Loggity

Simplified log test, and added in the ability to pass in custom log method.

I thought this was outside of the scope of my pr but just kinda did it because the test output bugged me lol.

Author: freddyCfit

src/neural-network.js

@@ -246,6 +246,21 @@ export default class NeuralNetwork {
     return sizes;
   }
 
+
+  /**
+   *
+   * @param log
+   * if true passed in console.log is used
+   * if a method is passed in method is used
+   * if false passed in nothing is logged
+   * @returns error
+   */
+  _setLogMethod (log) {
+    if (typeof log === 'function') return log;
+    if (log) return console.log;
+    return false;
+  }
+
   /**
    *
    * @param data
@@ -270,7 +285,7 @@ export default class NeuralNetwork {
     status.error = this._calculateTrainingError(data, options.learningRate);
 
     if (options.log && (status.iterations % options.logPeriod === 0)) {
-      console.log (`iterations: ${status.iterations}, training error: ${status.error}`);
+      options.log (`iterations: ${status.iterations}, training error: ${status.error}`);
     }
 
     if (options.callback && (status.iterations % options.callbackPeriod === 0)) {
@@ -287,6 +302,7 @@ export default class NeuralNetwork {
   train (data, _options = {}) {
     let options = Object.assign({}, this.constructor.trainDefaults, _options);
     data = this.formatData(data);
+    options.log = this._setLogMethod(options.log);
     options.learningRate = _options.learningRate || this.learningRate || options.learningRate;
     let endTime = Date.now() + options.trainTimeMs;
     var status = {
@@ -315,6 +331,7 @@ export default class NeuralNetwork {
     return new Promise ((resolve, reject) => {
       let options = Object.assign({}, this.constructor.trainDefaults, _options);
       data = this.formatData(data);
+      options.log = this._setLogMethod(options.log);
       options.learningRate = _options.learningRate || this.learningRate || options.learningRate;
       let endTime = Date.now() + options.trainTimeMs;
 

test/base/options.js

@@ -131,20 +131,12 @@ describe ('async neural network options', () => {
 
 
 describe('log', () => {
-  let logCalled;
-  let oldLog;
+  let logCalled = false;
 
   beforeEach (() => { logCalled = false; });
 
-  before (() => { oldLog = console.log; console.log = logFunction; });
-  after (() => { console.log = oldLog; });
-
   function logFunction(str) {
-    if (typeof str === "string" && !str.includes('iterations:') && !str.includes('training error:')) {
-      oldLog(str);
-    } else {
-      logCalled = true;
-    }
+    logCalled = true;
   }
 
   function trainWithLog (log, expected) {
@@ -159,7 +151,10 @@ describe('log', () => {
   function trainWithLogAsync (log, expected, done) {
     let net = new brain.NeuralNetwork();
     net
-      .trainAsync ([ {input: [0], output: [0]} ], { log: log, logPeriod: 1, iterations: 1 })
+      .trainAsync (
+        [ {input: [0], output: [0]} ],
+        { log: log, logPeriod: 1, iterations: 1 }
+      )
       .then (res => {
         assert.equal (logCalled, expected);
         done ();
@@ -169,10 +164,9 @@ describe('log', () => {
       });
   }
 
-  // TODO fix this test :(
-  it('should call console.log if log === true', () => { trainWithLog (true, true); });
-  it('should call console.log if log === false', () => { trainWithLog (false, false); });
+  it('should call log method', () => { trainWithLog (logFunction, true); });
+  it('should not call log method', () => { trainWithLog (false, false); });
 
-  it('ASYNC should call console.log if log === true', done => { trainWithLogAsync (true, true, done); }).timeout(5000);
-  it('ASYNC should call console.log if log === false', done => { trainWithLogAsync (false, false, done); }).timeout(5000);
+  it('ASYNC should call log method', done => { trainWithLogAsync (logFunction, true, done); }).timeout(5000);
+  it('ASYNC should not call log method', done => { trainWithLogAsync (false, false, done); }).timeout(5000);
 });