chore: expand inspect support of BSON types (#413)

Add a nodejs inspect symbol and `inspect` method to each BSON type.

NODE-2875

src/binary.ts

@@ -255,6 +255,16 @@ export class Binary {
     }
     return new Binary(data, type);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    const asBuffer = this.value(true);
+    return `Binary("${asBuffer.toString('hex')}", ${this.sub_type})`;
+  }
 }
 
 Object.defineProperty(Binary.prototype, '_bsontype', { value: 'Binary' });

src/code.ts

@@ -42,6 +42,16 @@ export class Code {
   static fromExtendedJSON(doc: CodeExtended): Code {
     return new Code(doc.$code, doc.$scope);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    const codeJson = this.toJSON();
+    return `Code("${codeJson.code}"${codeJson.scope ? `, ${JSON.stringify(codeJson.scope)}` : ''})`;
+  }
 }
 
 Object.defineProperty(Code.prototype, '_bsontype', { value: 'Code' });

src/db_ref.ts

@@ -98,6 +98,18 @@ export class DBRef {
     delete copy.$db;
     return new DBRef(doc.$ref, doc.$id, doc.$db, copy);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    // NOTE: if OID is an ObjectId class it will just print the oid string.
+    const oid =
+      this.oid === undefined || this.oid.toString === undefined ? this.oid : this.oid.toString();
+    return `DBRef("${this.namespace}", "${oid}"${this.db ? `, "${this.db}"` : ''})`;
+  }
 }
 
 Object.defineProperty(DBRef.prototype, '_bsontype', { value: 'DBRef' });

src/decimal128.ts

@@ -787,6 +787,15 @@ export class Decimal128 {
   static fromExtendedJSON(doc: Decimal128Extended): Decimal128 {
     return Decimal128.fromString(doc.$numberDecimal);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    return `Decimal128("${this.toString()}")`;
+  }
 }
 
 Object.defineProperty(Decimal128.prototype, '_bsontype', { value: 'Decimal128' });

src/double.ts

@@ -70,6 +70,16 @@ export class Double {
     const doubleValue = parseFloat(doc.$numberDouble);
     return options && options.relaxed ? doubleValue : new Double(doubleValue);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    const eJSON = this.toExtendedJSON() as DoubleExtended;
+    return `Double(${eJSON.$numberDouble})`;
+  }
 }
 
 Object.defineProperty(Double.prototype, '_bsontype', { value: 'Double' });

src/int_32.ts

@@ -50,6 +50,15 @@ export class Int32 {
   static fromExtendedJSON(doc: Int32Extended, options?: EJSONOptions): number | Int32 {
     return options && options.relaxed ? parseInt(doc.$numberInt, 10) : new Int32(doc.$numberInt);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    return `Int32(${this.valueOf()})`;
+  }
 }
 
 Object.defineProperty(Int32.prototype, '_bsontype', { value: 'Int32' });

src/long.ts

@@ -943,6 +943,15 @@ export class Long {
     const result = Long.fromString(doc.$numberLong);
     return options && options.relaxed ? result.toNumber() : result;
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    return `Long("${this.toString()}")`;
+  }
 }
 
 Object.defineProperty(Long.prototype, '__isLong__', { value: true });

src/max_key.ts

@@ -19,6 +19,15 @@ export class MaxKey {
   static fromExtendedJSON(): MaxKey {
     return new MaxKey();
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    return 'MaxKey()';
+  }
 }
 
 Object.defineProperty(MaxKey.prototype, '_bsontype', { value: 'MaxKey' });

src/min_key.ts

@@ -19,6 +19,15 @@ export class MinKey {
   static fromExtendedJSON(): MinKey {
     return new MinKey();
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    return 'MinKey()';
+  }
 }
 
 Object.defineProperty(MinKey.prototype, '_bsontype', { value: 'MinKey' });

src/symbol.ts

@@ -30,7 +30,7 @@ export class BSONSymbol {
 
   /** @internal */
   inspect(): string {
-    return this.value;
+    return `BSONSymbol("${this.value}")`;
   }
 
   /** @internal */
@@ -47,6 +47,11 @@ export class BSONSymbol {
   static fromExtendedJSON(doc: BSONSymbolExtended): BSONSymbol {
     return new BSONSymbol(doc.$symbol);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
 }
 
 Object.defineProperty(BSONSymbol.prototype, '_bsontype', { value: 'Symbol' });

src/timestamp.ts

@@ -1,7 +1,7 @@
 import { Long } from './long';
 
 /** @public */
-export type TimestampOverrides = '_bsontype' | 'toExtendedJSON' | 'fromExtendedJSON';
+export type TimestampOverrides = '_bsontype' | 'toExtendedJSON' | 'fromExtendedJSON' | 'inspect';
 /** @public */
 export type LongWithoutOverrides = new (low: number | Long, high?: number, unsigned?: boolean) => {
   [P in Exclude<keyof Long, TimestampOverrides>]: Long[P];
@@ -91,4 +91,13 @@ export class Timestamp extends LongWithoutOverridesClass {
   static fromExtendedJSON(doc: TimestampExtended): Timestamp {
     return new Timestamp(doc.$timestamp.i, doc.$timestamp.t);
   }
+
+  /** @internal */
+  [Symbol.for('nodejs.util.inspect.custom')](): string {
+    return this.inspect();
+  }
+
+  inspect(): string {
+    return `Timestamp(${this.getLowBits().toString()}, ${this.getHighBits().toString()})`;
+  }
 }

test/node/bson_test.js

@@ -18,6 +18,7 @@ const MaxKey = BSON.MaxKey;
 const { BinaryParser } = require('../binary_parser');
 const vm = require('vm');
 const { assertBuffersEqual } = require('./tools/utils');
+const { inspect } = require('util');
 
 /**
  * Module for parsing an ISO 8601 formatted string into a Date object.
@@ -2268,4 +2269,97 @@ describe('BSON', function () {
     expect(() => BSON.serialize(badArray)).to.throw();
     expect(() => BSON.serialize(badMap)).to.throw();
   });
+
+  describe('Should support util.inspect for', function () {
+    /**
+     * @ignore
+     */
+    it('Binary', function () {
+      const binary = new Binary(Buffer.from('0123456789abcdef0123456789abcdef', 'hex'), 4);
+      expect(inspect(binary)).to.equal('Binary("0123456789abcdef0123456789abcdef", 4)');
+    });
+
+    /**
+     * @ignore
+     */
+    it('BSONSymbol', function () {
+      const symbol = new BSONSymbol('sym');
+      expect(inspect(symbol)).to.equal('BSONSymbol("sym")');
+    });
+
+    /**
+     * @ignore
+     */
+    it('Code', function () {
+      const code = new Code('this.a > i', { i: 1 });
+      expect(inspect(code)).to.equal('Code("this.a > i", {"i":1})');
+    });
+
+    /**
+     * @ignore
+     */
+    it('DBRef', function () {
+      const oid = new ObjectId('deadbeefdeadbeefdeadbeef');
+      const dbref = new DBRef('namespace', oid, 'integration_tests_');
+      expect(inspect(dbref)).to.equal(
+        'DBRef("namespace", "deadbeefdeadbeefdeadbeef", "integration_tests_")'
+      );
+    });
+
+    /**
+     * @ignore
+     */
+    it('Decimal128', function () {
+      const dec = Decimal128.fromString('1.42');
+      expect(inspect(dec)).to.equal('Decimal128("1.42")');
+    });
+
+    /**
+     * @ignore
+     */
+    it('Double', function () {
+      const double = new Double(-42.42);
+      expect(inspect(double)).to.equal('Double(-42.42)');
+    });
+
+    /**
+     * @ignore
+     */
+    it('Int32', function () {
+      const int = new Int32(42);
+      expect(inspect(int)).to.equal('Int32(42)');
+    });
+
+    /**
+     * @ignore
+     */
+    it('Long', function () {
+      const long = Long.fromString('42');
+      expect(inspect(long)).to.equal('Long("42")');
+    });
+
+    /**
+     * @ignore
+     */
+    it('MaxKey', function () {
+      const maxKey = new MaxKey();
+      expect(inspect(maxKey)).to.equal('MaxKey()');
+    });
+
+    /**
+     * @ignore
+     */
+    it('MinKey', function () {
+      const minKey = new MinKey();
+      expect(inspect(minKey)).to.equal('MinKey()');
+    });
+
+    /**
+     * @ignore
+     */
+    it('Timestamp', function () {
+      const timestamp = new Timestamp(1, 100);
+      expect(inspect(timestamp)).to.equal('Timestamp(1, 100)');
+    });
+  });
 });