Repository: jlongster/prettier (js)
Issue: Newline after "use strict" on babylon
This may be one of those personal taste issues, but I prefer to leave a newline between the `"use strict"` statement and any imports. It seems to create the same rhythm as leaving newlines between function definitions and import groups (I group by system, vendor, internal).
Pull request description: Preserve new lines after directives in babylon
It's annoying that the line after `"use strict";` gets eaten away on babylon. This fixes it :)

Fixes #216

Patch:
diff --git a/src/printer.js b/src/printer.js
index 28990dde8..93aae542d 100644
--- a/src/printer.js
+++ b/src/printer.js
@@ -115,6 +115,9 @@ function genericPrintNoParens(path, options, print) {
         path.each(
           function(childPath) {
             parts.push(print(childPath), ";", hardline);
+            if (util.newlineExistsAfter(options.originalText, util.locEnd(childPath.getValue()))) {
+              parts.push(hardline);
+            }
           },
           "directives"
         );
@@ -627,7 +630,7 @@ function genericPrintNoParens(path, options, print) {
                   indent(options.tabWidth, concat([softline, printedValue]))
                 ])
               ),
-              line,
+              softline,
               ifBreak(")")
             ])
           );


Test patch:
diff --git a/tests/directives/__snapshots__/jsfmt.spec.js.snap b/tests/directives/__snapshots__/jsfmt.spec.js.snap
index f680d0532..b63c61eb4 100644
--- a/tests/directives/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/directives/__snapshots__/jsfmt.spec.js.snap
@@ -1,3 +1,40 @@
+exports[`test newline.js 1`] = `
+"/* @flow */
+
+\"use strict\";
+
+import a from \"a\";
+
+a();
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/* @flow */
+
+\"use strict\";
+
+import a from \"a\";
+
+a();
+"
+`;
+
+exports[`test newline.js 2`] = `
+"/* @flow */
+
+\"use strict\";
+
+import a from \"a\";
+
+a();
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/* @flow */
+\"use strict\";
+
+import a from \"a\";
+
+a();
+"
+`;
+
 exports[`test test.js 1`] = `
 "\"use strict\";
 
@@ -12,3 +49,18 @@ function fn() {
 }
 "
 `;
+
+exports[`test test.js 2`] = `
+"\"use strict\";
+
+function fn() {
+  \"use strict\";
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+\"use strict\";
+
+function fn() {
+  \"use strict\";
+}
+"
+`;
diff --git a/tests/directives/jsfmt.spec.js b/tests/directives/jsfmt.spec.js
index 989047bcc..d5ec770a9 100644
--- a/tests/directives/jsfmt.spec.js
+++ b/tests/directives/jsfmt.spec.js
@@ -1,1 +1,2 @@
 run_spec(__dirname);
+run_spec(__dirname, {parser: 'babylon'});
diff --git a/tests/directives/newline.js b/tests/directives/newline.js
new file mode 100644
index 000000000..8da10321b
--- /dev/null
+++ b/tests/directives/newline.js
@@ -0,0 +1,7 @@
+/* @flow */
+
+"use strict";
+
+import a from "a";
+
+a();
diff --git a/tests/flow/logical/__snapshots__/jsfmt.spec.js.snap b/tests/flow/logical/__snapshots__/jsfmt.spec.js.snap
index f3cab28a7..2ff1eac92 100644
--- a/tests/flow/logical/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/flow/logical/__snapshots__/jsfmt.spec.js.snap
@@ -901,14 +901,14 @@ function logical12b(y: number): number {
  */
 function logical13(x: number): Array<{ x: string }> {
   return [
-    { x: x && \"bar\"  },
-    { x: true && \"bar\"  },
-    { x: true && false  },
-    { x: false && false  },
-    { x: 1 && \"bar\"  },
-    { x: \"foo\" && \"bar\"  },
-    { x: \"foo\" && \"bar\"  },
-    { x: \"foo\" && \"bar\"  }
+    { x: x && \"bar\" },
+    { x: true && \"bar\" },
+    { x: true && false },
+    { x: false && false },
+    { x: 1 && \"bar\" },
+    { x: \"foo\" && \"bar\" },
+    { x: \"foo\" && \"bar\" },
+    { x: \"foo\" && \"bar\" }
   ];
 }
 
@@ -917,14 +917,14 @@ function logical13(x: number): Array<{ x: string }> {
  */
 function logical14(x: number): Array<{ x: string }> {
   return [
-    { x: x || \"bar\"  },
-    { x: false || \"bar\"  },
-    { x: false || true  },
-    { x: true || false  },
-    { x: 0 || \"bar\"  },
-    { x: \"foo\" || \"bar\"  },
-    { x: \"foo\" || \"bar\"  },
-    { x: \"foo\" || \"bar\"  }
+    { x: x || \"bar\" },
+    { x: false || \"bar\" },
+    { x: false || true },
+    { x: true || false },
+    { x: 0 || \"bar\" },
+    { x: \"foo\" || \"bar\" },
+    { x: \"foo\" || \"bar\" },
+    { x: \"foo\" || \"bar\" }
   ];
 }
 
diff --git a/tests/trailing_comma/__snapshots__/jsfmt.spec.js.snap b/tests/trailing_comma/__snapshots__/jsfmt.spec.js.snap
index d6a325b0a..b03422f52 100644
--- a/tests/trailing_comma/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/trailing_comma/__snapshots__/jsfmt.spec.js.snap
@@ -77,6 +77,11 @@ const aLong = {
   },
   dHasALongName: \'a-long-value-too\'
 };
+
+const aLong = {
+  dHasALongName: \'a-long-value-too\',
+  eHasABooleanExpression: a === a,
+};
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 const a = { b: true, c: { c1: \"hello\" }, d: false };
 
@@ -88,6 +93,11 @@ const aLong = {
   },
   dHasALongName: \"a-long-value-too\"
 };
+
+const aLong = {
+  dHasALongName: \"a-long-value-too\",
+  eHasABooleanExpression: a === a
+};
 "
 `;
 
@@ -108,6 +118,11 @@ const aLong = {
   },
   dHasALongName: \'a-long-value-too\'
 };
+
+const aLong = {
+  dHasALongName: \'a-long-value-too\',
+  eHasABooleanExpression: a === a,
+};
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 const a = { b: true, c: { c1: \"hello\" }, d: false };
 
@@ -119,5 +134,10 @@ const aLong = {
   },
   dHasALongName: \"a-long-value-too\",
 };
+
+const aLong = {
+  dHasALongName: \"a-long-value-too\",
+  eHasABooleanExpression: a === a,
+};
 "
 `;
diff --git a/tests/trailing_comma/object.js b/tests/trailing_comma/object.js
index 9bdc3b1f2..10c074ca9 100644
--- a/tests/trailing_comma/object.js
+++ b/tests/trailing_comma/object.js
@@ -14,3 +14,8 @@ const aLong = {
   },
   dHasALongName: 'a-long-value-too'
 };
+
+const aLong = {
+  dHasALongName: 'a-long-value-too',
+  eHasABooleanExpression: a === a,
+};