Feat: Custom logger

README.md

@@ -82,6 +82,7 @@ app.use(fileUpload({
 
 You can set `debug` option to `true` to see some logging about upload process.
 In this case middleware uses `console.log` and adds `Express-file-upload` prefix for outputs.
+You can set a custom logger having `.log()` method to the `logger` option.
 
 It will show you whether the request is invalid and also common events triggered during upload.
 That can be really useful for troubleshooting and ***we recommend attaching debug output to each issue on Github***.
@@ -121,6 +122,7 @@ useTempFiles | <ul><li><code>false</code>&nbsp;**(default)**</li><li><code>true<
 tempFileDir | <ul><li><code>String</code>&nbsp;**(path)**</li></ul> | Path to store temporary files.<br />Used along with the <code>useTempFiles</code> option. By default this module uses 'tmp' folder in the current working directory.<br />You can use trailing slash, but it is not necessary.
 parseNested | <ul><li><code>false</code>&nbsp;**(default)**</li><li><code>true</code></li></ul> | By default, req.body and req.files are flattened like this: <code>{'name': 'John', 'hobbies[0]': 'Cinema', 'hobbies[1]': 'Bike'}</code><br /><br/>When this option is enabled they are parsed in order to be nested like this: <code>{'name': 'John', 'hobbies': ['Cinema', 'Bike']}</code>
 debug | <ul><li><code>false</code>&nbsp;**(default)**</li><li><code>true</code></ul> | Turn on/off upload process logging. Can be useful for troubleshooting.
+logger | <ul><li><code>console</code>&nbsp;**(default)**</li><li><code>{log: function(msg: string)}</code></li></ul> | Customizable logger to write debug messages to. Console is default.
 uploadTimeout | <ul><li><code>60000</code>&nbsp;**(default)**</li><li><code>Integer</code></ul> | This defines how long to wait for data before aborting. Set to 0 if you want to turn off timeout checks.
 
 # Help Wanted

lib/index.js

@@ -8,6 +8,7 @@ const busboy = require('busboy'); // eslint-disable-line no-unused-vars
 
 const DEFAULT_OPTIONS = {
   debug: false,
+  logger: console,
   uploadTimeout: 60000,
   fileHandler: false,
   uriDecodeFileNames: false,

lib/utilities.js

@@ -21,8 +21,8 @@ let tempCounter = 0;
  */
 const debugLog = (options, msg) => {
   const opts = options || {};
-  if (!opts.debug) return false;
-  console.log(`Express-file-upload: ${msg}`); // eslint-disable-line
+  if (!opts.debug || !opts.logger || typeof opts.logger.log !== "function") return false;
+  opts.logger.log(`Express-file-upload: ${msg}`);
   return true;
 };
 

test/utilities.spec.js

@@ -42,12 +42,24 @@ describe('utilities: Test of the utilities functions', function() {
       assert.equal(debugLog(null, testMessage), false);
     });
 
-    it('debugLog returns false if option debug is false', () => {
+    it('debugLog returns false if option debug is false or logger is not set', () => {
       assert.equal(debugLog({debug: false}, testMessage), false);
+      assert.equal(debugLog({debug: true, logger: undefined}, testMessage), false);
+      assert.equal(debugLog({debug: true, logger: {}}, testMessage), false);
     });
 
-    it('debugLog returns true if option debug is true', () => {
-      assert.equal(debugLog({debug: true}, testMessage), true);
+    it('debugLog returns true if option debug is true and logger is set', () => {
+      assert.equal(debugLog({debug: true, logger: console}, testMessage), true);
+    });
+
+    it('supports a custom logger', () => {
+      const calls = [];
+      const logger = {
+        log: (...args) => calls.push(args)
+      };
+      debugLog({debug: true, logger}, testMessage);
+      assert.equal(calls.length, 1);
+      assert.deepEqual(calls[0], [`Express-file-upload: ${testMessage}`]);
     });
 
   });