(interactor) find context by finding error callsite with regex

lib/Interactor/Utility.js

@@ -92,43 +92,90 @@ function StackTraceParser (opts) {
   this._context_size = opts.context;
 }
 
+StackTraceParser.prototype.attachContext = function (error) {
+  var self = this;
+  if (!error) return error;
+
+  // if pmx attached callsites we can parse them to retrieve the context
+  if (typeof (error.stackframes) === 'object') {
+    var result = self.parse(error.stackframes);
+    // no need to send it since there is already the stacktrace
+    delete error.stackframes;
+    delete error.__error_callsites;
+
+    if (result) {
+      error.callsite = result.callsite;
+      error.context = result.context;
+    }
+  }
+  // if the stack is here we can parse it directly from the stack string
+  // only if the context has been retrieved from elsewhere
+  if (typeof error.stack === 'string' && !error.callsite) {
+    var siteRegex = /(\/[^\\\n]*)/g;
+    var tmp;
+    var stack = [];
+
+    // find matching groups
+    while ((tmp = siteRegex.exec(error.stack))) {
+      stack.push(tmp[1]);
+    }
+
+    // parse each callsite to match the format used by the stackParser
+    stack = stack.map(function (callsite) {
+      // remove the trailing ) if present
+      if (callsite[callsite.length - 1] === ')') {
+        callsite = callsite.substr(0, callsite.length - 1);
+      }
+      var location = callsite.split(':');
+
+      return location.length < 3 ? callsite : {
+        file_name: location[0],
+        line_number: parseInt(location[1])
+      };
+    });
+
+    var finalCallsite = self.parse(stack);
+    if (finalCallsite) {
+      error.callsite = finalCallsite.callsite;
+      error.context = finalCallsite.context;
+    }
+  }
+  return error;
+};
+
 /**
  * Parse the stacktrace and return callsite + context if available
  */
 StackTraceParser.prototype.parse = function (stack) {
   var self = this;
-  if (!stack || stack.length == 0)
-    return false;
+  if (!stack || stack.length === 0) return false;
 
   for (var i = 0, len = stack.length; i < len; i++) {
     var callsite = stack[i];
 
     // avoid null values
-    if (!callsite ||
-        !callsite.file_name ||
-        !callsite.line_number)
-      continue;
+    if (typeof callsite !== 'object') continue;
+    if (!callsite.file_name || !callsite.line_number) continue;
 
-    var type = (!path.isAbsolute(callsite.file_name) && callsite.file_name[0] !== '.') ? 'core' : 'user'
+    var type = path.isAbsolute(callsite.file_name) || callsite.file_name[0] === '.' ? 'user' : 'core';
 
     // only use the callsite if its inside user space
-    if (!callsite ||
-        type === 'core' ||
-        callsite.file_name.indexOf('node_modules') > -1 ||
-        callsite.file_name.indexOf('vxx') > -1)
+    if (!callsite || type === 'core' || callsite.file_name.indexOf('node_modules') > -1 ||
+        callsite.file_name.indexOf('vxx') > -1) {
       continue;
+    }
 
     // get the whole context (all lines) and cache them if necessary
-    var context = self._cache.get(callsite.file_name)
-    var source = []
+    var context = self._cache.get(callsite.file_name);
+    var source = [];
     if (context && context.length > 0) {
       // get line before the call
       var preLine = callsite.line_number - self._context_size - 1;
       var pre = context.slice(preLine > 0 ? preLine : 0, callsite.line_number - 1);
       if (pre && pre.length > 0) {
         pre.forEach(function (line) {
-          source.push(line.replace(/\t/g, '  '))
-        })
+          source.push(line.replace(/\t/g, '  '));
+        });
       }
       // get the line where the call has been made
       if (context[callsite.line_number - 1]) {
@@ -136,23 +183,23 @@ StackTraceParser.prototype.parse = function (stack) {
       }
       // and get the line after the call
       var postLine = callsite.line_number + self._context_size;
-      var post = context.slice(callsite.line_number, postLine)
+      var post = context.slice(callsite.line_number, postLine);
       if (post && post.length > 0) {
         post.forEach(function (line) {
-          source.push(line.replace(/\t/g, '  '))
-        })
-      }
-      return {
-        context: source.join('\n'),
-        callsite: [ callsite.file_name, callsite.line_number ].join(':')
+          source.push(line.replace(/\t/g, '  '));
+        });
       }
     }
+    return {
+      context: source.length > 0 ? source.join('\n') : 'cannot retrieve source context',
+      callsite: [ callsite.file_name, callsite.line_number ].join(':')
+    };
   }
   return false;
-}
+};
 
 module.exports = {
   EWMA: EWMA,
   Cache: Cache,
   StackTraceParser: StackTraceParser
-}
+};

test/interface/stacktrace.mocha.js

@@ -5,6 +5,7 @@ var Utility = require('../../lib/Interactor/Utility.js');
 var TraceFactory = require('./misc/trace_factory.js');
 var path = require('path');
 var fs = require('fs');
+var assert = require('assert');
 
 describe('StackTrace Utility', function() {
   var aggregator;
@@ -29,7 +30,7 @@ describe('StackTrace Utility', function() {
     aggregator = new Aggregator({ stackParser: stackParser});
   });
 
-  describe('.parseStacktrace', function() {
+  describe('.parse', function() {
     it('should parse stacktrace and get context', function(done) {
       var obj = [{
         labels: {
@@ -125,4 +126,32 @@ describe('StackTrace Utility', function() {
     });
 
   });
+
+  describe('.attachContext', function () {
+    it('should extract context from stackframes', function () {
+      var error = stackParser.attachContext({
+        stackframes: [
+          {
+            file_name: '/toto/tmp/lol',
+            line_number: 10
+          }
+        ]
+      });
+      assert(error !== undefined);
+      assert(error.stackframes === undefined);
+      assert(error.callsite !== undefined);
+      assert(error.callsite.indexOf('/toto/tmp/lol') >= 0);
+    });
+
+    it('should extract context from the stack string', function () {
+      var error = new Error();
+      // stack is lazy so we need to load it
+      error.stack = error.stack;
+      error = stackParser.attachContext(error);
+      assert(error !== undefined);
+      assert(error.stackframes === undefined);
+      assert(error.callsite.indexOf(__filename) >= 0);
+      assert(error.context.indexOf('var error = new Error()') >= 0);
+    });
+  });
 });