After realizing how powerful GraphQL AST traversal could be, I explored the possibility of generating boilerplate code from any GraphQL schema. This project was inspired by apollo-codegen, which generates GraphQL client implementations for various languages.
The majority of the heavy lifting comes from the visit function in GraphQL's official JavaScript implementation. It provides a simple API for parsing a GraphQL schema by subscribing to enter/leave events for each type of GraphQL AST node.
The visit function also allows for an AST node to be modified when it is visited, which was the approach I used initially. Modifying the AST nodes resulted in a ~100 LoC implementation, as each node was reduced down to Dart syntax when visited, but it sacrificed code readability.
https://gist.github.com/johnsabath/2872101c7d11b48ac4a90eedaac94960
# The query root of GitHub's GraphQL interface.
type Query {
# Look up a code of conduct by its key
codeOfConduct(
# The code of conduct's key
key: String!
): CodeOfConduct
# Look up a code of conduct by its key
codesOfConduct: [CodeOfConduct]
# Look up an open source license by its key
license(
# The license's downcased SPDX ID
key: String!
): License
# Return a list of known open source licenses
licenses: [License]!
# Get alphabetically sorted list of Marketplace categories
marketplaceCategories(
# Exclude categories with no listings.
excludeEmpty: Boolean
): [MarketplaceCategory!]!
# Look up a Marketplace category by its slug.
marketplaceCategory(
# The URL slug of the category.
slug: String!
): MarketplaceCategory
# Look up a single Marketplace listing
marketplaceListing(
# Select the listing that matches this slug. It's the short name of the listing used in its URL.
slug: String!
): MarketplaceListing
# Look up Marketplace listings
marketplaceListings(
# Returns the first _n_ elements from the list.
first: Int
# Returns the elements in the list that come after the specified global ID.
after: String
# Returns the last _n_ elements from the list.
last: Int
# Returns the elements in the list that come before the specified global ID.
before: String
# Select only listings with the given category.
categorySlug: String
# Select listings to which user has admin access. If omitted, listings visible to the
# viewer are returned.
#
viewerCanAdmin: Boolean
# Select listings that can be administered by the specified user.
adminId: ID
# Select listings for products owned by the specified organization.
organizationId: ID
# Select listings visible to the viewer even if they are not approved. If omitted or
# false, only approved listings will be returned.
#
allStates: Boolean
# Select the listings with these slugs, if they are visible to the viewer.
slugs: [String]
# Select only listings where the primary category matches the given category slug.
primaryCategoryOnly: Boolean = false
# Select only listings that offer a free trial.
withFreeTrialsOnly: Boolean = false
): MarketplaceListingConnection!
# Return information about the GitHub instance
meta: GitHubMetadata!
# Fetches an object given its ID.
node(
# ID of the object.
id: ID!
): Node
# Lookup nodes by a list of IDs.
nodes(
# The list of node IDs.
ids: [ID!]!
): [Node]!
# Lookup a organization by login.
organization(
# The organization's login.
login: String!
): Organization
# The client's rate limit information.
rateLimit(
# If true, calculate the cost for the query without evaluating it
dryRun: Boolean = false
): RateLimit
# Hack to workaround https://github.com/facebook/relay/issues/112 re-exposing the root query object
relay: Query!
# Lookup a given repository by the owner and repository name.
repository(
# The login field of a user or organization
owner: String!
# The name of the repository
name: String!
): Repository
# Lookup a repository owner (ie. either a User or an Organization) by login.
repositoryOwner(
# The username to lookup the owner by.
login: String!
): RepositoryOwner
# Lookup resource by a URL.
resource(
# The URL.
url: URI!
): UniformResourceLocatable
# Perform a search across resources.
search(
# Returns the first _n_ elements from the list.
first: Int
# Returns the elements in the list that come after the specified global ID.
after: String
# Returns the last _n_ elements from the list.
last: Int
# Returns the elements in the list that come before the specified global ID.
before: String
# The search string to look for.
query: String!
# The types of search items to search within.
type: SearchType!
): SearchResultItemConnection!
# Look up a topic by name.
topic(
# The topic's name.
name: String!
): Topic
# Lookup a user by login.
user(
# The user's login.
login: String!
): User
# The currently authenticated user.
viewer: User!
}# The root query for implementing GraphQL mutations.
type Mutation {
# Applies a suggested topic to the repository.
acceptTopicSuggestion(
input: AcceptTopicSuggestionInput!
): AcceptTopicSuggestionPayload
# Adds a comment to an Issue or Pull Request.
addComment(input: AddCommentInput!): AddCommentPayload
# Adds a card to a ProjectColumn. Either `contentId` or `note` must be provided but **not** both.
addProjectCard(input: AddProjectCardInput!): AddProjectCardPayload
# Adds a column to a Project.
addProjectColumn(input: AddProjectColumnInput!): AddProjectColumnPayload
# Adds a review to a Pull Request.
addPullRequestReview(
input: AddPullRequestReviewInput!
): AddPullRequestReviewPayload
# Adds a comment to a review.
addPullRequestReviewComment(
input: AddPullRequestReviewCommentInput!
): AddPullRequestReviewCommentPayload
# Adds a reaction to a subject.
addReaction(input: AddReactionInput!): AddReactionPayload
# Adds a star to a Starrable.
addStar(input: AddStarInput!): AddStarPayload
# Creates a new project.
createProject(input: CreateProjectInput!): CreateProjectPayload
# Rejects a suggested topic for the repository.
declineTopicSuggestion(
input: DeclineTopicSuggestionInput!
): DeclineTopicSuggestionPayload
# Deletes a project.
deleteProject(input: DeleteProjectInput!): DeleteProjectPayload
# Deletes a project card.
deleteProjectCard(input: DeleteProjectCardInput!): DeleteProjectCardPayload
# Deletes a project column.
deleteProjectColumn(
input: DeleteProjectColumnInput!
): DeleteProjectColumnPayload
# Deletes a pull request review.
deletePullRequestReview(
input: DeletePullRequestReviewInput!
): DeletePullRequestReviewPayload
# Dismisses an approved or rejected pull request review.
dismissPullRequestReview(
input: DismissPullRequestReviewInput!
): DismissPullRequestReviewPayload
# Lock a lockable object
lockLockable(input: LockLockableInput!): LockLockablePayload
# Moves a project card to another place.
moveProjectCard(input: MoveProjectCardInput!): MoveProjectCardPayload
# Moves a project column to another place.
moveProjectColumn(input: MoveProjectColumnInput!): MoveProjectColumnPayload
# Removes outside collaborator from all repositories in an organization.
removeOutsideCollaborator(
input: RemoveOutsideCollaboratorInput!
): RemoveOutsideCollaboratorPayload
# Removes a reaction from a subject.
removeReaction(input: RemoveReactionInput!): RemoveReactionPayload
# Removes a star from a Starrable.
removeStar(input: RemoveStarInput!): RemoveStarPayload
# Set review requests on a pull request.
requestReviews(input: RequestReviewsInput!): RequestReviewsPayload
# Submits a pending pull request review.
submitPullRequestReview(
input: SubmitPullRequestReviewInput!
): SubmitPullRequestReviewPayload
# Updates an existing project.
updateProject(input: UpdateProjectInput!): UpdateProjectPayload
# Updates an existing project card.
updateProjectCard(input: UpdateProjectCardInput!): UpdateProjectCardPayload
# Updates an existing project column.
updateProjectColumn(
input: UpdateProjectColumnInput!
): UpdateProjectColumnPayload
# Updates the body of a pull request review.
updatePullRequestReview(
input: UpdatePullRequestReviewInput!
): UpdatePullRequestReviewPayload
# Updates a pull request review comment.
updatePullRequestReviewComment(
input: UpdatePullRequestReviewCommentInput!
): UpdatePullRequestReviewCommentPayload
# Updates viewers repository subscription state.
updateSubscription(input: UpdateSubscriptionInput!): UpdateSubscriptionPayload
# Replaces the repository's topics with the given topics.
updateTopics(input: UpdateTopicsInput!): UpdateTopicsPayload
}https://gist.github.com/johnsabath/f5507b3d5dae071808e1987f75053f49
abstract class Query {
CodeOfConduct codeOfConduct(String key);
List<CodeOfConduct> codesOfConduct;
License license(String key);
List<License> licenses;
List<MarketplaceCategory> marketplaceCategories(bool excludeEmpty);
MarketplaceCategory marketplaceCategory(String slug);
MarketplaceListing marketplaceListing(String slug);
MarketplaceListingConnection marketplaceListings(int first, String after, int last, String before, String categorySlug, bool viewerCanAdmin, String adminId, String organizationId, bool allStates, List<String> slugs, bool primaryCategoryOnly, bool withFreeTrialsOnly);
GitHubMetadata meta;
Node node(String id);
List<Node> nodes(List<String> ids);
Organization organization(String login);
RateLimit rateLimit(bool dryRun);
Query relay;
Repository repository(String owner, String name);
RepositoryOwner repositoryOwner(String login);
UniformResourceLocatable resource(dynamic url);
SearchResultItemConnection search(int first, String after, int last, String before, String query, SearchType type);
Topic topic(String name);
User user(String login);
User viewer;
}abstract class Mutation {
AcceptTopicSuggestionPayload acceptTopicSuggestion(AcceptTopicSuggestionInput input);
AddCommentPayload addComment(AddCommentInput input);
AddProjectCardPayload addProjectCard(AddProjectCardInput input);
AddProjectColumnPayload addProjectColumn(AddProjectColumnInput input);
AddPullRequestReviewPayload addPullRequestReview(AddPullRequestReviewInput input);
AddPullRequestReviewCommentPayload addPullRequestReviewComment(AddPullRequestReviewCommentInput input);
AddReactionPayload addReaction(AddReactionInput input);
AddStarPayload addStar(AddStarInput input);
CreateProjectPayload createProject(CreateProjectInput input);
DeclineTopicSuggestionPayload declineTopicSuggestion(DeclineTopicSuggestionInput input);
DeleteProjectPayload deleteProject(DeleteProjectInput input);
DeleteProjectCardPayload deleteProjectCard(DeleteProjectCardInput input);
DeleteProjectColumnPayload deleteProjectColumn(DeleteProjectColumnInput input);
DeletePullRequestReviewPayload deletePullRequestReview(DeletePullRequestReviewInput input);
DismissPullRequestReviewPayload dismissPullRequestReview(DismissPullRequestReviewInput input);
LockLockablePayload lockLockable(LockLockableInput input);
MoveProjectCardPayload moveProjectCard(MoveProjectCardInput input);
MoveProjectColumnPayload moveProjectColumn(MoveProjectColumnInput input);
RemoveOutsideCollaboratorPayload removeOutsideCollaborator(RemoveOutsideCollaboratorInput input);
RemoveReactionPayload removeReaction(RemoveReactionInput input);
RemoveStarPayload removeStar(RemoveStarInput input);
RequestReviewsPayload requestReviews(RequestReviewsInput input);
SubmitPullRequestReviewPayload submitPullRequestReview(SubmitPullRequestReviewInput input);
UpdateProjectPayload updateProject(UpdateProjectInput input);
UpdateProjectCardPayload updateProjectCard(UpdateProjectCardInput input);
UpdateProjectColumnPayload updateProjectColumn(UpdateProjectColumnInput input);
UpdatePullRequestReviewPayload updatePullRequestReview(UpdatePullRequestReviewInput input);
UpdatePullRequestReviewCommentPayload updatePullRequestReviewComment(UpdatePullRequestReviewCommentInput input);
UpdateSubscriptionPayload updateSubscription(UpdateSubscriptionInput input);
UpdateTopicsPayload updateTopics(UpdateTopicsInput input);
}