Interface: IRawProperty<Ts, IsAsync>

Defined in: packages/fast-check/src/check/property/IRawProperty.ts:32

Property

A property is the combination of:

• Arbitraries: how to generate the inputs for the algorithm
• Predicate: how to confirm the algorithm succeeded?

Remarks

Since 1.19.0

Extended by

• IProperty
• IAsyncProperty

Type Parameters

Type Parameter	Default type
Ts	-
IsAsync extends boolean	boolean

Properties

runAfterEach

runAfterEach: () => IsAsync extends true ? Promise<void> : never | IsAsync extends false ? void : never

Defined in: packages/fast-check/src/check/property/IRawProperty.ts:81

Run after each hook

Returns

IsAsync extends true ? Promise<void> : never | IsAsync extends false ? void : never

Remarks

Since 3.4.0

---

runBeforeEach

runBeforeEach: () => IsAsync extends true ? Promise<void> : never | IsAsync extends false ? void : never

Defined in: packages/fast-check/src/check/property/IRawProperty.ts:75

Run before each hook

Returns

IsAsync extends true ? Promise<void> : never | IsAsync extends false ? void : never

Remarks

Since 3.4.0

Methods

generate()

generate(mrng, runId?): Value<Ts>

Defined in: packages/fast-check/src/check/property/IRawProperty.ts:49

Generate values of type Ts

Parameters

Parameter	Type	Description
mrng	Random	Random number generator
runId?	number	Id of the generation, starting at 0 - if set the generation might be biased

Returns

Value<Ts>

Remarks

Since 0.0.7 (return type changed in 3.0.0)

---

isAsync()

isAsync(): IsAsync

Defined in: packages/fast-check/src/check/property/IRawProperty.ts:39

Is the property asynchronous?

true in case of asynchronous property, false otherwise

Returns

IsAsync

Remarks

Since 0.0.7

---

run()

run(v): IsAsync extends true ? Promise<PreconditionFailure | PropertyFailure | null> : never | IsAsync extends false ? PreconditionFailure | PropertyFailure | null : never

Defined in: packages/fast-check/src/check/property/IRawProperty.ts:65

Check the predicate for v

Parameters

Parameter	Type	Description
v	Ts	Value of which we want to check the predicate

Returns

IsAsync extends true ? Promise<PreconditionFailure | PropertyFailure | null> : never | IsAsync extends false ? PreconditionFailure | PropertyFailure | null : never

Remarks

Since 0.0.7

---

shrink()

shrink(value): Stream<Value<Ts>>

Defined in: packages/fast-check/src/check/property/IRawProperty.ts:58

Shrink value of type Ts

Parameters

Parameter	Type	Description
value	Value<Ts>	The value to be shrunk, it can be context-less

Returns

Stream<Value<Ts>>

Remarks

Since 3.0.0