This is a fairly major refactoring of coerceValue which returns an Either so it can return a complete collection of errors. This allows originalError to be preserved for scalar coercion errors and ensures *all* errors are represented in the response.
This had a minor change to the logic in execute / subscribe to allow for buildExecutionContext to abrupt complete with multiple errors.
ref: graphql/graphql-js#1133
Lifted from / inspired by a similar change in graphql/graphql-js#722, this creates a new function `printError()` (and uses it as the implementation for `GraphQLError#toString()`) which prints location information in the context of an error.
This is moved from the syntax error where it used to be hard-coded, so it may now be used to format validation errors, value coercion errors, or any other error which may be associated with a location.
ref: graphql/graphql-js
BREAKING CHANGE: The SyntaxError message does not contain the codeframe anymore and only the message, (string) $error will print the codeframe.
This revert #202 (commit 9d37f4c) because trying to parse PSR-7 request
was a mistake. The whole point of PSR-7 is to allow for interoperability
and be able to use specialized libs for body parsing (amongst many other
things). Trying to parse ourselves would be opening a can of worm if/when
other content types have to be supported. It is more correct and future
safe to require that the body is parsed before being passed to GraphQL.
Because PSR-7 specification only specify that `getParsedBody()` **may**
return the parsed body for `application/json`, we cannot assume that it
is always the case. So if the value returned parsed body is an empty array,
it means we should try to parse it ourselves (`null` would mean no body at
all according to spec).
With this modification we try to used given parsed body, but fallback on
trying to parse the body if necessary. This leave the door open to custom
implementation of parsing if needed, while making it easier to use out of
the box.
