Remove and partially deprecate Node's custom inspect funtion

Author: IvanGoncharov

src/jsutils/__tests__/inspect-test.js

@@ -3,7 +3,6 @@ import { describe, it } from 'mocha';
 
 import inspect from '../inspect';
 import invariant from '../invariant';
-import nodejsCustomInspectSymbol from '../nodejsCustomInspectSymbol';
 
 describe('inspect', () => {
   it('undefined', () => {
@@ -84,54 +83,40 @@ describe('inspect', () => {
     expect(inspect(map)).to.equal('{ a: true, b: null }');
   });
 
-  it('custom inspect', () => {
+  it('use toJSON if provided', () => {
     const object = {
-      inspect() {
-        return '<custom inspect>';
+      toJSON() {
+        return '<json value>';
       },
     };
 
-    expect(inspect(object)).to.equal('<custom inspect>');
+    expect(inspect(object)).to.equal('<json value>');
   });
 
-  it('custom inspect that return `this` should work', () => {
+  it('handles toJSON that return `this` should work', () => {
     const object = {
-      inspect() {
+      toJSON() {
         return this;
       },
     };
 
-    expect(inspect(object)).to.equal('{ inspect: [function inspect] }');
+    expect(inspect(object)).to.equal('{ toJSON: [function toJSON] }');
   });
 
-  it('custom symbol inspect is take precedence', () => {
+  it('handles toJSON returning object values', () => {
     const object = {
-      // istanbul ignore next (Never called and use just as a placeholder)
-      inspect() {
-        invariant(false);
-      },
-      [String(nodejsCustomInspectSymbol)]() {
-        return '<custom symbol inspect>';
-      },
-    };
-
-    expect(inspect(object)).to.equal('<custom symbol inspect>');
-  });
-
-  it('custom inspect returning object values', () => {
-    const object = {
-      inspect() {
-        return { custom: 'inspect' };
+      toJSON() {
+        return { json: 'value' };
       },
     };
 
-    expect(inspect(object)).to.equal('{ custom: "inspect" }');
+    expect(inspect(object)).to.equal('{ json: "value" }');
   });
 
-  it('custom inspect function that uses this', () => {
+  it('handles toJSON function that uses this', () => {
     const object = {
       str: 'Hello World!',
-      inspect() {
+      toJSON() {
         return this.str;
       },
     };
@@ -160,11 +145,11 @@ describe('inspect', () => {
     expect(inspect(mixed)).to.equal('{ array: [[Circular]] }');
 
     const customA = {
-      inspect: () => customB,
+      toJSON: () => customB,
     };
 
     const customB = {
-      inspect: () => customA,
+      toJSON: () => customA,
     };
 
     expect(inspect(customA)).to.equal('[Circular]');

src/jsutils/defineInspect.js

@@ -1,5 +1,4 @@
 /* eslint-disable flowtype/no-weak-types */
-import nodejsCustomInspectSymbol from './nodejsCustomInspectSymbol';
 
 const MAX_ARRAY_LENGTH = 10;
 const MAX_RECURSIVE_DEPTH = 2;
@@ -36,16 +35,15 @@ function formatObjectValue(
   }
 
   const seenValues = [...previouslySeenValues, value];
-  const customInspectFn = getCustomFn(value);
 
-  if (customInspectFn !== undefined) {
-    const customValue = customInspectFn.call(value);
+  if (typeof value.toJSON === 'function') {
+    const jsonValue = value.toJSON(value);
 
     // check for infinite recursion
-    if (customValue !== value) {
-      return typeof customValue === 'string'
-        ? customValue
-        : formatValue(customValue, seenValues);
+    if (jsonValue !== value) {
+      return typeof jsonValue === 'string'
+        ? jsonValue
+        : formatValue(jsonValue, seenValues);
     }
   } else if (Array.isArray(value)) {
     return formatArray(value, seenValues);
@@ -98,18 +96,6 @@ function formatArray(array: Array<mixed>, seenValues: Array<mixed>): string {
   return '[' + items.join(', ') + ']';
 }
 
-function getCustomFn(object: Object) {
-  const customInspectFn = object[String(nodejsCustomInspectSymbol)];
-
-  if (typeof customInspectFn === 'function') {
-    return customInspectFn;
-  }
-
-  if (typeof object.inspect === 'function') {
-    return object.inspect;
-  }
-}
-
 function getObjectTag(object: Object): string {
   const tag = Object.prototype.toString
     .call(object)

src/jsutils/inspect.js

@@ -1,6 +1,3 @@
-// eslint-disable-next-line import/no-nodejs-modules
-import { inspect as nodeInspect } from 'util';
-
 import { expect } from 'chai';
 import { describe, it } from 'mocha';
 
@@ -121,9 +118,6 @@ describe('Lexer', () => {
     expect(JSON.stringify(token)).to.equal(
       '{"kind":"Name","value":"foo","line":1,"column":1}',
     );
-    expect(nodeInspect(token)).to.equal(
-      "{ kind: 'Name', value: 'foo', line: 1, column: 1 }",
-    );
     expect(inspect(token)).to.equal(
       '{ kind: "Name", value: "foo", line: 1, column: 1 }',
     );

src/jsutils/nodejsCustomInspectSymbol.js

@@ -1,6 +1,3 @@
-// eslint-disable-next-line import/no-nodejs-modules
-import { inspect as nodeInspect } from 'util';
-
 import { expect } from 'chai';
 import { describe, it } from 'mocha';
 
@@ -379,7 +376,6 @@ describe('Parser', () => {
     const result = parse('{ id }');
 
     expect(JSON.stringify(result.loc)).to.equal('{"start":0,"end":6}');
-    expect(nodeInspect(result.loc)).to.equal('{ start: 0, end: 6 }');
     expect(inspect(result.loc)).to.equal('{ start: 0, end: 6 }');
   });
 

src/language/__tests__/lexer-test.js

@@ -1,5 +1,3 @@
-import defineInspect from '../jsutils/defineInspect';
-
 import type { Source } from './source';
 import type { TokenKindEnum } from './tokenKind';
 
@@ -44,10 +42,13 @@ export class Location {
   toJSON(): {| start: number, end: number |} {
     return { start: this.start, end: this.end };
   }
-}
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(Location);
+  // @deprecated: Will be removed in v17
+  // $FlowFixMe[unsupported-syntax] Flow doesn't support computed properties yet
+  [Symbol.for('nodejs.util.inspect.custom')](): mixed {
+    return this.toJSON();
+  }
+}
 
 /**
  * Represents a range of characters represented by a lexical token
@@ -124,10 +125,13 @@ export class Token {
       column: this.column,
     };
   }
-}
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(Token);
+  // @deprecated: Will be removed in v17
+  // $FlowFixMe[unsupported-syntax] Flow doesn't support computed properties yet
+  [Symbol.for('nodejs.util.inspect.custom')](): mixed {
+    return this.toJSON();
+  }
+}
 
 /**
  * @internal

src/language/__tests__/parser-test.js

@@ -17,7 +17,6 @@ import instanceOf from '../jsutils/instanceOf';
 import didYouMean from '../jsutils/didYouMean';
 import isObjectLike from '../jsutils/isObjectLike';
 import identityFunc from '../jsutils/identityFunc';
-import defineInspect from '../jsutils/defineInspect';
 import suggestionList from '../jsutils/suggestionList';
 
 import { GraphQLError } from '../error/GraphQLError';
@@ -370,9 +369,6 @@ export class GraphQLList<+T: GraphQLType> {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLList);
-
 /**
  * Non-Null Type Wrapper
  *
@@ -419,9 +415,6 @@ export class GraphQLNonNull<+T: GraphQLNullableType> {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLNonNull);
-
 /**
  * These types wrap and modify other types
  */
@@ -638,9 +631,6 @@ export class GraphQLScalarType {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLScalarType);
-
 export type GraphQLScalarSerializer<TExternal> = (
   outputValue: mixed,
 ) => ?TExternal;
@@ -782,9 +772,6 @@ export class GraphQLObjectType {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLObjectType);
-
 function defineInterfaces(
   config: $ReadOnly<
     | GraphQLObjectTypeConfig<mixed, mixed>
@@ -1100,9 +1087,6 @@ export class GraphQLInterfaceType {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLInterfaceType);
-
 export type GraphQLInterfaceTypeConfig<TSource, TContext> = {|
   name: string,
   description?: ?string,
@@ -1207,9 +1191,6 @@ export class GraphQLUnionType {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLUnionType);
-
 function defineTypes(
   config: $ReadOnly<GraphQLUnionTypeConfig<mixed, mixed>>,
 ): Array<GraphQLObjectType> {
@@ -1385,9 +1366,6 @@ export class GraphQLEnumType /* <T> */ {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLEnumType);
-
 function didYouMeanEnumValue(
   enumType: GraphQLEnumType,
   unknownValueStr: string,
@@ -1536,9 +1514,6 @@ export class GraphQLInputObjectType {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLInputObjectType);
-
 function defineInputFieldMap(
   config: $ReadOnly<GraphQLInputObjectTypeConfig>,
 ): GraphQLInputFieldMap {

src/language/ast.js

@@ -6,7 +6,6 @@ import toObjMap from '../jsutils/toObjMap';
 import devAssert from '../jsutils/devAssert';
 import instanceOf from '../jsutils/instanceOf';
 import isObjectLike from '../jsutils/isObjectLike';
-import defineInspect from '../jsutils/defineInspect';
 
 import type { DirectiveDefinitionNode } from '../language/ast';
 import type { DirectiveLocationEnum } from '../language/directiveLocation';
@@ -114,9 +113,6 @@ export class GraphQLDirective {
   }
 }
 
-// Print a simplified form when appearing in `inspect` and `util.inspect`.
-defineInspect(GraphQLDirective);
-
 export type GraphQLDirectiveConfig = {|
   name: string,
   description?: ?string,