How do I only see the header of an error in Cucumber JS?

Question

How do I only see the header of an error in Cucumber JS?

I'm trying out some BDD with nodeJS using a grunt-triggered Cucumber JS task, which is working fine except that I don't want to see the full JS exception stack for a test that I know will of course fail. Instead, I'd rather just see the (more useful) head of the exception. It may seem trivial, but I'm lead to believe that BDD is best achieved with quick feedback from these sorts of tools. As an example, here's the full stack trace from a basic missing method from a module:

TypeError: Object #<Object> has no method 'delete'
    at World.<anonymous> ($HOME/features/step_definitions/delete-item.steps.js:20:21)
    at Object.invoke ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/step_definition.js:84:14)
    at Object.execute ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/step.js:157:22)
    at Object.acceptVisitor ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/step.js:149:12)
    at Object.executeStep ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:178:12)
    at Object.processStep ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:173:14)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:66:16
    at callUserFunctionAndBroadcastAfterEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:90:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at onRuntimeListenersComplete ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:113:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:20:11
    at hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:8:9)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:16:7
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:8:9)
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:15:18)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:118:51
    at processItem ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:19:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:12:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at Object.broadcastEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:109:7)
    at Object.broadcastBeforeEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:100:12)
    at Object.broadcastEventAroundUserFunction ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:84:12)
    at Object.visitStep ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:63:12)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/scenario.js:95:17
    at processItem ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:19:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:12:11)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:20:11
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at onRuntimeListenersComplete ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:113:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:20:11
    at hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:8:9)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:16:7
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:8:9)
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:15:18)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:118:51
    at processItem ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:19:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:12:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at Object.broadcastEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:109:7)
    at Object.broadcastAfterEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:105:12)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:95:32
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at onRuntimeListenersComplete ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:113:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:20:11
    at handleStepResult ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:27:5)
    at hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:6:9)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:16:7
    at handleStepResult ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/stats_journal.js:39:5)
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:6:9)
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:15:18)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:118:51
    at processItem ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:19:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:12:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at Object.broadcastEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:109:7)
    at Object.visitStepResult ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:79:12)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/step.js:150:17
    at codeCallback ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/step_definition.js:61:11)
    at World.<anonymous> ($HOME/features/step_definitions/delete-item.steps.js:16:3)
    at Object.invoke ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/step_definition.js:84:14)
    at Object.execute ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/step.js:157:22)
    at Object.acceptVisitor ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/step.js:149:12)
    at Object.executeStep ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:178:12)
    at Object.processStep ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:173:14)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:66:16
    at callUserFunctionAndBroadcastAfterEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:90:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at onRuntimeListenersComplete ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:113:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:20:11
    at hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:8:9)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:16:7
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:8:9)
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:15:18)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:118:51
    at processItem ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:19:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:12:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at Object.broadcastEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:109:7)
    at Object.broadcastBeforeEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:100:12)
    at Object.broadcastEventAroundUserFunction ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:84:12)
    at Object.visitStep ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:63:12)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/scenario.js:95:17
    at processItem ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:19:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:12:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at Object.instructVisitorToVisitSteps ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/scenario.js:94:13)
    at Object.instructVisitorToVisitScenarioSteps ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/scenario.js:90:12)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/scenario.js:75:14
    at Object.instructVisitorToVisitBackgroundSteps ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/scenario.js:85:9)
    at Object.acceptVisitor ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/scenario.js:74:12)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:48:41
    at callUserFunction ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/library/hooker.js:41:11)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at Object.triggerBeforeHooks ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/library/hooker.js:63:19)
    at callBeforeHooks ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/library/hooker.js:37:16)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at hookedUpFunction ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/library/hooker.js:27:21)
    at callUserFunctionAndBroadcastAfterEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:90:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at onRuntimeListenersComplete ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:113:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:14:11)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:20:11
    at hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:8:9)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:16:7
    at handleBeforeScenarioEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/stats_journal.js:24:5)
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener.js:6:9)
    at Object.hear ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/listener/summary_formatter.js:15:18)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:118:51
    at processItem ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:19:9)
    at iterate ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:12:11)
    at Object.forEach ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/type/collection.js:23:7)
    at broadcastToListeners ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:117:19)
    at Object.broadcastEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:109:7)
    at Object.broadcastBeforeEvent ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:100:12)
    at Object.broadcastEventAroundUserFunction ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:84:12)
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/runtime/ast_tree_walker.js:52:14
    at $HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/library.js:71:11
    at process._tickCallback (node.js:419:13)
    at Function.Module.runMain (module.js:499:11)
    at startup (node.js:119:16)
    at node.js:906:3

This is then followed by the more useful, but still not explicit:

Failing scenarios:
$HOME/features/delete-item.feature:6 # Scenario: Item removed from portfolio
$HOME/features/delete-item.feature:11 # Scenario: Item not accessible from portfolio

4 scenarios (2 failed, 2 passed)
12 steps (2 failed, 2 skipped, 8 passed)

Really, the only thing I care about in the majority of cases is the first four lines:

TypeError: Object #<Object> has no method 'delete'
at World.<anonymous> ($HOME/features/step_definitions/delete-item.steps.js:20:21)
at Object.invoke ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/support_code/step_definition.js:84:14)
at Object.execute ($HOME/node_modules/grunt-cucumber/node_modules/cucumber/lib/cucumber/ast/step.js:157:22)

Any ideas?

node.js
gruntjs
cucumberjs

Answer 1

You can absolutely limit the size of the collected stack traces in node.

In your code, set the following to log only the error message (the header) and none of the stack trace

Error.stackTraceLimit = 0;

Or, to see only the first four lines (error message plus 3 stack frames) use

Error.stackTraceLimit = 3;

This value gives node the maximum number of stack frames to collect, so you can set it to whatever's appropriate for your Error logging purposes in any given context.

Should you need to set it back to collect full stack traces at any point, you can use

Error.stackTraceLimit = Infinity;

UPDATE

You may also want to look at using hide-stack-frames-from

This solves the actual problem of de-nosing stack traces far more elegantly by filtering out unwanted frames from the stack trace, leaving only the pertinent ones, rather than the comparatively course alternative of truncating the stack and hoping those first n lines will point you to the root problem.

For example, you can replace the line above with

require('hide-stack-frames-from')('cucumber', 'bluebird', 'superagent');

Just pass the names of any modules whose stack frames you want to filter out.