Version 1

[yaffs-website] / node_modules / phridge / lib / forkStdout.js

diff --git a/node_modules/phridge/lib/forkStdout.js b/node_modules/phridge/lib/forkStdout.js
new file mode 100644 (file)
index 0000000..68fc098
--- /dev/null
+++ b/node_modules/phridge/lib/forkStdout.js
@@ -0,0 +1,89 @@
+"use strict";
+
+var os = require("os");
+var util = require("util");
+var ForkStream = require("fork-stream");
+var Linerstream = require("linerstream");
+var Transform = require("stream").Transform;
+
+var messageToNode = "message to node: ";
+
+/**
+ * Creates a fork stream which pipes messages starting with 'message to node: ' to our phridge stream
+ * and any other message to the other stream. Thus console.log() inside PhantomJS is still printed to the
+ * console while using stdout as communication channel for phridge.
+ *
+ * @param {stream.Readable} stdout
+ * @returns {{phridge: stream.Readable, cleanStdout: stream.Readable}}
+ */
+function forkStdout(stdout) {
+    var fork;
+    var phridgeEndpoint;
+    var cleanStdoutEndpoint;
+
+    // Expecting a character stream because we're splitting messages by an EOL-character
+    stdout.setEncoding("utf8");
+
+    fork = new ForkStream({
+        classifier: function (chunk, done) {
+            chunk = chunk
+                .slice(0, messageToNode.length);
+            done(null, chunk === messageToNode);
+        }
+    });
+
+    stdout
+        .pipe(new Linerstream())
+        .pipe(fork);
+
+    // Removes the 'message to node: '-prefix from every chunk.
+    phridgeEndpoint = fork.a.pipe(new CropPhridgePrefix({
+        encoding: "utf8"
+    }));
+
+    // We need to restore EOL-character in stdout stream
+    cleanStdoutEndpoint = fork.b.pipe(new RestoreLineBreaks({
+        encoding: "utf8"
+    }));
+
+    return {
+        phridge: phridgeEndpoint,
+        cleanStdout: cleanStdoutEndpoint
+    };
+}
+
+/**
+ * Appends an EOL-character to every chunk.
+ *
+ * @param {Object} options stream options
+ * @constructor
+ * @private
+ */
+function RestoreLineBreaks(options) {
+    Transform.call(this, options);
+}
+util.inherits(RestoreLineBreaks, Transform);
+
+RestoreLineBreaks.prototype._transform = function (chunk, enc, cb) {
+    this.push(chunk + os.EOL);
+    cb();
+};
+
+/**
+ * Removes the 'message to node: '-prefix from every chunk.
+ *
+ * @param {Object} options stream options
+ * @constructor
+ * @private
+ */
+function CropPhridgePrefix(options) {
+    Transform.call(this, options);
+}
+util.inherits(CropPhridgePrefix, Transform);
+
+CropPhridgePrefix.prototype._transform = function (chunk, enc, cb) {
+    this.push(chunk.slice(messageToNode.length));
+    cb();
+};
+
+module.exports = forkStdout;