Unary Tests

Unary tests are the expressions used in DMN input cells. They test whether the current input value (referred to as ?) satisfies a condition.

Usage

import { unaryTest } from '@veridtools/feel-runner'

// The context must include "?" — the input value being tested
unaryTest('[18..65]', { '?': 30 }).value   // true
unaryTest('"A","B","C"', { '?': 'B' }).value  // true
unaryTest('> 100', { '?': 50 }).value     // false

Single value

5         → matches if ? = 5
"approved" → matches if ? = "approved"

Range

[1..10]   → inclusive on both ends
(1..10)   → exclusive on both ends
[1..10)   → inclusive start, exclusive end
(1..10]   → exclusive start, inclusive end

Open-ended range

> 100
>= 100
< 18
<= 65

Disjunction (OR)

Multiple conditions separated by commas — any match returns true:

1, 2, 3               → any of these values
"A", "B", "C"         → any of these strings
< 18, > 65            → outside the range 18-65
1, [5..10], 20        → value 1, or 5 through 10, or 20

Negation

not(5)          → ? ≠ 5
not([1..10])    → ? outside 1..10
not("A","B")    → ? is not "A" or "B"

Any value

-    → always matches (wildcard)

Context references

Unary tests can reference variables from the context:

unaryTest('> threshold', { '?': 10, threshold: 5 }).value  // true

Null semantics

• null input against any non-null test: null (indeterminate)
• null input against null test: true