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Diffstat (limited to 'testing/web-platform/tests/serial/resources/common.js')
-rw-r--r-- | testing/web-platform/tests/serial/resources/common.js | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/testing/web-platform/tests/serial/resources/common.js b/testing/web-platform/tests/serial/resources/common.js new file mode 100644 index 0000000000..5177f83a86 --- /dev/null +++ b/testing/web-platform/tests/serial/resources/common.js @@ -0,0 +1,33 @@ +// Compare two Uint8Arrays. +function compareArrays(actual, expected) { + assert_true(actual instanceof Uint8Array, 'actual is Uint8Array'); + assert_true(expected instanceof Uint8Array, 'expected is Uint8Array'); + assert_equals(actual.byteLength, expected.byteLength, 'lengths equal'); + for (let i = 0; i < expected.byteLength; ++i) + assert_equals(actual[i], expected[i], `Mismatch at position ${i}.`); +} + +// Reads from |reader| until at least |targetLength| is read or the stream is +// closed. The data is returned as a combined Uint8Array. +async function readWithLength(reader, targetLength) { + const chunks = []; + let actualLength = 0; + + while (true) { + let {value, done} = await reader.read(); + chunks.push(value); + actualLength += value.byteLength; + + if (actualLength >= targetLength || done) { + // It would be better to allocate |buffer| up front with the number of + // of bytes expected but this is the best that can be done without a + // BYOB reader to control the amount of data read. + const buffer = new Uint8Array(actualLength); + chunks.reduce((offset, chunk) => { + buffer.set(chunk, offset); + return offset + chunk.byteLength; + }, 0); + return buffer; + } + } +} |