Extending Mocks

When you desire a more refined dataset from your mocks you have two levels of control you can exert:

1. Named Contexts -- you can tag properties in your model to a known "type"
2. Bespoke Handling -- you can write your own function for a given property in your model

Let's explore each of these separately.

Named Contexts

In the auto-mocking section we saw how a property named name would be automatically populated with a random name. What if you had a property called fathersName? Well that would NOT automatically be given a name but rather just a random string. This is a good example of where named contexts can be leveraged to give the fathersName property the same treatment as name.

Here's how we'd do that:

export class Person extends Model {
  @property public name: string;
  @property @mock("name") public fathersName: string;
}

with this simple addition you've told the mocking engine that the property fathersName should be treated as a name. Pretty cool right?

So the obvious next question is ... what named properties are there? Glad you're there keeping me honest. So the answer is:

• name
  • firstName
  • lastName
• company
  • companyName
  • catchPhrase
• address
  • streetName
  • streetAddress
  • city
  • county
  • state
  • stateAbbr
  • zipCode
  • country
  • countryCode
• latitude
• longitude
• gender
• date (alias for dateRecent)
  • datePast (or datePastString for string return instead of Date)
  • dateFuture (or dateFutureString for string return instead of Date)
  • dateRecent (or dateRecentString for string return instead of Date)
  • dateSoon (or dateSoonString for string return instead of Date)
• images
  • avatar
  • imageAnimal
  • imagePerson
  • imageNature
  • imageTransport
• phoneNumber
• lorem
  • word
  • words
  • sentence
  • slug
  • paragraph
  • paragraphs
  • url

All you need to do is choose any of the above and add the @mock([named tag]) as a modifier to the property. There are a few more named contexts which take additional params:

• number - mock("number", { min: 0, max: 1000, precision: 0 })
  • allows you to get a number of a any combination of a stated min, max, or precision.
  • if no parameter value is stated then the number will be between 1 and 100
  • if you want a number with two decimal places to the right then you'd set precision to .01
• price -mock("price", { min: 10, max: 1000, symbol: "£" })
  • the precision defaults to 2
  • The currency symbol default to "$" but can be set to whatever character you please
  • by default the "cents" component is always 0 but you can set it to a variant amount with {variableCents}: true}; when this is set it distributes 40% of values to 0 cents, 30% to 99 cents, and the remaining 30% to a random number
• random - @mock("random", ...arrayOfThings)
  • using a normal distribution, chooses one of the array items each time
• sequence = @mock("shuffle", ...arrayOfThings)
  • sequentially applies each array item and then repeats if none are left
• distribution = @mock("distribution", [40, "male"], [50, "female"], [10, "other])
  • similar to random but it allows you to state the percentage chance of each possible outcome
• placeImage - @mock("placeImage", width, heigh, type)
  • types are "animals", "architecture", "people", "nature", "people", and "tech". Default type is "any"
• placeHolder - @mock("placeHolder", size, backgroundColor, textColor)
  • size can be a single number like "300" which represents both height and width or it can separate height from width with "300x100"
  • backgroundColor and textColor are hex values like FFFFFF (white), 0000FF (blue), etc.

Bespoke Handling

The named contexts should take you a long way but sometimes not to the finish line. In these situations you can drop out of "configuration" and into code:

const myBespokeHandler: IMockHelper = (context) => {
  return context.faker...
}

export class Person extends Model {
  @property name: string;
  @property @mock(myBespokeHandler) fathersName: string;
}