> For the complete documentation index, see [llms.txt](https://testbox.ortusbooks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://testbox.ortusbooks.com/digging-deeper/expectations/set-expectations.md).

# Set Expectations

Matchers for BoxLang Set objects

BoxLang ships a native `Set` type. Asserting against one with array matchers means sorting first and hoping the ordering is stable, which obscures what the test actually means. TestBox 7.1 adds a family of matchers that speak set semantics directly.

{% hint style="info" %}
These matchers require BoxLang. They are not available on Lucee or Adobe ColdFusion.
{% endhint %}

## Creating Sets

Use the `setOf()` built-in to build a set inline:

```java
var roles = setOf( "admin", "editor", "viewer" )
```

## Membership And Equality

### `toBeASet()`

Asserts the actual value is a `Set`.

```java
expect( setOf( 1, 2 ) ).toBeASet()
expect( [ 1, 2 ] ).notToBeASet()
```

### `toEqualSet()`

Asserts two sets contain the same members. Order is irrelevant, which is the whole point of a set.

```java
expect( setOf( 1, 2 ) ).toEqualSet( setOf( 2, 1 ) )
```

## Subsets And Supersets

### `toBeSubsetOf()` / `toBeSupersetOf()`

```java
expect( setOf( "admin" ) ).toBeSubsetOf( setOf( "admin", "editor" ) )
expect( setOf( "admin", "editor" ) ).toBeSupersetOf( setOf( "admin" ) )
```

Use these for permission checks, where the assertion is "the granted roles include at least these" rather than an exact match.

### `toBeDisjointFrom()`

Asserts the two sets share no members at all.

```java
expect( setOf( "read" ) ).toBeDisjointFrom( setOf( "write", "delete" ) )
```

## Set Algebra

Each of these takes the other operand and the expected result.

### `toHaveUnion()`

```java
expect( setOf( 1 ) ).toHaveUnion( setOf( 2 ), setOf( 1, 2 ) )
```

### `toHaveIntersection()`

```java
expect( setOf( 1, 2 ) ).toHaveIntersection( setOf( 2, 3 ), setOf( 2 ) )
```

### `toHaveDifference()`

Members in the actual set that are not in the other set.

```java
expect( setOf( 1, 2 ) ).toHaveDifference( setOf( 2 ), setOf( 1 ) )
```

### `toHaveSymmetricDifference()`

Members in either set but not both.

```java
expect( setOf( 1, 2 ) ).toHaveSymmetricDifference( setOf( 2, 3 ), setOf( 1, 3 ) )
```

## Negated Forms

Every matcher here has a negated counterpart: `notToBeASet()`, `notToEqualSet()`, `notToBeSubsetOf()`, `notToBeSupersetOf()`, `notToHaveUnion()`, `notToHaveIntersection()`, `notToHaveDifference()` and `notToHaveSymmetricDifference()`.

## A Real Example

```java
describe( "Menu permissions", function(){

    it( "shows only the menu items the user may reach", function(){
        var visible = menuService.visibleFor( user )
        var granted = setOf( "dashboard", "reports" )

        expect( visible ).toBeASet()
        expect( visible ).toEqualSet( granted )
        expect( visible ).toBeDisjointFrom( setOf( "admin", "billing" ) )
    } )

} )
```


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