self-assert / Requirements
Requirements
A collection of common rule requirements.
It also provides a way to compose requirements using the and, or and not functions.
Comparison
| Function | Description |
|---|---|
| identical | Returns a predicate that checks if the value is equal to the expected value. |
| differentFrom | Returns a predicate that checks if the value is not equal to the forbidden value. |
| isIn | Returns a predicate that checks if the value is in the allowed set. |
| isNotIn | Returns a predicate that checks if the value is not in the forbidden set. |
Composition
Methods for composing requirements. Example:
ts
const myRequirement = Requirements.and(
Requirements.greaterThan(0),
(value) => value % 42 === 0
);
console.log(myRequirement(0)); // false
console.log(myRequirement(42)); // true| Function | Description |
|---|---|
| and | Combines multiple conditions using logical AND |
| or | Combines multiple conditions using logical OR |
| not | Negates a condition |
Lists
| Function | Description |
|---|---|
| hasExactly | Returns a predicate that holds when the list has exactly the given number of elements |
| isEmpty | Returns a predicate that holds when the list has no elements |
| isNotEmpty | Returns a predicate that holds when the list has at least one element |
| hasMoreThan | Returns a predicate that holds when the list has more than the given number of elements |
| hasAtMost | Returns a predicate that holds when the list has at most the given number of elements |
| hasLessThan | Returns a predicate that holds when the list has less than the given number of elements |
| hasAtLeast | Returns a predicate that holds when the list has at least the given number of elements |
| includes | Returns a predicate that holds when the list contains the given element |
| doesNotInclude | Opposite of includes |
| allSatisfy | Returns a predicate that holds when all elements of the list satisfy the given condition |
| anySatisfy | Returns a predicate that holds when any element of the list satisfies the given condition |
| noneSatisfy | Returns a predicate that holds when no element of the list satisfies the given condition. Opposite of anySatisfy |
Numbers
| Function | Description |
|---|---|
| greaterThan | Returns a predicate that is true if the value is greater than the given number |
| greaterThanOrEqual | Returns a predicate that is true if the value is greater than or equal to the given number |
| lessThan | Returns a predicate that is true if the value is less than the given number |
| lessThanOrEqual | Returns a predicate that is true if the value is less than or equal to the given number |
| between | Returns a predicate that is true if the value is between two numbers (inclusive) |
| isInteger | Returns a predicate that is true if the value is an integer |
| isFloat | Returns a predicate that is true if the value is a float |
| isPositive | Returns a predicate that is true if the value is positive |
| isNegative | Returns a predicate that is true if the value is negative |
| isPositiveInteger | Returns a predicate that is true if the value is a positive integer |
| isNegativeInteger | Returns a predicate that is true if the value is a negative integer |
| isIntegerBetween | Returns a predicate that is true if the value is an integer between two numbers (inclusive) |
Strings
| Function | Description |
|---|---|
| isBlank | A predicate that evaluates to true if the string is empty or contains only whitespace characters. |
| isNotBlank | Opposite of isBlank. |
Others
| Function | Description |
|---|---|
| hold | A predicate that always evaluates to true. |
| fail | A predicate that always evaluates to false. |