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
If a GraphQLError represents multiple nodes across files (could happen for validation across multiple parsed files) then the reported locations and printError output can be incorrect for the second node. This ensures locations are derived from nodes whenever possible to get correct location and amends comment documentation.
ref: graphql/graphql-js#1131
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.
A common case is encountering an error which blames to a single AST node. Ensure the GraphQLError constructor can handle this case.
ref: graphql/graphql-js#1123
