// Flash-source test suite — the `test "name" { }` block form, exercised
// end to end: flashc transpiles this file and the emitted Zig's test blocks
// run under `zig build test-flash`. A failing expectation fails the build,
// exactly as a host unit test does.

use std

const Answer = 42

fn add(a i32, b i32) i32 {
    return a + b
}

fn double(xs []mut i32) void {
    for x, i in xs {
        xs[i] = x * 2
    }
}

// `defer { … }` mutating through an out-pointer: the block runs on scope
// exit, after the body's `*= 10`, so the caller observes both effects.
fn bump(p *mut i32) void {
    defer {
        p.* += 1
    }
    p.* *= 10
}

fn mustBePositive(n i32) !i32 {
    if n <= 0 {
        return error.NotPositive
    }
    return n
}

test "add sums two integers" {
    try std.testing.expectEqual(5, add(2, 3))
}

test "a short declaration and a file-scope const are visible in a test body" {
    sum := add(Answer, 0)
    try std.testing.expectEqual(42, sum)
}

test "an index-captured for loop mutates through a mut slice" {
    var buf [3]i32 = .{ 1, 2, 3 }
    double(buf[0..])
    try std.testing.expectEqual(6, buf[2])
}

test "a defer block runs on scope exit" {
    var n i32 = 1
    bump(&n)
    try std.testing.expectEqual(11, n)
}

test "an error return propagates to the expectation" {
    r := mustBePositive(-1)
    try std.testing.expectError(error.NotPositive, r)
    ok := try mustBePositive(7)
    try std.testing.expectEqual(7, ok)
}