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Added support for constructing from ArrayBuffer and added test that verifies support #42

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Added support for constructing from ArrayBuffer and added test that verifies support #42

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6 changes: 5 additions & 1 deletion index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,11 @@ function Buffer (subject, encoding, noZero) {
} else if (type === 'object' && subject !== null) { // assume object is array-like
if (subject.type === 'Buffer' && isArray(subject.data))
subject = subject.data
length = +subject.length > 0 ? Math.floor(+subject.length) : 0
// Support ArrayBuffer subjects
if (subject.length === undefined && typeof subject.byteLength === 'number')
length = subject.byteLength
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It's actually not enough to just set the length correctly. subject itself should be wrapped in a Uint8Array so the data can actually be pulled out.

else
length = +subject.length > 0 ? Math.floor(+subject.length) : 0
} else
throw new Error('First argument needs to be a number, array or string.')

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13 changes: 13 additions & 0 deletions test/basic.js
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Expand Up @@ -138,6 +138,19 @@ test('new buffer from float64array', function (t) {
t.end()
})

test('new buffer from ArrayBuffer', function(t) {
if (typeof ArrayBuffer !== 'undefined' && typeof DataView !== 'undefined') {
var b1 = new ArrayBuffer(2)
var dataView = new DataView(b1)
dataView.setInt16(0, 256, true)
var b2 = new B(b1)
t.equal(b1.byteLength, b2.length)
t.equal(b1[0], 0)
t.equal(b1[1], 1)
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Indexing into ArrayBuffers doesn't work. It's a bug that it works in node 0.10 and will fail in node 0.12 and browsers

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Interesting, yeah I only tested this in latest Chrome (works like a charm, can parse and send MQTT over WebSocket) and assumed from the lack of any other accessors this would be the only way to have it work.

I can try to change the websocket-stream library to construct an Uint8Array from the ArrayBuffer before wrapping with a Buffer.

}
t.end()
})

test('buffer toArrayBuffer()', function (t) {
var data = [1, 2, 3, 4, 5, 6, 7, 8]
if (typeof Uint8Array !== 'undefined') {
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