBreak={
+    // comment
+    arg =>
+      fn({
+        makeItBreak
+      })
+  }
   propArray={
     // comment
     [el1, el2]
@@ -37,6 +44,13 @@ exports[`attr-comments.js 1`] = `
     // comment
     arg => fn(arg)
   }
+  propArrowWithBreak={
+    // comment
+    arg =>
+      fn({
+        makeItBreak
+      })
+  }
   propArray={
     // comment
     [el1, el2]

tests/jsx/attr-comments.js

@@ -9,6 +9,13 @@
     // comment
     arg => fn(arg)
   }
+  propArrowWithBreak={
+    // comment
+    arg =>
+      fn({
+        makeItBreak
+      })
+  }
   propArray={
     // comment
     [el1, el2]