chore: switch to importing validation rules from graphql's public API

I'm looking into cleaning up how validation rules are exported in
`15.0.0`. So I decided to refactor this code and switch rules imports to
use `*Rule` that is public API instead of importing internal files
directly. Sadly we forget to expose `ExecutableDefinitions` rule in
public API but I will fix it in `15.0.0` and backport into `14.x.x`

packages/graphql-language-service-utils/src/validateWithCustomRules.ts

@@ -7,12 +7,19 @@
  *
  */
 
-import { DocumentNode, TypeDefinitionNode } from 'graphql/language';
-import { GraphQLError } from 'graphql/error';
-import { GraphQLSchema } from 'graphql/type';
 import { CustomValidationRule } from 'graphql-language-service-types';
 
-import { specifiedRules, TypeInfo, validate } from 'graphql';
+import {
+  DocumentNode,
+  Kind,
+  specifiedRules,
+  validate,
+  GraphQLError,
+  GraphQLSchema,
+  NoUnusedFragmentsRule,
+  KnownFragmentNamesRule,
+} from 'graphql';
+import { ExecutableDefinitions } from 'graphql/validation/rules/ExecutableDefinitions';
 
 /**
  * Validate a GraphQL Document optionally with custom validation rules.
@@ -23,54 +30,34 @@ export function validateWithCustomRules(
   customRules?: Array<CustomValidationRule>,
   isRelayCompatMode?: boolean,
 ): Array<GraphQLError> {
-  // Because every fragment is considered for determing model subsets that may
-  // be used anywhere in the codebase they're all technically "used" by clients
-  // of graphql-data. So we remove this rule from the validators.
-  const {
-    NoUnusedFragments,
-  } = require('graphql/validation/rules/NoUnusedFragments');
-  const {
-    ExecutableDefinitions,
-  } = require('graphql/validation/rules/ExecutableDefinitions');
-  const rulesToSkip = [NoUnusedFragments, ExecutableDefinitions];
-  if (isRelayCompatMode) {
-    const {
-      KnownFragmentNames,
-    } = require('graphql/validation/rules/KnownFragmentNames');
-    rulesToSkip.push(KnownFragmentNames);
-  }
-
-  const rules = specifiedRules.filter(
-    rule => !rulesToSkip.some(r => r === rule),
-  );
-
-  const typeInfo = new TypeInfo(schema);
+  const rules = specifiedRules.filter(rule => {
+    // Because every fragment is considered for determing model subsets that may
+    // be used anywhere in the codebase they're all technically "used" by clients
+    // of graphql-data. So we remove this rule from the validators.
+    if (rule === NoUnusedFragmentsRule && rule === ExecutableDefinitions) {
+      return false;
+    }
+    if (isRelayCompatMode && rule === KnownFragmentNamesRule) {
+      return false;
+    }
+    return true;
+  });
 
   if (customRules) {
     Array.prototype.push.apply(rules, customRules);
   }
 
-  const errors: Readonly<Array<GraphQLError>> = validate(
-    schema,
-    ast,
-    rules,
-    typeInfo,
-  );
-
-  if (errors.length > 0) {
-    return errors.filter(error => {
-      if (error.message.indexOf('Unknown directive') === -1) {
-        return true;
+  const errors = validate(schema, ast, rules);
+  return errors.filter(error => {
+    if (error.message.indexOf('Unknown directive') !== -1 && error.nodes) {
+      const node = error.nodes[0];
+      if (node && node.kind === Kind.DIRECTIVE) {
+        const name = node.name.value;
+        if (name === 'arguments' || name === 'argumentDefinitions') {
+          return false;
+        }
       }
-      if (error.nodes && (error.nodes[0] as TypeDefinitionNode)) {
-        const node = <TypeDefinitionNode>error.nodes[0];
-        return !(
-          (node.name && node.name.value === 'arguments') ||
-          node.name.value === 'argumentDefinitions'
-        );
-      }
-    });
-  }
-
-  return [];
+    }
+    return true;
+  });
 }