[project] added

haxetool/tail.js

@@ -0,0 +1,43 @@
+const through = require('through2');
+const colors = require('ansi-colors');
+const log = require('fancy-log');
+
+const TAG = colors.green('[tail]');
+
+
+const { Writable } = require('stream');
+const { StringDecoder } = require('string_decoder');
+
+
+class StringWritable extends Writable {
+    constructor(handler, options) {
+        super(options);
+        this.handler = handler;
+        const state = this._writableState;
+        this._decoder = new StringDecoder(state.defaultEncoding);
+        this.data = '';
+    }
+    _write(chunk, encoding, callback) {
+        if (encoding === 'buffer') {
+            chunk = this._decoder.write(chunk);
+            for (const line of chunk.split('\n')) if (line.length) {
+                this.handler(line);
+            }
+        }
+        this.data += chunk;
+        callback();
+    }
+    _final(callback) {
+        this.data += this._decoder.end();
+        callback();
+    }
+}
+
+
+module.exports = (handler) => {
+    return through.obj(function (file, enc, callback) {
+        file.contents.pipe(new StringWritable(handler));
+        this.push(file);
+        callback();
+    });
+};