util: fix formatting of objects with SIMD enabled

When SIMD is enabled, `util.format` couldn’t display objects
(with at least 1 key) because the formatter function got
overridden.

PR-URL: https://github.com/nodejs/node/pull/7864
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <mic.besace@gmail.com>

lib/util.js

@@ -487,16 +487,13 @@ function formatValue(ctx, value, recurseTimes) {
                    'byteOffset',
                    'buffer');
     }
-  } else if (simdFormatters &&
-             typeof value.constructor === 'function' &&
-             (formatter = simdFormatters.get(value.constructor))) {
-    braces = ['[', ']'];
   } else {
     var promiseInternals = inspectPromise(value);
     if (promiseInternals) {
       braces = ['{', '}'];
       formatter = formatPromise;
     } else {
+      let maybeSimdFormatter;
       if (binding.isMapIterator(value)) {
         constructor = { name: 'MapIterator' };
         braces = ['{', '}'];
@@ -507,6 +504,11 @@ function formatValue(ctx, value, recurseTimes) {
         braces = ['{', '}'];
         empty = false;
         formatter = formatCollectionIterator;
+      } else if (simdFormatters &&
+                 typeof constructor === 'function' &&
+                 (maybeSimdFormatter = simdFormatters.get(constructor))) {
+        braces = ['[', ']'];
+        formatter = maybeSimdFormatter;
       } else {
         // Unset the constructor to prevent "Object {...}" for ordinary objects.
         if (constructor && constructor.name === 'Object')

test/parallel/test-util-format.js

@@ -7,7 +7,9 @@ const symbol = Symbol('foo');
 assert.equal(util.format(), '');
 assert.equal(util.format(''), '');
 assert.equal(util.format([]), '[]');
+assert.equal(util.format([0]), '[ 0 ]');
 assert.equal(util.format({}), '{}');
+assert.equal(util.format({foo: 42}), '{ foo: 42 }');
 assert.equal(util.format(null), 'null');
 assert.equal(util.format(true), 'true');
 assert.equal(util.format(false), 'false');

test/parallel/test-util-inspect-simd.js

@@ -59,3 +59,12 @@ if (typeof SIMD.Uint8x16 === 'function') {
       inspect(SIMD.Uint8x16()),
       'Uint8x16 [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ]');
 }
+
+// Tests from test-inspect.js that should not fail with --harmony_simd.
+assert.strictEqual(inspect([]), '[]');
+assert.strictEqual(inspect([0]), '[ 0 ]');
+assert.strictEqual(inspect({}), '{}');
+assert.strictEqual(inspect({foo: 42}), '{ foo: 42 }');
+assert.strictEqual(inspect(null), 'null');
+assert.strictEqual(inspect(true), 'true');
+assert.strictEqual(inspect(false), 'false');