⚠ Experimental ⚠

This feature may get big changes in future releases. Check the changelog for update notes.

Backtrace Annotations

Wrapping Errors

context objects have a backtrace which shows its GraphQL context. You can print the backtrace during query execution:

puts context.backtrace
# Loc  | Field                         | Object       | Arguments             | Result
# 3:13 | User.login                    | #<User id=1> | {"message"=>"Boom"}   | #<RuntimeError: This is broken: Boom>
# 2:11 | Query.user                    | nil          | {"login"=>"rmosolgo"} | {}
# 1:9  | query                         | nil          | {"msg"=>"Boom"}       |

The backtrace contains some execution data:

Loc is the line:column of the field in the query string
Field is the TypeName.fieldName of the fields in the backtrace
Object is the obj for query resolution (used for resolving the given field), equivalent to obj.inspect
Arguments are the GraphQL arguments for field resolution (including any default values and variable values)
Result is the GraphQL-ready result which is being constructed (it may be incomplete if the query is still in-progress)

Wrapping Errors

You can wrap unhandled errors with a GraphQL error with GraphQL::Backtrace.

To enable this feature for a query, add backtrace: true to your context, for example:

# Wrap this query with backtrace annotation
MySchema.execute(query_string, context: { backtrace: true })

Or, to always wrap backtraces, add it to your schema definition with use, for example:

class MySchema < GraphQL::Schema
  # Always wrap backtraces with GraphQL annotation
  use GraphQL::Backtrace
end

Now, any unhandled errors will be wrapped by GraphQL::Backtrace::TracedError, which prints out the GraphQL backtrace, too. For example:

Unhandled error during GraphQL execution:

  This is broken: Boom
    /Users/rmosolgo/code/graphql-ruby/spec/graphql/backtrace_spec.rb:27:in `block (3 levels) in <top (required)>'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/schema/build_from_definition/resolve_map.rb:57:in `call'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/schema/build_from_definition.rb:171:in `block in build_object_type'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/schema/build_from_definition.rb:280:in `block (2 levels) in build_fields'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/field.rb:228:in `resolve'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/execution/execute.rb:253:in `call'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/schema/middleware_chain.rb:45:in `invoke_core'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/schema/middleware_chain.rb:38:in `invoke'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/execution/execute.rb:107:in `resolve_field'
    /Users/rmosolgo/code/graphql-ruby/lib/graphql/execution/execute.rb:71:in `block (2 levels) in resolve_selection'
    ... and 65 more lines

Use #cause to access the original exception (including #cause.backtrace).

GraphQL Backtrace:
Loc  | Field                         | Object     | Arguments           | Result
3:13 | Thing.raiseField as boomError | :something | {"message"=>"Boom"} | #<RuntimeError: This is broken: Boom>
2:11 | Query.field1                  | "Root"     | {}                  | {}
1:9  | query                         | "Root"     | {"msg"=>"Boom"}     | {}

Backtrace Annotations

Contents

Wrapping Errors