JS: Format if statements with no else on a single line

lib/src/js/printer.dart

Index: lib/src/js/printer.dart
diff --git a/lib/src/js/printer.dart b/lib/src/js/printer.dart
index 155ce854febd115c28cde134099c0378b465deba..a7de5939c2da7fc95d32c1ca83c6560ff7596e26 100644
--- a/lib/src/js/printer.dart
+++ b/lib/src/js/printer.dart
@@ -181,7 +181,16 @@ class Printer implements NodeVisitor {
 
   void outIndent(String str) { indent(); out(str); }
   void outIndentLn(String str) { indent(); outLn(str); }
+
+  bool _skipNextIndent = false;

[Jennifer Messerly, 2015/12/15 23:57:10]

style nit: it looks like they're keeping all fields up top.

[ochafik, 2015/12/16 02:00:37]

Done.

+  void skipNextIndent() {
+    _skipNextIndent = true;
+  }
   void indent() {
+    if (_skipNextIndent) {
+      _skipNextIndent = false;
+      return;
+    }
     if (!shouldCompressOutput) {
       out(indentation);
     }
@@ -299,8 +308,15 @@ class Printer implements NodeVisitor {
     visitNestedExpression(node.condition, EXPRESSION,
                           newInForInit: false, newAtStatementBegin: false);
     out(")");
-    bool thenWasBlock =
-        blockBody(then, needsSeparation: false, needsNewline: !hasElse);
+    bool thenWasBlock;

[Jennifer Messerly, 2015/12/15 23:57:10]

nice readability improvement.

Would it be possible to put this under a flag?

See JavaScriptPrintingOptions at the top of the file.

We can set this flag always in DDC. But this allows us to upstream the changes
to dart2js.

[ochafik, 2015/12/16 02:00:37]

Done (didn't realize the contamination potential :-))

+    if (!hasElse && then is! Block) {
+      thenWasBlock = false;
+      if (!shouldCompressOutput) spaceOut();

[Jennifer Messerly, 2015/12/15 23:57:10]

spaceOut() already does the shouldCompressOutput, so this can just be:

    spaceOut();

[ochafik, 2015/12/16 02:00:37]

D'oh!

+      skipNextIndent();
+      visit(then);
+    } else {
+      thenWasBlock = blockBody(then, needsSeparation: false, needsNewline: !hasElse);

[Jennifer Messerly, 2015/12/15 23:57:10]

long line

[ochafik, 2015/12/16 02:00:37]

Done.

+    }
     if (hasElse) {
       if (thenWasBlock) {
         spaceOut();