Transformer : Object

Passed to the TransformStream constructor. Any JavaScript object can be used as a Transformer. Any of the properties can be specified. If a property is not provided, the TransformStream will use a default behavior for the property.

Spec

Instance Methods

flush(controller : TransformStreamDefaultController) : Promise<undefined>

Example:

// Create a stream of strings.
const stringStream = new ReadableStream({
  start(controller) {
    ['a', 'b', 'c'].forEach(s => controller.enqueue(s));
    controller.close();
  }
});

// Transform the stream into upper case.
const upperCaseStream = stringStream.pipeThrough(new TransformStream({
  transform(chunk, controller) {
    controller.enqueue(chunk.toUpperCase());
  }
}));

const reader = upperCaseStream.getReader();
let result;
while (!(result = await reader.read()).done) {
  console.log(result.value);
}

Run

Results:

Spec

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