# All files / util types.ts

69.23% Statements 9/13
44.44% Branches 8/18
50% Functions 2/4
69.23% Lines 9/13

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82

    2x

    2x

    2x

    2x

    2x
    16699x

    2x
    4848x

    2x

     /**
     * Copyright 2017 Google Inc.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */

    import { AnyJs } from './misc';

    // Untyped Number alias we can use to check for ES6 methods / properties.
    // tslint:disable-next-line:no-any variable-name
    const NumberAsAny = Number as any;

    // An Object whose keys and values are strings.
    export type StringMap = { [key: string]: string };

    /**
     * Minimum safe integer in Javascript because of floating point precision.
     * Added to not rely on ES6 features.
     */
    export let MIN_SAFE_INTEGER: number =
      NumberAsAny.MIN_SAFE_INTEGER || -(Math.pow(2, 53) - 1);

    /**
     * Maximum safe integer in Javascript because of floating point precision.
     * Added to not rely on ES6 features.
     */
    export let MAX_SAFE_INTEGER: number =
      NumberAsAny.MAX_SAFE_INTEGER || Math.pow(2, 53) - 1;

    /**
     * Returns whether an number is an integer, uses native implementation if
     * available.
     * Added to not rely on ES6 features.
     * @param value The value to test for being an integer
     */
    export let isInteger: (value: AnyJs) => boolean =
      NumberAsAny.isInteger ||
      (value =>
        typeof value === 'number' &&
        isFinite(value) &&
        Math.floor(value) === value);

    /**
     * Returns whether a variable is either undefined or null.
     */
    export function isNullOrUndefined(value: AnyJs): boolean {
      return value === null || value === undefined;
    }

    /**
     * Returns whether a value is an integer and in the safe integer range
     * @param value The value to test for being an integer and in the safe range
     */
    export function isSafeInteger(value: AnyJs): boolean {
      return (
        isInteger(value) &&
        (value as number) <= MAX_SAFE_INTEGER &&
        (value as number) >= MIN_SAFE_INTEGER
      );
    }

    /**
     * Safely checks if the number is NaN.
     */
    export function safeIsNaN(value: AnyJs): boolean {
      if (NumberAsAny.IsNaN) {
        return NumberAsAny.IsNaN(value);
      } else {
        return typeof value === 'number' && isNaN(value);
      }
    }