Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Flow errors from imported npm package in buildAstSchema

See original GitHub issue

Using graphql-js version 14.0.2 and Flow version 0.87.0, Flow throws the following errors:

Error ┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈ node_modules/graphql/utilities/buildASTSchema.js.flow:363:9

Missing type annotation for V. V is a type parameter declared in function [1] and was implicitly
instantiated at call of keyValMap [2].

     node_modules/graphql/utilities/buildASTSchema.js.flow
     360│     def: ObjectTypeDefinitionNode | InterfaceTypeDefinitionNode,
     361│   ) {
     362│     return def.fields
 [2] 363│       ? keyValMap(
     364│           def.fields,
     365│           field => field.name.value,
     366│           field => this.buildField(field),
     367│         )
     368│       : {};
     369│   }
     370│

     node_modules/graphql/jsutils/keyValMap.js.flow
 [1]  29│ export default function keyValMap<T, V>(
      30│   list: $ReadOnlyArray<T>,
      31│   keyFn: (item: T) => string,
      32│   valFn: (item: T) => V,
      33│ ): ObjMap<V> {


Error ┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈ node_modules/graphql/utilities/buildASTSchema.js.flow:372:12

Missing type annotation for V. V is a type parameter declared in function [1] and was implicitly
instantiated at call of keyValMap [2].

     node_modules/graphql/utilities/buildASTSchema.js.flow
     369│   }
     370│
     371│   _makeInputValues(values: $ReadOnlyArray<InputValueDefinitionNode>) {
 [2] 372│     return keyValMap(
     373│       values,
     374│       value => value.name.value,
     375│       value => this.buildInputField(value),
     376│     );
     377│   }
     378│
     379│   _makeInterfaceDef(def: InterfaceTypeDefinitionNode) {

     node_modules/graphql/jsutils/keyValMap.js.flow
 [1]  29│ export default function keyValMap<T, V>(
      30│   list: $ReadOnlyArray<T>,
      31│   keyFn: (item: T) => string,
      32│   valFn: (item: T) => V,
      33│ ): ObjMap<V> {


Error ┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈ node_modules/graphql/utilities/buildASTSchema.js.flow:399:9

Missing type annotation for V. V is a type parameter declared in function [1] and was implicitly
instantiated at call of keyValMap [2].

     node_modules/graphql/utilities/buildASTSchema.js.flow
     396│
     397│   _makeValueDefMap(def: EnumTypeDefinitionNode) {
     398│     return def.values
 [2] 399│       ? keyValMap(
     400│           def.values,
     401│           enumValue => enumValue.name.value,
     402│           enumValue => this.buildEnumValue(enumValue),
     403│         )
     404│       : {};
     405│   }
     406│

     node_modules/graphql/jsutils/keyValMap.js.flow
 [1]  29│ export default function keyValMap<T, V>(
      30│   list: $ReadOnlyArray<T>,
      31│   keyFn: (item: T) => string,
      32│   valFn: (item: T) => V,
      33│ ): ObjMap<V> {

As a quick fix, I’ve added .*/node_modules/graphql/jsutils/keyValMap.js.flow to my .flowconfig, but this is far from ideal…