Enable maxExpandFrames config option

Matt Loring · Matt Loring · commit 14ac9e4abc8f · 2016-01-21T16:26:47.000-08:00
diff --git a/config.js b/config.js
@@ -46,8 +46,7 @@ module.exports = {
 
     // Only collect locals and arguments on a few top frames. For the rest
     // only collect the source location
-    // TODO: implement this
-    //maxExpandFrames: 5,
+    maxExpandFrames: 5,
 
     // To reduce the overall capture time, limit the number of properties
     // gathered on large object. A value of 0 disables the limit.
diff --git a/lib/state.js b/lib/state.js
@@ -23,12 +23,30 @@ module.exports = {
 
 var assert = require('assert');
 var semver = require('semver');
+var util = require('util');
 
 var StatusMessage = require('./apiclasses.js').StatusMessage;
 
 var BUFFER_FULL_MESSAGE_INDEX = 0;
 var NATIVE_PROPERTY_MESSAGE_INDEX = 1;
 var GETTER_MESSAGE_INDEX = 2;
+var ARG_LOCAL_LIMIT_MESSAGE_INDEX = 3;
+
+var MESSAGE_TABLE = [];
+MESSAGE_TABLE[BUFFER_FULL_MESSAGE_INDEX] =
+  { status: new StatusMessage(StatusMessage.VARIABLE_VALUE,
+                              'Max data size reached', true) };
+MESSAGE_TABLE[NATIVE_PROPERTY_MESSAGE_INDEX] =
+  { status: new StatusMessage(StatusMessage.VARIABLE_VALUE,
+                              'Native properties are not available', true) };
+MESSAGE_TABLE[GETTER_MESSAGE_INDEX] =
+  { status: new StatusMessage(StatusMessage.VARIABLE_VALUE,
+                              'Properties with getters are not available', true) };
+MESSAGE_TABLE[ARG_LOCAL_LIMIT_MESSAGE_INDEX] =
+  { status: new StatusMessage(StatusMessage.VARIABLE_VALUE,
+                              'Locals and arguments are only displayed for the ' +
+                              'top `config.capture.maxExpandFrames` stack frames.',
+                                true) };
 
 // TODO: document this file
 
@@ -83,17 +101,8 @@ function StateResolver(execState, expressions, config) {
   this.evaluatedExpressions_ = [];
   this.totalSize_ = 0;
 
-  this.rawVariableTable_ = [ null, null, null ];
-  this.resolvedVariableTable_ = [];
-  this.resolvedVariableTable_[BUFFER_FULL_MESSAGE_INDEX] =
-    { status: new StatusMessage(StatusMessage.VARIABLE_VALUE,
-                                'Max data size reached', true) };
-  this.resolvedVariableTable_[NATIVE_PROPERTY_MESSAGE_INDEX] =
-    { status: new StatusMessage(StatusMessage.VARIABLE_VALUE,
-                                'Native properties are not available', true) };
-  this.resolvedVariableTable_[GETTER_MESSAGE_INDEX] =
-    { status: new StatusMessage(StatusMessage.VARIABLE_VALUE,
-                                'Properties with getters are not available', true) };
+  this.resolvedVariableTable_ = util._extend([], MESSAGE_TABLE);
+  this.rawVariableTable_ = MESSAGE_TABLE.map(function() { return null; });
 }
 
 
@@ -122,7 +131,7 @@ StateResolver.prototype.capture = function() {
   }
 
   // Now resolve the variables
-  var index = 3; // skip the sentinel values
+  var index = MESSAGE_TABLE.length; // skip the sentinel values
   while (index < that.rawVariableTable_.length && // NOTE: length changes in loop
          that.totalSize_ < that.config_.capture.maxDataSize) {
     assert(!that.resolvedVariableTable_[index]); // shouldn't have it resolved yet
@@ -177,7 +186,8 @@ StateResolver.prototype.resolveFrames_ = function() {
   for (var i = 0; i < this.state_.frameCount(); i++) {
     var frame = this.state_.frame(i);
     if (this.shouldFrameBeResolved_(frame)) {
-      frames.push(this.resolveFrame_(frame));
+      var resolveVars = i < this.config_.capture.maxExpandFrames;
+      frames.push(this.resolveFrame_(frame, resolveVars));
     }
   }
   return frames;
@@ -242,13 +252,20 @@ StateResolver.prototype.isPathInNodeModulesDirectory_ = function(path) {
 };
 
 
-StateResolver.prototype.resolveFrame_ = function(frame) {
-  var args = this.resolveArgumentList_(frame);
+StateResolver.prototype.resolveFrame_ = function(frame, resolveVars) {
+  var args = resolveVars ? this.resolveArgumentList_(frame) : [{
+    name: 'arguments_not_available',
+    varTableIndex: ARG_LOCAL_LIMIT_MESSAGE_INDEX
+  }];
+  var locals = resolveVars ? this.resolveLocalsList_(frame, args) : [{
+    name: 'locals_not_available',
+    varTableIndex: ARG_LOCAL_LIMIT_MESSAGE_INDEX
+  }];
   return {
     function: this.resolveFunctionName_(frame.func()),
     location: this.resolveLocation_(frame),
     arguments: args,
-    locals: this.resolveLocalsList_(frame, args)
+    locals: locals
   };
 };
 
diff --git a/test/test-v8debugapi.js b/test/test-v8debugapi.js
@@ -307,6 +307,35 @@ describe('v8debugapi', function() {
       });
     });
 
+    it('should resolve correct frame count', function(done) {
+      // clone a clean breakpointInFoo
+      var bp  = {id: breakpointInFoo.id, location: breakpointInFoo.location};
+      var oldCount = config.capture.maxExpandFrames;
+      config.capture.maxExpandFrames = 0;
+      api.set(bp, function(err) {
+        assert.ifError(err);
+        api.wait(bp, function(err) {
+          assert.ifError(err);
+          assert.ok(bp.stackFrames);
+          assert.ok(bp.variableTable);
+
+          var topFrame = bp.stackFrames[0];
+          assert.ok(topFrame);
+          assert.equal(topFrame['function'], 'foo');
+          assert.equal(topFrame.arguments.length, 1);
+          var argsVal = bp.variableTable[topFrame.arguments[0].varTableIndex];
+          assert(argsVal.status.isError);
+          assert.equal(topFrame.locals.length, 1);
+          var localsVal = bp.variableTable[topFrame.locals[0].varTableIndex];
+          assert(localsVal.status.isError);
+          api.clear(bp);
+          config.capture.maxExpandFrames = oldCount;
+          done();
+        });
+      process.nextTick(function() {foo(2);});
+      });
+    });
+
     it('should capture state with watch expressions', function(done) {
       // clone a clean breakpointInFoo
       var bp  = {
