added unit testing, and started implementing unit tests...phew

node_modules/winston/test/transports/01-file-maxsize.test.js

@@ -0,0 +1,121 @@
+/*
+ * file-test.js: Tests for instances of the File transport
+ *
+ * (C) 2010 Charlie Robbins
+ * MIT LICENSE
+ *
+ */
+const rimraf = require('rimraf');
+const fs = require('fs');
+const path = require('path');
+const assume = require('assume');
+const winston = require('../../');
+
+const MESSAGE = Symbol.for('message');
+
+//
+// Remove all log fixtures
+//
+function removeFixtures(done) {
+  rimraf(path.join(__dirname, '..', 'fixtures', 'logs', 'testmaxsize*'), done);
+}
+
+describe('File (maxsize)', function () {
+  this.timeout(10000);
+
+  let testDone = false;
+  before(removeFixtures);
+  after(done => {
+    testDone = true;
+    removeFixtures(done);
+  });
+
+  it('should create multiple files correctly when passed more than the maxsize', function (done) {
+    const fillWith = ['a', 'b', 'c', 'd', 'e'];
+    const maxsizeTransport = new winston.transports.File({
+      level: 'info',
+      format: winston.format.printf(info => info.message),
+      filename: path.join(__dirname, '..', 'fixtures', 'logs', 'testmaxsize.log'),
+      maxsize: 4096
+    })
+
+    //
+    // Have to wait for `fs.stats` to be done in `maxsizeTransport.open()`.
+    // Otherwise the maxsizeTransport._dest is undefined. See https://github.com/winstonjs/winston/issues/1174
+    //
+    setTimeout(() => logKbytes(4), 100);
+
+    //
+    // Setup a list of files which we will later stat.
+    //
+    const files = [];
+
+    //
+    // Assets all the files have been created with the
+    // correct filesize
+    //
+    function assumeFilesCreated() {
+      files.map(function (file, i) {
+        let stats;
+        try {
+          stats = fs.statSync(file);
+        } catch (ex) {
+          assume(stats).is.an('object', `${file} failed to open: ${ex.message}`);
+        }
+
+        const text = fs.readFileSync(file, 'utf8');
+        assume(text[0]).equals(fillWith[i]);
+        // Either 4096 on Unix or 4100 on Windows
+        // because of the eol.
+        if (process.platform === 'win32') {
+          assume(stats.size).equals(4100);
+        } else {
+          assume(stats.size).equals(4096);
+        }
+      });
+
+      done();
+    }
+
+    //
+    // Log the specified kbytes to the transport
+    //
+    function logKbytes(kbytes) {
+      //
+      // Shift the next fill char off the array then push it back
+      // to rotate the chars.
+      //
+      const filler = fillWith.shift();
+      fillWith.push(filler);
+
+      //
+      //
+      // To not make each file not fail the assertion of the filesize we can
+      // make the array 1023 characters long.
+      //
+      const kbStr = Array(1023).fill(filler).join('');
+
+      //
+      // With printf format that displays the message only
+      // winston adds exactly 0 characters.
+      //
+      for (var i = 0; i < kbytes; i++) {
+        maxsizeTransport.log({ level: 'info', [MESSAGE]: kbStr });
+      }
+    }
+
+    maxsizeTransport.on('open', function (file) {
+      if (testDone) return; // ignore future notifications
+
+      const match = file.match(/(\d+)\.log$/);
+      const count = match ? match[1] : 0;
+
+      if (files.length === 5) {
+        return assumeFilesCreated();
+      }
+
+      files.push(file);
+      setImmediate(() => logKbytes(4));
+    });
+  });
+});