Safely pipe node.js streams while capturing all errors to a single promise
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Latest commit 226d7dd Sep 16, 2015 @epeli Merge pull request #1 from marekventur/patch-1
Fix typo in Readme


Safely pipe node.js streams while capturing all errors to a single promise.


promisePipe(<readable stream>, [transform streams...], <writeable stream>)

It returns a promise. On success the resolved value will be an array of the streams passed in. When rejected an error object is created with following keys:

  • source: The stream that caused the error
  • originalError: Original error from the stream
  • message: The error message from original error


var promisePipe = require("promisepipe");

    new UpcaseTransform(),
    console.log("Yay, all streams are now closed/ended/finished!");
}, function(err) {
    console.log("This stream failed:", err.source);
    console.log("Original error was:", err.originalError);


npm instal promisepipe


Stream piping in node.js is cool, but error handling is not because streams do not bubble errors to the target streams.

For example if the previous example is written like this:

.pipe(new UpcaseTransform())

It might crash your program at any time. You must handle the errors from each stream manually like this:

fs.createReadStream(INPUT_FILE).on("error", function(err) {
    // handle the error
}).pipe(new UpcaseTransform()).on("error", function(err) {
    // handle the error
}).pipe(fs.createReadStream(OUTPUT_FILE)).on("error", function(err) {
    // handle the error

Which is imo repeative and cumbersome (at least when you want to use promises).