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

test/codegen/expect/unittest.js

 dart_library.library('unittest', null, /* Imports */[
   "dart/_runtime",
   'matcher/matcher',
   'dom/dom',
   'dart/core',
   'dart/async',
   'matcher/src/interfaces',
   'matcher/src/util',
   'matcher/src/description'
 ], /* Lazy imports */[
@@ skipping 36 matching lines @@
     constructors: () => ({TestFailure: [TestFailure, [core.String]]})
   });
   const ErrorFormatter = dart.typedef('ErrorFormatter', () => dart.functionType(core.String, [dart.dynamic, interfaces.Matcher, core.String, core.Map, core.bool]));
   function expect(actual, matcher, opts) {
     let reason = opts && 'reason' in opts ? opts.reason : null;
     let verbose = opts && 'verbose' in opts ? opts.verbose : false;
     let formatter = opts && 'formatter' in opts ? opts.formatter : null;
     matcher = util.wrapMatcher(matcher);
     let matchState = dart.map();
     try {
-      if (dart.notNull(dart.as(dart.dsend(matcher, 'matches', actual, matchState), core.bool)))
-        return;
+      if (dart.notNull(dart.as(dart.dsend(matcher, 'matches', actual, matchState), core.bool))) return;
     } catch (e) {
       let trace = dart.stackTrace(e);
       if (reason == null) {
         reason = `${typeof e == 'string' ? e : dart.toString(e)} at ${trace}`;
       }
     }
 
-    if (formatter == null)
-      formatter = _defaultFailFormatter;
+    if (formatter == null) formatter = _defaultFailFormatter;
     fail(dart.dcall(formatter, actual, matcher, reason, matchState, verbose));
   }
   dart.fn(expect, dart.void, [dart.dynamic, dart.dynamic], {reason: core.String, verbose: core.bool, formatter: ErrorFormatter});
   function fail(message) {
     return dart.throw(new TestFailure(message));
   }
   dart.fn(fail, dart.void, [core.String]);
   function _defaultFailFormatter(actual, matcher, reason, matchState, verbose) {
     let description = new description$.StringDescription();
     description.add('Expected: ').addDescriptionOf(matcher).add('\n');
     description.add('  Actual: ').addDescriptionOf(actual).add('\n');
     let mismatchDescription = new description$.StringDescription();
     matcher.describeMismatch(actual, mismatchDescription, matchState, verbose);
     if (dart.notNull(mismatchDescription.length) > 0) {
       description.add(`   Which: ${mismatchDescription}\n`);
     }
-    if (reason != null)
-      description.add(reason).add('\n');
+    if (reason != null) description.add(reason).add('\n');
     return dart.toString(description);
   }
   dart.fn(_defaultFailFormatter, core.String, [dart.dynamic, interfaces.Matcher, core.String, core.Map, core.bool]);
   // Exports:
   exports.group = group;
   exports.test = test;
   exports.TestFailure = TestFailure;
   exports.ErrorFormatter = ErrorFormatter;
   exports.expect = expect;
   exports.fail = fail;
 });