netspd 0.1.7

A beautiful, modern, minimalistic network speed testing terminal application
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

//! Unit tests for the metric calculators.

use std::time::{Duration, Instant};

use netspd::engine::metrics::{statistics, Ema, LatencyCalculator, Sampler, ThroughputMeter};

const TOLERANCE: f64 = 1e-9;

fn close(a: f64, b: f64) -> bool {
    (a - b).abs() < TOLERANCE
}

#[test]
fn ema_seeds_with_first_sample() {
    let mut ema = Ema::new(0.5);
    assert!(ema.value().is_none());
    assert!(close(ema.update(10.0), 10.0));
}

#[test]
fn ema_smooths_toward_new_samples() {
    let mut ema = Ema::new(0.5);
    ema.update(10.0);
    assert!(close(ema.update(20.0), 15.0));
    assert!(close(ema.update(20.0), 17.5));
}

#[test]
fn ema_reset_clears_state() {
    let mut ema = Ema::new(0.3);
    ema.update(42.0);
    ema.reset();
    assert!(ema.value().is_none());
}

#[test]
fn ema_clamps_invalid_alpha() {
    let mut ema = Ema::new(5.0);
    ema.update(10.0);
    // Alpha clamped to 1.0: follows samples exactly.
    assert!(close(ema.update(30.0), 30.0));
}

#[test]
fn sampler_evicts_oldest_beyond_capacity() {
    let mut sampler = Sampler::new(3);
    for value in [1.0, 2.0, 3.0, 4.0] {
        sampler.push(value);
    }
    assert_eq!(sampler.len(), 3);
    let values: Vec<f64> = sampler.iter().collect();
    assert_eq!(values, vec![2.0, 3.0, 4.0]);
    assert_eq!(sampler.latest(), Some(4.0));
    assert_eq!(sampler.max(), Some(4.0));
}

#[test]
fn sampler_clear_keeps_capacity_working() {
    let mut sampler = Sampler::new(2);
    sampler.push(1.0);
    sampler.clear();
    assert!(sampler.is_empty());
    sampler.push(5.0);
    assert_eq!(sampler.latest(), Some(5.0));
}

#[test]
fn statistics_mean_median_stddev() {
    let values = [2.0, 4.0, 4.0, 4.0, 5.0, 5.0, 7.0, 9.0];
    assert!(close(statistics::mean(&values).unwrap_or(0.0), 5.0));
    assert!(close(statistics::median(&values).unwrap_or(0.0), 4.5));
    assert!(close(statistics::std_dev(&values).unwrap_or(0.0), 2.0));
}

#[test]
fn statistics_empty_inputs_yield_none() {
    assert!(statistics::mean(&[]).is_none());
    assert!(statistics::median(&[]).is_none());
    assert!(statistics::std_dev(&[]).is_none());
    assert!(statistics::successive_diff_mean(&[1.0]).is_none());
    assert!(statistics::trimmed(&[], 0.1).is_empty());
}

#[test]
fn statistics_trimmed_removes_outliers() {
    let values = [100.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 0.0];
    let trimmed = statistics::trimmed(&values, 0.1);
    assert_eq!(trimmed.len(), 8);
    assert!(!trimmed.contains(&100.0));
    assert!(!trimmed.contains(&0.0));
}

#[test]
fn statistics_jitter_is_mean_successive_difference() {
    let values = [10.0, 12.0, 9.0, 13.0];
    // |12-10| + |9-12| + |13-9| = 2 + 3 + 4 = 9; 9 / 3 = 3.
    assert!(close(
        statistics::successive_diff_mean(&values).unwrap_or(0.0),
        3.0
    ));
}

#[test]
fn latency_calculator_aggregates_and_counts_loss() {
    let mut calc = LatencyCalculator::new();
    for sample in [10.0, 11.0, 12.0, 13.0] {
        calc.record(sample);
    }
    calc.record_failure();
    let stats = calc.stats();
    assert!(stats.is_some());
    let Some(stats) = stats else { return };
    assert_eq!(stats.samples, 4);
    assert!(close(stats.min_ms, 10.0));
    assert!(close(stats.max_ms, 13.0));
    assert!(close(stats.packet_loss_pct, 20.0));
    assert!(stats.jitter_ms > 0.0);
}

#[test]
fn latency_calculator_rejects_invalid_samples() {
    let mut calc = LatencyCalculator::new();
    calc.record(f64::NAN);
    calc.record(-5.0);
    assert!(calc.stats().is_none());
    assert_eq!(calc.sample_count(), 0);
}

#[test]
fn throughput_meter_computes_speeds() {
    let start = Instant::now();
    let mut meter = ThroughputMeter::new(start, 1.0);
    // 1_000_000 bytes over exactly one second = 8 Mbps.
    let snapshot = meter.update(1_000_000, start + Duration::from_secs(1));
    assert!(close(snapshot.current_bps, 8_000_000.0));
    assert!(close(snapshot.average_bps, 8_000_000.0));
    assert!(close(snapshot.peak_bps, 8_000_000.0));
}

#[test]
fn throughput_meter_tracks_peak() {
    let start = Instant::now();
    let mut meter = ThroughputMeter::new(start, 1.0);
    meter.update(2_000_000, start + Duration::from_secs(1));
    let slower = meter.update(2_500_000, start + Duration::from_secs(2));
    assert!(slower.current_bps < slower.peak_bps);
    assert!(close(slower.peak_bps, 16_000_000.0));
}