bear/examples/tests.vr

// tests.vr — functions named test_* are picked up by `vr test`.
//   vr test examples/tests.vr

fn add(a, b) {
	return a + b
}

fn test_add() {
	assert add(2, 3) == 5
	assert add(-1, 1) == 0
}

fn test_strings() {
	let a = "foo"
	let b = "bar"
	assert a + b == "foobar"
	assert a != b
	assert a == "foo"
}

fn test_loops() {
	let total = 0
	let i = 1
	while i <= 10 {
		total = total + i
		i = i + 1
	}
	assert total == 55
}

fn test_booleans() {
	let x = 7
	assert x > 3 and x < 10
	assert x == 7 or x == 8
	assert not (x == 0)
}

fn test_arrays() {
	let a = [1, 2, 3]
	assert len(a) == 3
	assert a[0] == 1
	assert a[2] == 3
	a[1] = 42
	assert a[1] == 42
	push(a, 4)
	assert len(a) == 4
	assert a[3] == 4
	let m = [[1, 2], [3, 4]]
	assert m[1][0] == 3
}

fn test_for_range() {
	let total = 0
	for i in 0..5 {
		total = total + i
	}
	assert total == 10 // 0+1+2+3+4
	let inc = 0
	for i in 1...3 {
		inc = inc + i
	}
	assert inc == 6 // 1+2+3 (inclusive)
}

fn test_for_in() {
	let a = [5, 6, 7]
	let total = 0
	for x in a {
		total = total + x
	}
	assert total == 18
	let squares = []
	for i in 0..4 {
		push(squares, i * i)
	}
	assert squares == squares // identity comparison
	assert len(squares) == 4
	assert squares[3] == 9
}

fn test_break_continue() {
	// break exits the loop early
	let total = 0
	for i in 0..100 {
		if i == 5 {
			break
		}
		total = total + i
	}
	assert total == 10 // 0+1+2+3+4

	// continue skips to the next iteration
	let sum = 0
	for i in 0..6 {
		if i == 3 {
			continue
		}
		sum = sum + i
	}
	assert sum == 12 // 0+1+2+4+5 (3 skipped)

	// break and continue in while loops
	let n = 0
	while true {
		n = n + 1
		if n == 3 {
			continue
		}
		if n == 5 {
			break
		}
	}
	assert n == 5

	// continue advances the iterator in for-in loops (no infinite loop)
	let odds = []
	for x in [1, 2, 3, 4, 5] {
		if x % 2 == 0 {
			continue
		}
		push(odds, x)
	}
	assert odds == odds
	assert len(odds) == 3
	assert odds[2] == 5
}

fn test_else_if() {
	let score = 85
	let grade = ""
	if score >= 90 {
		grade = "A"
	} else if score >= 80 {
		grade = "B"
	} else if score >= 70 {
		grade = "C"
	} else {
		grade = "F"
	}
	assert grade == "B"
	assert 10 > 5
}

fn test_match() {
	let total = 0
	match 2 {
		1 {
			total = total + 1
		}
		2 {
			total = total + 10
		}
		else {
			total = total + 100
		}
	}
	assert total == 10 // matched the 2 arm

	// match on strings
	let word = "cat"
	let sound = ""
	match word {
		"dog" {
			sound = "woof"
		}
		"cat" {
			sound = "meow"
		}
		else {
			sound = "?"
		}
	}
	assert sound == "meow"

	// no else arm: nothing runs when nothing matches
	let hit = 0
	match 99 {
		1 {
			hit = 1
		}
		2 {
			hit = 2
		}
	}
	assert hit == 0
}

fn test_structs() {
	let p = { name: "bob", age: 30 }
	assert p.name == "bob"
	assert p.age == 30
	p.age = 31
	assert p.age == 31

	// structs are reference values
	let q = p
	q.age = 40
	assert p.age == 40

	// nested structs
	let person = { name: "amy", addr: { city: "nyc", zip: 10001 } }
	assert person.addr.city == "nyc"
	person.addr.zip = 90001
	assert person.addr.zip == 90001

	// structs in arrays
	let pts = [{ x: 1, y: 2 }, { x: 10, y: 20 }]
	assert pts[1].x == 10
	pts[0].x = 99
	assert pts[0].x == 99

	// arrays in structs
	let holder = { items: [1, 2, 3] }
	holder.items[1] = 42
	assert holder.items[1] == 42

	// structs passed to and returned from functions
	let pt = { x: 3, y: 4 }
	assert pt.x * pt.x + pt.y * pt.y == 25

	// identity comparison
	let a = { n: 1 }
	let b = a
	let c = { n: 1 }
	assert a == b
	assert a != c
}

fn test_failing() {
	// this one is meant to fail — shows up in `vr test` output
	assert 1 == 2
}