util: make inspect more reliable

34a35919e165cba6d5972e004e6b2cbdf2f4c65a added pretty printing for
TypedArray, ArrayBuffer, and DataView. This change allows inspecting
those across different contexts.

Since instanceof does not work across contexts, we can use
v8::Value::IsTypedArray, v8::Value::IsArrayBuffer, and
v8::Value::IsDataView

PR-URL: https://github.com/nodejs/node/pull/4098
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 62 insertions, 0 deletions

diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index 93ac7157fd..3a033eb3aa 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -2,6 +2,7 @@
 var common = require('../common');
 var assert = require('assert');
 var util = require('util');
+const vm = require('vm');
 
 assert.equal(util.inspect(1), '1');
 assert.equal(util.inspect(false), 'false');
@@ -68,6 +69,35 @@ for (const showHidden of [true, false]) {
                '  y: 1337 }');
 }
 
+// Now do the same checks but from a different context
+for (const showHidden of [true, false]) {
+  const ab = vm.runInNewContext('new ArrayBuffer(4)');
+  const dv = vm.runInNewContext('new DataView(ab, 1, 2)', { ab: ab });
+  assert.equal(util.inspect(ab, showHidden), 'ArrayBuffer { byteLength: 4 }');
+  assert.equal(util.inspect(new DataView(ab, 1, 2), showHidden),
+               'DataView {\n' +
+               '  byteLength: 2,\n' +
+               '  byteOffset: 1,\n' +
+               '  buffer: ArrayBuffer { byteLength: 4 } }');
+  assert.equal(util.inspect(ab, showHidden), 'ArrayBuffer { byteLength: 4 }');
+  assert.equal(util.inspect(dv, showHidden),
+               'DataView {\n' +
+               '  byteLength: 2,\n' +
+               '  byteOffset: 1,\n' +
+               '  buffer: ArrayBuffer { byteLength: 4 } }');
+  ab.x = 42;
+  dv.y = 1337;
+  assert.equal(util.inspect(ab, showHidden),
+               'ArrayBuffer { byteLength: 4, x: 42 }');
+  assert.equal(util.inspect(dv, showHidden),
+               'DataView {\n' +
+               '  byteLength: 2,\n' +
+               '  byteOffset: 1,\n' +
+               '  buffer: ArrayBuffer { byteLength: 4, x: 42 },\n' +
+               '  y: 1337 }');
+}
+
+
 [ Float32Array,
   Float64Array,
   Int16Array,
@@ -94,6 +124,38 @@ for (const showHidden of [true, false]) {
     assert.equal(util.inspect(array, false), `${constructor.name} [ 65, 97 ]`);
   });
 
+// Now check that declaring a TypedArray in a different context works the same
+[ Float32Array,
+  Float64Array,
+  Int16Array,
+  Int32Array,
+  Int8Array,
+  Uint16Array,
+  Uint32Array,
+  Uint8Array,
+  Uint8ClampedArray ].forEach(constructor => {
+    const length = 2;
+    const byteLength = length * constructor.BYTES_PER_ELEMENT;
+    const array = vm.runInNewContext('new constructor(new ArrayBuffer(' +
+                                     'byteLength), 0, length)',
+                                     { constructor: constructor,
+                                       byteLength: byteLength,
+                                       length: length
+                                     });
+    array[0] = 65;
+    array[1] = 97;
+    assert.equal(util.inspect(array, true),
+                 `${constructor.name} [\n` +
+                 `  65,\n` +
+                 `  97,\n` +
+                 `  [BYTES_PER_ELEMENT]: ${constructor.BYTES_PER_ELEMENT},\n` +
+                 `  [length]: ${length},\n` +
+                 `  [byteLength]: ${byteLength},\n` +
+                 `  [byteOffset]: 0,\n` +
+                 `  [buffer]: ArrayBuffer { byteLength: ${byteLength} } ]`);
+    assert.equal(util.inspect(array, false), `${constructor.name} [ 65, 97 ]`);
+  });
+
 // Due to the hash seed randomization it's not deterministic the order that
 // the following ways this hash is displayed.
 // See http://codereview.chromium.org/9124004/