feat(NODE-5648): add Long.fromStringStrict() (#675)

aditi-khare-mongoDB · web-flow · commit 9d5a5dfe59aa · 2024-04-30T13:11:08.000-06:00
diff --git a/src/int_32.ts b/src/int_32.ts
@@ -3,6 +3,7 @@ import { BSON_INT32_MAX, BSON_INT32_MIN } from './constants';
 import { BSONError } from './error';
 import type { EJSONOptions } from './extended_json';
 import { type InspectFn, defaultInspect } from './parser/utils';
+import { removeLeadingZerosAndExplicitPlus } from './utils/string_utils';
 
 /** @public */
 export interface Int32Extended {
@@ -48,11 +49,7 @@ export class Int32 extends BSONValue {
    * @param value - the string we want to represent as an int32.
    */
   static fromString(value: string): Int32 {
-    const cleanedValue = !/[^0]+/.test(value)
-      ? value.replace(/^0+/, '0') // all zeros case
-      : value[0] === '-'
-        ? value.replace(/^-0+/, '-') // negative number with leading zeros
-        : value.replace(/^\+?0+/, ''); // positive number with leading zeros
+    const cleanedValue = removeLeadingZerosAndExplicitPlus(value);
 
     const coercedValue = Number(value);
 
diff --git a/src/long.ts b/src/long.ts
@@ -3,6 +3,7 @@ import { BSONError } from './error';
 import type { EJSONOptions } from './extended_json';
 import { type InspectFn, defaultInspect } from './parser/utils';
 import type { Timestamp } from './timestamp';
+import * as StringUtils from './utils/string_utils';
 
 interface LongWASMHelpers {
   /** Gets the high bits of the last operation performed */
@@ -246,29 +247,24 @@ export class Long extends BSONValue {
   }
 
   /**
+   * @internal
    * Returns a Long representation of the given string, written using the specified radix.
+   * Throws an error if `throwsError` is set to true and any of the following conditions are true:
+   *  - the string contains invalid characters for the given radix
+   *  - the string contains whitespace
    * @param str - The textual representation of the Long
    * @param unsigned - Whether unsigned or not, defaults to signed
    * @param radix - The radix in which the text is written (2-36), defaults to 10
    * @returns The corresponding Long value
    */
-  static fromString(str: string, unsigned?: boolean, radix?: number): Long {
+  private static _fromString(str: string, unsigned: boolean, radix: number): Long {
     if (str.length === 0) throw new BSONError('empty string');
-    if (str === 'NaN' || str === 'Infinity' || str === '+Infinity' || str === '-Infinity')
-      return Long.ZERO;
-    if (typeof unsigned === 'number') {
-      // For goog.math.long compatibility
-      (radix = unsigned), (unsigned = false);
-    } else {
-      unsigned = !!unsigned;
-    }
-    radix = radix || 10;
     if (radix < 2 || 36 < radix) throw new BSONError('radix');
 
     let p;
     if ((p = str.indexOf('-')) > 0) throw new BSONError('interior hyphen');
     else if (p === 0) {
-      return Long.fromString(str.substring(1), unsigned, radix).neg();
+      return Long._fromString(str.substring(1), unsigned, radix).neg();
     }
 
     // Do several (8) digits each time through the loop, so as to
@@ -291,6 +287,131 @@ export class Long extends BSONValue {
     return result;
   }
 
+  /**
+   * Returns a signed Long representation of the given string, written using radix 10.
+   * Will throw an error if the given text is not exactly representable as a Long.
+   * Throws an error if any of the following conditions are true:
+   * - the string contains invalid characters for the radix 10
+   * - the string contains whitespace
+   * - the value the string represents is too large or too small to be a Long
+   * Unlike Long.fromString, this method does not coerce '+/-Infinity' and 'NaN' to Long.Zero
+   * @param str - The textual representation of the Long
+   * @returns The corresponding Long value
+   */
+  static fromStringStrict(str: string): Long;
+  /**
+   * Returns a Long representation of the given string, written using the radix 10.
+   * Will throw an error if the given parameters are not exactly representable as a Long.
+   * Throws an error if any of the following conditions are true:
+   * - the string contains invalid characters for the given radix
+   * - the string contains whitespace
+   * - the value the string represents is too large or too small to be a Long
+   * Unlike Long.fromString, this method does not coerce '+/-Infinity' and 'NaN' to Long.Zero
+   * @param str - The textual representation of the Long
+   * @param unsigned - Whether unsigned or not, defaults to signed
+   * @returns The corresponding Long value
+   */
+  static fromStringStrict(str: string, unsigned?: boolean): Long;
+  /**
+   * Returns a signed Long representation of the given string, written using the specified radix.
+   * Will throw an error if the given parameters are not exactly representable as a Long.
+   * Throws an error if any of the following conditions are true:
+   * - the string contains invalid characters for the given radix
+   * - the string contains whitespace
+   * - the value the string represents is too large or too small to be a Long
+   * Unlike Long.fromString, this method does not coerce '+/-Infinity' and 'NaN' to Long.Zero
+   * @param str - The textual representation of the Long
+   * @param radix - The radix in which the text is written (2-36), defaults to 10
+   * @returns The corresponding Long value
+   */
+  static fromStringStrict(str: string, radix?: boolean): Long;
+  /**
+   * Returns a Long representation of the given string, written using the specified radix.
+   * Will throw an error if the given parameters are not exactly representable as a Long.
+   * Throws an error if any of the following conditions are true:
+   * - the string contains invalid characters for the given radix
+   * - the string contains whitespace
+   * - the value the string represents is too large or too small to be a Long
+   * Unlike Long.fromString, this method does not coerce '+/-Infinity' and 'NaN' to Long.Zero
+   * @param str - The textual representation of the Long
+   * @param unsigned - Whether unsigned or not, defaults to signed
+   * @param radix - The radix in which the text is written (2-36), defaults to 10
+   * @returns The corresponding Long value
+   */
+  static fromStringStrict(str: string, unsigned?: boolean, radix?: number): Long;
+  static fromStringStrict(str: string, unsignedOrRadix?: boolean | number, radix?: number): Long {
+    let unsigned = false;
+    if (typeof unsignedOrRadix === 'number') {
+      // For goog.math.long compatibility
+      (radix = unsignedOrRadix), (unsignedOrRadix = false);
+    } else {
+      unsigned = !!unsignedOrRadix;
+    }
+    radix ??= 10;
+
+    if (str.trim() !== str) {
+      throw new BSONError(`Input: '${str}' contains leading and/or trailing whitespace`);
+    }
+    if (!StringUtils.validateStringCharacters(str, radix)) {
+      throw new BSONError(`Input: '${str}' contains invalid characters for radix: ${radix}`);
+    }
+
+    // remove leading zeros (for later string comparison and to make math faster)
+    const cleanedStr = StringUtils.removeLeadingZerosAndExplicitPlus(str);
+
+    // check roundtrip result
+    const result = Long._fromString(cleanedStr, unsigned, radix);
+    if (result.toString(radix).toLowerCase() !== cleanedStr.toLowerCase()) {
+      throw new BSONError(
+        `Input: ${str} is not representable as ${result.unsigned ? 'an unsigned' : 'a signed'} 64-bit Long ${radix != null ? `with radix: ${radix}` : ''}`
+      );
+    }
+    return result;
+  }
+
+  /**
+   * Returns a signed Long representation of the given string, written using radix 10.
+   * @param str - The textual representation of the Long
+   * @returns The corresponding Long value
+   */
+  static fromString(str: string): Long;
+  /**
+   * Returns a signed Long representation of the given string, written using radix 10.
+   * @param str - The textual representation of the Long
+   * @param radix - The radix in which the text is written (2-36), defaults to 10
+   * @returns The corresponding Long value
+   */
+  static fromString(str: string, radix?: number): Long;
+  /**
+   * Returns a Long representation of the given string, written using radix 10.
+   * @param str - The textual representation of the Long
+   * @param unsigned - Whether unsigned or not, defaults to signed
+   * @returns The corresponding Long value
+   */
+  static fromString(str: string, unsigned?: boolean): Long;
+  /**
+   * Returns a Long representation of the given string, written using the specified radix.
+   * @param str - The textual representation of the Long
+   * @param unsigned - Whether unsigned or not, defaults to signed
+   * @param radix - The radix in which the text is written (2-36), defaults to 10
+   * @returns The corresponding Long value
+   */
+  static fromString(str: string, unsigned?: boolean, radix?: number): Long;
+  static fromString(str: string, unsignedOrRadix?: boolean | number, radix?: number): Long {
+    let unsigned = false;
+    if (typeof unsignedOrRadix === 'number') {
+      // For goog.math.long compatibility
+      (radix = unsignedOrRadix), (unsignedOrRadix = false);
+    } else {
+      unsigned = !!unsignedOrRadix;
+    }
+    radix ??= 10;
+    if (str === 'NaN' || str === 'Infinity' || str === '+Infinity' || str === '-Infinity') {
+      return Long.ZERO;
+    }
+    return Long._fromString(str, unsigned, radix);
+  }
+
   /**
    * Creates a Long from its byte representation.
    * @param bytes - Byte representation
diff --git a/src/utils/string_utils.ts b/src/utils/string_utils.ts
@@ -0,0 +1,44 @@
+/**
+ * @internal
+ * Removes leading zeros and explicit plus from textual representation of a number.
+ */
+export function removeLeadingZerosAndExplicitPlus(str: string): string {
+  if (str === '') {
+    return str;
+  }
+
+  let startIndex = 0;
+
+  const isNegative = str[startIndex] === '-';
+  const isExplicitlyPositive = str[startIndex] === '+';
+
+  if (isExplicitlyPositive || isNegative) {
+    startIndex += 1;
+  }
+
+  let foundInsignificantZero = false;
+
+  for (; startIndex < str.length && str[startIndex] === '0'; ++startIndex) {
+    foundInsignificantZero = true;
+  }
+
+  if (!foundInsignificantZero) {
+    return isExplicitlyPositive ? str.slice(1) : str;
+  }
+
+  return `${isNegative ? '-' : ''}${str.length === startIndex ? '0' : str.slice(startIndex)}`;
+}
+
+/**
+ * @internal
+ * Returns false for an string that contains invalid characters for its radix, else returns the original string.
+ * @param str - The textual representation of the Long
+ * @param radix - The radix in which the text is written (2-36), defaults to 10
+ */
+export function validateStringCharacters(str: string, radix?: number): false | string {
+  radix = radix ?? 10;
+  const validCharacters = '0123456789abcdefghijklmnopqrstuvwxyz'.slice(0, radix);
+  // regex is case insensitive and checks that each character within the string is one of the validCharacters
+  const regex = new RegExp(`[^-+${validCharacters}]`, 'i');
+  return regex.test(str) ? false : str;
+}
diff --git a/test/node/int_32_tests.js b/test/node/int_32_tests.js
@@ -108,7 +108,9 @@ describe('Int32', function () {
       ['a string with zero with leading zeros', '000000', 0],
       ['a string with positive leading zeros', '000000867', 867],
       ['a string with explicity positive leading zeros', '+000000867', 867],
-      ['a string with negative leading zeros', '-00007', -7]
+      ['a string with negative leading zeros', '-00007', -7],
+      ['a string with explicit positive zeros', '+000000', 0],
+      ['a string explicit positive no leading zeros', '+32', 32]
     ];
     const errorInputs = [
       ['Int32.max + 1', '2147483648', 'larger than the maximum value for Int32'],
diff --git a/test/node/long.test.ts b/test/node/long.test.ts
@@ -163,4 +163,120 @@ describe('Long', function () {
       });
     });
   });
+
+  describe('static fromString()', function () {
+    const successInputs: [
+      name: string,
+      input: string,
+      unsigned: boolean | undefined,
+      radix: number | undefined,
+      expectedStr?: string
+    ][] = [
+      ['Infinity', 'Infinity', false, 34, '0'],
+      ['-Infinity', '-Infinity', false, 23, '0'],
+      ['+Infinity', '+Infinity', false, 12, '0'],
+      ['NaN', 'NaN', false, 16, '0']
+    ];
+
+    for (const [testName, str, unsigned, radix, expectedStr] of successInputs) {
+      context(`when the input is ${testName}`, () => {
+        it(`should return a Long representation of the input`, () => {
+          expect(Long.fromString(str, unsigned, radix).toString(radix)).to.equal(
+            expectedStr ?? str.toLowerCase()
+          );
+        });
+      });
+    }
+  });
+
+  describe('static fromStringStrict()', function () {
+    const successInputs: [
+      name: string,
+      input: string,
+      unsigned: boolean | undefined,
+      radix: number | undefined,
+      expectedStr?: string
+    ][] = [
+      ['basic no alphabet low radix', '1236', true, 8],
+      ['negative basic no alphabet low radix', '-1236', false, 8],
+      ['valid upper and lower case letters in string with radix > 10', 'eEe', true, 15],
+      ['hexadecimal letters', '126073efbcdADEF', true, 16],
+      ['negative hexadecimal letters', '-1267efbcdDEF', false, 16],
+      ['negative leading zeros', '-00000032', false, 15, '-32'],
+      ['leading zeros', '00000032', false, 15, '32'],
+      ['explicit positive leading zeros', '+00000032', false, 15, '32'],
+      ['max unsigned binary input', Long.MAX_UNSIGNED_VALUE.toString(2), true, 2],
+      ['max unsigned decimal input', Long.MAX_UNSIGNED_VALUE.toString(10), true, 10],
+      ['max unsigned hex input', Long.MAX_UNSIGNED_VALUE.toString(16), true, 16],
+      ['max signed binary input', Long.MAX_VALUE.toString(2), false, 2],
+      ['max signed decimal input', Long.MAX_VALUE.toString(10), false, 10],
+      ['max signed hex input', Long.MAX_VALUE.toString(16), false, 16],
+      ['min signed binary input', Long.MIN_VALUE.toString(2), false, 2],
+      ['min signed decimal input', Long.MIN_VALUE.toString(10), false, 10],
+      ['min signed hex input', Long.MIN_VALUE.toString(16), false, 16],
+      ['signed zeros', '+000000', false, 10, '0'],
+      ['unsigned zero', '0', true, 10],
+      ['explicit positive no leading zeros', '+32', true, 10, '32'],
+      // the following inputs are valid radix 36 inputs, but will not represent NaN or +/- Infinity
+      ['radix 36 Infinity', 'Infinity', false, 36],
+      ['radix 36 -Infinity', '-Infinity', false, 36],
+      ['radix 36 +Infinity', '+Infinity', false, 36, 'infinity'],
+      ['radix 36 NaN', 'NaN', false, 36],
+      ['overload no unsigned and no radix parameter', '-32', undefined, undefined],
+      ['overload no unsigned parameter', '-32', undefined, 12],
+      ['overload no radix parameter', '32', true, undefined]
+    ];
+
+    const failureInputs: [
+      name: string,
+      input: string,
+      unsigned: boolean | undefined,
+      radix: number | undefined
+    ][] = [
+      ['empty string', '', true, 2],
+      ['invalid numbers in binary string', '234', true, 2],
+      ['non a-z or numeric string', '~~', true, 36],
+      ['alphabet in radix < 10', 'a', true, 9],
+      ['radix does not allow all alphabet letters', 'eee', false, 14],
+      ['over max unsigned binary input', Long.MAX_UNSIGNED_VALUE.toString(2) + '1', true, 2],
+      ['over max unsigned decimal input', Long.MAX_UNSIGNED_VALUE.toString(10) + '1', true, 10],
+      ['over max unsigned hex input', Long.MAX_UNSIGNED_VALUE.toString(16) + '1', true, 16],
+      ['over max signed binary input', Long.MAX_VALUE.toString(2) + '1', false, 2],
+      ['over max signed decimal input', Long.MAX_VALUE.toString(10) + '1', false, 10],
+      ['over max signed hex input', Long.MAX_VALUE.toString(16) + '1', false, 16],
+      ['under min signed binary input', Long.MIN_VALUE.toString(2) + '1', false, 2],
+      ['under min signed decimal input', Long.MIN_VALUE.toString(10) + '1', false, 10],
+      ['under min signed hex input', Long.MIN_VALUE.toString(16) + '1', false, 16],
+      ['string with whitespace', '      3503a  ', false, 11],
+      ['negative zero unsigned', '-0', true, 9],
+      ['negative zero signed', '-0', false, 13],
+      ['radix 1', '12', false, 1],
+      ['negative radix', '12', false, -4],
+      ['radix over 36', '12', false, 37],
+      // the following inputs are invalid radix 16 inputs
+      // this is because of the characters, not because of the values they commonly represent
+      ['radix 10 Infinity', 'Infinity', false, 10],
+      ['radix 10 -Infinity', '-Infinity', false, 10],
+      ['radix 10 +Infinity', '+Infinity', false, 10],
+      ['radix 10 NaN', 'NaN', false, 10],
+      ['overload no radix parameter and invalid sign', '-32', true, undefined]
+    ];
+
+    for (const [testName, str, unsigned, radix, expectedStr] of successInputs) {
+      context(`when the input is ${testName}`, () => {
+        it(`should return a Long representation of the input`, () => {
+          expect(Long.fromStringStrict(str, unsigned, radix).toString(radix)).to.equal(
+            expectedStr ?? str.toLowerCase()
+          );
+        });
+      });
+    }
+    for (const [testName, str, unsigned, radix] of failureInputs) {
+      context(`when the input is ${testName}`, () => {
+        it(`should throw BSONError`, () => {
+          expect(() => Long.fromStringStrict(str, unsigned, radix)).to.throw(BSONError);
+        });
+      });
+    }
+  });
 });
diff --git a/test/node/release.test.ts b/test/node/release.test.ts
@@ -48,6 +48,7 @@ const REQUIRED_FILES = [
   'src/utils/byte_utils.ts',
   'src/utils/node_byte_utils.ts',
   'src/utils/number_utils.ts',
+  'src/utils/string_utils.ts',
   'src/utils/web_byte_utils.ts',
   'src/utils/latin.ts',
   'src/parse_utf8.ts',
diff --git a/test/node/utils/string_utils.test.ts b/test/node/utils/string_utils.test.ts
