Flow: enable 'sketchy-null-bool' lint rule (#2371)

Author: IvanGoncharov

.flowconfig

@@ -10,7 +10,7 @@
 [libs]
 
 [lints]
-sketchy-null-bool=off
+sketchy-null-bool=error
 sketchy-null-string=error
 sketchy-null-number=error
 sketchy-null-mixed=error
@@ -35,6 +35,7 @@ uninitialized-instance-property=error
 include_warnings=true
 module.use_strict=true
 babel_loose_array_spread=true
+esproposal.optional_chaining=enable
 suppress_comment=\\(.\\|\n\\)*\\$FlowFixMe\\($\\|[^(]\\|(\\(<VERSION>\\)?)\\)
 suppress_comment=\\(.\\|\n\\)*\\$DisableFlowOnNegativeTest
 

src/error/GraphQLError.js

@@ -99,8 +99,7 @@ export class GraphQLError extends Error {
     // Compute locations in the source for the given nodes/positions.
     let _source = source;
     if (!_source && _nodes) {
-      const node = _nodes[0];
-      _source = node && node.loc && node.loc.source;
+      _source = _nodes[0].loc?.source;
     }
 
     let _positions = positions;
@@ -188,7 +187,7 @@ export class GraphQLError extends Error {
     });
 
     // Include (non-enumerable) stack trace.
-    if (originalError && originalError.stack) {
+    if (originalError?.stack) {
       Object.defineProperty(this, 'stack', {
         value: originalError.stack,
         writable: true,

src/error/__tests__/GraphQLError-test.js

@@ -19,7 +19,7 @@ const source = new Source(dedent`
 `);
 const ast = parse(source);
 const operationNode = ast.definitions[0];
-invariant(operationNode && operationNode.kind === Kind.OPERATION_DEFINITION);
+invariant(operationNode.kind === Kind.OPERATION_DEFINITION);
 const fieldNode = operationNode.selectionSet.selections[0];
 invariant(fieldNode);
 
@@ -161,7 +161,7 @@ describe('printError', () => {
       ),
     );
     const opA = docA.definitions[0];
-    invariant(opA && opA.kind === Kind.OBJECT_TYPE_DEFINITION && opA.fields);
+    invariant(opA.kind === Kind.OBJECT_TYPE_DEFINITION && opA.fields);
     const fieldA = opA.fields[0];
 
     const docB = parse(
@@ -175,7 +175,7 @@ describe('printError', () => {
       ),
     );
     const opB = docB.definitions[0];
-    invariant(opB && opB.kind === Kind.OBJECT_TYPE_DEFINITION && opB.fields);
+    invariant(opB.kind === Kind.OBJECT_TYPE_DEFINITION && opB.fields);
     const fieldB = opB.fields[0];
 
     const error = new GraphQLError('Example error with two nodes', [

src/error/locatedError.js

@@ -16,15 +16,15 @@ export function locatedError(
 ): GraphQLError {
   // Note: this uses a brand-check to support GraphQL errors originating from
   // other contexts.
-  if (originalError && Array.isArray(originalError.path)) {
+  if (Array.isArray(originalError.path)) {
     return (originalError: any);
   }
 
   return new GraphQLError(
-    originalError && originalError.message,
-    (originalError && (originalError: any).nodes) || nodes,
-    originalError && (originalError: any).source,
-    originalError && (originalError: any).positions,
+    originalError.message,
+    (originalError: any).nodes || nodes,
+    (originalError: any).source,
+    (originalError: any).positions,
     path,
     originalError,
   );

src/execution/__tests__/executor-test.js

@@ -292,7 +292,7 @@ describe('Execute: Handles basic execution tasks', () => {
     );
 
     const operation = document.definitions[0];
-    invariant(operation && operation.kind === Kind.OPERATION_DEFINITION);
+    invariant(operation.kind === Kind.OPERATION_DEFINITION);
 
     expect(resolvedInfo).to.include({
       fieldName: 'test',
@@ -1025,7 +1025,7 @@ describe('Execute: Handles basic execution tasks', () => {
       name: 'SpecialType',
       isTypeOf(obj, context) {
         const result = obj instanceof Special;
-        return context && context.async ? Promise.resolve(result) : result;
+        return context?.async ? Promise.resolve(result) : result;
       },
       fields: { value: { type: GraphQLString } },
     });

src/execution/execute.js

@@ -296,7 +296,7 @@ export function buildExecutionContext(
             ];
           }
           operation = definition;
-        } else if (definition.name && definition.name.value === operationName) {
+        } else if (definition.name?.value === operationName) {
           operation = definition;
         }
         break;
@@ -554,7 +554,7 @@ function shouldIncludeNode(
     node,
     exeContext.variableValues,
   );
-  if (skip && skip.if === true) {
+  if (skip?.if === true) {
     return false;
   }
 
@@ -563,7 +563,7 @@ function shouldIncludeNode(
     node,
     exeContext.variableValues,
   );
-  if (include && include.if === false) {
+  if (include?.if === false) {
     return false;
   }
   return true;

src/execution/values.js

@@ -50,7 +50,7 @@ export function getVariableValues(
   inputs: { +[variable: string]: mixed, ... },
   options?: {| maxErrors?: number |},
 ): CoercedVariableValues {
-  const maxErrors = options && options.maxErrors;
+  const maxErrors = options?.maxErrors;
   const errors = [];
   try {
     const coerced = coerceVariableValues(schema, varDefNodes, inputs, error => {

src/jsutils/isPromise.js

@@ -9,5 +9,5 @@ declare function isPromise(value: mixed): boolean %checks(value instanceof
 
 // eslint-disable-next-line no-redeclare
 export default function isPromise(value) {
-  return value != null && typeof value.then === 'function';
+  return typeof value?.then === 'function';
 }

src/language/__tests__/visitor-test.js

@@ -500,7 +500,7 @@ describe('Visitor', () => {
           'enter',
           node.kind,
           key,
-          parent && parent.kind != null ? parent.kind : undefined,
+          parent?.kind != null ? parent.kind : undefined,
         ]);
 
         checkVisitorFnArgs(ast, arguments);
@@ -512,7 +512,7 @@ describe('Visitor', () => {
           'leave',
           node.kind,
           key,
-          parent && parent.kind != null ? parent.kind : undefined,
+          parent?.kind != null ? parent.kind : undefined,
         ]);
 
         expect(argsStack.pop()).to.deep.equal([...arguments]);

src/language/parser.js

@@ -164,7 +164,7 @@ export function parseType(
 }
 
 class Parser {
-  _options: ParseOptions;
+  _options: ?ParseOptions;
   _lexer: Lexer;
 
   constructor(source: string | Source, options?: ParseOptions) {
@@ -175,12 +175,7 @@ class Parser {
     );
 
     this._lexer = new Lexer(sourceObj);
-    this._options = options || {
-      noLocation: false,
-      allowLegacySDLEmptyFields: false,
-      allowLegacySDLImplementsInterfaces: false,
-      experimentalFragmentVariables: false,
-    };
+    this._options = options;
   }
 
   /**
@@ -483,7 +478,7 @@ class Parser {
     // Experimental support for defining variables within fragments changes
     // the grammar of FragmentDefinition:
     //   - fragment FragmentName VariableDefinitions? on TypeCondition Directives? SelectionSet
-    if (this._options.experimentalFragmentVariables) {
+    if (this._options?.experimentalFragmentVariables === true) {
       return {
         kind: Kind.FRAGMENT_DEFINITION,
         name: this.parseFragmentName(),
@@ -869,7 +864,7 @@ class Parser {
       } while (
         this.expectOptionalToken(TokenKind.AMP) ||
         // Legacy support for the SDL?
-        (this._options.allowLegacySDLImplementsInterfaces &&
+        (this._options?.allowLegacySDLImplementsInterfaces === true &&
           this.peek(TokenKind.NAME))
       );
     }
@@ -882,7 +877,7 @@ class Parser {
   parseFieldsDefinition(): Array<FieldDefinitionNode> {
     // Legacy support for the SDL?
     if (
-      this._options.allowLegacySDLEmptyFields &&
+      this._options?.allowLegacySDLEmptyFields === true &&
       this.peek(TokenKind.BRACE_L) &&
       this._lexer.lookahead().kind === TokenKind.BRACE_R
     ) {
@@ -1403,7 +1398,7 @@ class Parser {
    * the source that created a given parsed object.
    */
   loc(startToken: Token): Location | void {
-    if (!this._options.noLocation) {
+    if (this._options?.noLocation !== true) {
       return new Location(
         startToken,
         this._lexer.lastToken,