Merge pull request plotly#3137 from plotly/robust-log

prevent our loggers from throwing their own errors in a few more cases

Author: alexcjohnson

src/lib/loggers.js

@@ -61,12 +61,24 @@ loggers.error = function() {
  * apply like other functions do
  */
 function apply(f, args) {
-    if(f.apply) {
-        f.apply(f, args);
+    if(f && f.apply) {
+        try {
+            // `this` should always be console, since here we're always
+            // applying a method of the console object.
+            f.apply(console, args);
+            return;
+        }
+        catch(e) { /* in case apply failed, fall back on the code below */ }
     }
-    else {
-        for(var i = 0; i < args.length; i++) {
+
+    // no apply - just try calling the function on each arg independently
+    for(var i = 0; i < args.length; i++) {
+        try {
             f(args[i]);
         }
+        catch(e) {
+            // still fails - last resort simple console.log
+            console.log(args[i]);
+        }
     }
 }

test/jasmine/tests/lib_test.js

@@ -1654,6 +1654,7 @@ describe('Test lib.js:', function() {
 
         function consoleFn(name, hasApply, messages) {
             var out = function() {
+                if(hasApply) expect(this).toBe(window.console);
                 var args = [];
                 for(var i = 0; i < arguments.length; i++) args.push(arguments[i]);
                 messages.push([name, args]);
@@ -1664,12 +1665,13 @@ describe('Test lib.js:', function() {
             return out;
         }
 
-        function mockConsole(hasApply, hasTrace) {
+        function mockConsole(hasApply, hasTrace, hasError) {
             var out = {
                 MESSAGES: []
             };
             out.log = consoleFn('log', hasApply, out.MESSAGES);
-            out.error = consoleFn('error', hasApply, out.MESSAGES);
+
+            if(hasError) out.error = consoleFn('error', hasApply, out.MESSAGES);
 
             if(hasTrace) out.trace = consoleFn('trace', hasApply, out.MESSAGES);
 
@@ -1687,7 +1689,7 @@ describe('Test lib.js:', function() {
         });
 
         it('emits one console message if apply is available', function() {
-            var c = window.console = mockConsole(true, true);
+            var c = window.console = mockConsole(true, true, true);
             config.logging = 2;
 
             Lib.log('tick', 'tock', 'tick', 'tock', 1);
@@ -1702,7 +1704,7 @@ describe('Test lib.js:', function() {
         });
 
         it('falls back on console.log if no trace', function() {
-            var c = window.console = mockConsole(true, false);
+            var c = window.console = mockConsole(true, false, true);
             config.logging = 2;
 
             Lib.log('Hi');
@@ -1715,7 +1717,7 @@ describe('Test lib.js:', function() {
         });
 
         it('falls back on separate calls if no apply', function() {
-            var c = window.console = mockConsole(false, false);
+            var c = window.console = mockConsole(false, false, true);
             config.logging = 2;
 
             Lib.log('tick', 'tock', 'tick', 'tock', 1);
@@ -1744,7 +1746,7 @@ describe('Test lib.js:', function() {
         });
 
         it('omits .log at log level 1', function() {
-            var c = window.console = mockConsole(true, true);
+            var c = window.console = mockConsole(true, true, true);
             config.logging = 1;
 
             Lib.log(1);
@@ -1758,7 +1760,7 @@ describe('Test lib.js:', function() {
         });
 
         it('logs nothing at log level 0', function() {
-            var c = window.console = mockConsole(true, true);
+            var c = window.console = mockConsole(true, true, true);
             config.logging = 0;
 
             Lib.log(1);
@@ -1767,6 +1769,22 @@ describe('Test lib.js:', function() {
 
             expect(c.MESSAGES).toEqual([]);
         });
+
+        it('falls back on simple log if there is no console.error', function() {
+            // TODO
+
+            var c = window.console = mockConsole(true, true, false);
+            config.logging = 2;
+
+            Lib.error('who are you', 'who who... are you', {a: 1, b: 2});
+
+            expect(c.MESSAGES).toEqual([
+                ['log', ['ERROR:']],
+                ['log', ['who are you']],
+                ['log', ['who who... are you']],
+                ['log', [{a: 1, b: 2}]]
+            ]);
+        });
     });
 
     describe('keyedContainer', function() {