browser_oxide 0.1.3

Stealth headless browser engine in Rust: real HTML/CSS/DOM/JS, V8 via deno_core, own BoringSSL TLS/JA4 fingerprint, no Chromium, no CDP — for anti-bot web scraping, archival, and AI agents
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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319

//! Canvas 2D path operations — `arc`, `arcTo`, `bezierCurveTo`,
//! `quadraticCurveTo`, `closePath`, `setTransform`, `resetTransform`,
//! `ellipse`, and `strokeText` are wired to Skia-backed implementations
//! in `crates/canvas/src/canvas2d.rs`. `arcTo` uses Skia's
//! `arc_to_tangent` (matches Chrome's `Path::arcTo`). `ellipse` uses a
//! bezier approximation (4·tan(seg/4) per segment, ⌈|sweep|/(π/2)⌉
//! segments) that matches Blink's `Path::AddEllipse` algorithm.
//! These tests verify both that the ops execute without throwing AND
//! that the resulting raster has the right pixel coverage — the bar for
//! anti-bot canvas fingerprint probes (challenge-vendor sensor scripts
//! and open-source FP suites such as CreepJS `paintCanvas`).

use browser_oxide::Page;

async fn evaluate(js: &str) -> String {
    let mut page = Page::from_html(
        "<!DOCTYPE html><html><body></body></html>",
        None::<browser_oxide::stealth::StealthProfile>,
    )
    .await
    .unwrap();
    page.evaluate(js).unwrap_or_else(|e| format!("ERROR: {e}"))
}

#[tokio::test]
async fn arc_does_not_throw() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 100; c.height = 100;
        const ctx = c.getContext('2d');
        ctx.beginPath();
        ctx.arc(50, 50, 25, 0, Math.PI * 2, false);
        ctx.fill();
        'ok'
        ",
    )
    .await;
    assert_eq!(r, "ok");
}

#[tokio::test]
async fn bezier_curve_to_does_not_throw() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 100; c.height = 100;
        const ctx = c.getContext('2d');
        ctx.beginPath();
        ctx.moveTo(10, 10);
        ctx.bezierCurveTo(30, 0, 70, 0, 90, 50);
        ctx.stroke();
        'ok'
        ",
    )
    .await;
    assert_eq!(r, "ok");
}

#[tokio::test]
async fn quadratic_curve_to_does_not_throw() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 100; c.height = 100;
        const ctx = c.getContext('2d');
        ctx.beginPath();
        ctx.moveTo(10, 10);
        ctx.quadraticCurveTo(50, 0, 90, 50);
        ctx.stroke();
        'ok'
        ",
    )
    .await;
    assert_eq!(r, "ok");
}

#[tokio::test]
async fn close_path_does_not_throw() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 100; c.height = 100;
        const ctx = c.getContext('2d');
        ctx.beginPath();
        ctx.moveTo(10, 10);
        ctx.lineTo(50, 10);
        ctx.lineTo(50, 50);
        ctx.closePath();
        ctx.fill();
        'ok'
        ",
    )
    .await;
    assert_eq!(r, "ok");
}

#[tokio::test]
async fn set_transform_does_not_throw() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 100; c.height = 100;
        const ctx = c.getContext('2d');
        ctx.setTransform(2, 0, 0, 2, 10, 20);
        ctx.fillRect(0, 0, 30, 30);
        ctx.resetTransform();
        ctx.fillRect(0, 0, 10, 10);
        'ok'
        ",
    )
    .await;
    assert_eq!(r, "ok");
}

#[tokio::test]
async fn stroke_text_does_not_throw() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 200; c.height = 50;
        const ctx = c.getContext('2d');
        ctx.font = '14px Arial';
        ctx.strokeText('Hello', 10, 30);
        'ok'
        ",
    )
    .await;
    assert_eq!(r, "ok");
}

/// arcTo executes via op_canvas_arc_to → Skia's arc_to_tangent (matches
/// Chrome's Path::arcTo at the Skia layer). Must produce a non-blank
/// raster — the previous lineTo-approximation produced a thin polygon,
/// the real arc fills a curved region.
#[tokio::test]
#[allow(non_snake_case, reason = "mirrors JS API name under test")]
async fn arcTo_renders_arc_pixels() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 100; c.height = 100;
        const ctx = c.getContext('2d');
        ctx.lineWidth = 4;
        ctx.beginPath();
        ctx.moveTo(20, 20);
        ctx.arcTo(80, 20, 80, 80, 20);
        ctx.lineTo(80, 80);
        ctx.stroke();
        const id = ctx.getImageData(0, 0, 100, 100);
        let nonzero = 0;
        for (let i = 3; i < id.data.length; i += 4) if (id.data[i] > 0) nonzero++;
        // The stroked rounded-corner path should mark several hundred pixels.
        nonzero > 200
        ",
    )
    .await;
    assert_eq!(r, "true");
}

/// Ellipse executes via op_canvas_ellipse → bezier-approximated rotated
/// ellipse. Filling a 30x20 ellipse at center (50,50) should mark
/// approximately π·30·20 ≈ 1885 pixels (with anti-aliasing slightly
/// inflating the count).
#[tokio::test]
async fn ellipse_filled_marks_expected_pixel_area() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 100; c.height = 100;
        const ctx = c.getContext('2d');
        ctx.fillStyle = '#000';
        ctx.beginPath();
        ctx.ellipse(50, 50, 30, 20, 0, 0, Math.PI * 2);
        ctx.fill();
        const id = ctx.getImageData(0, 0, 100, 100);
        let nonzero = 0;
        for (let i = 3; i < id.data.length; i += 4) if (id.data[i] > 0) nonzero++;
        // π·rx·ry = π·30·20 ≈ 1885. Allow ±25% for rasterization edges.
        nonzero > 1400 && nonzero < 2400
        ",
    )
    .await;
    assert_eq!(r, "true");
}

/// Rotated ellipse: a 30x10 ellipse rotated 90° should occupy a different
/// pixel set than the unrotated one (the bounding box differs).
#[tokio::test]
async fn ellipse_rotation_changes_bounding_box() {
    let r = evaluate(
        "
        function fillCount(rotation) {
            const c = document.createElement('canvas');
            c.width = 100; c.height = 100;
            const ctx = c.getContext('2d');
            ctx.fillStyle = '#000';
            ctx.beginPath();
            ctx.ellipse(50, 50, 30, 10, rotation, 0, Math.PI * 2);
            ctx.fill();
            // Sample a vertical line through the center: rotated ellipse
            // should fill more rows here than unrotated.
            const id = ctx.getImageData(50, 0, 1, 100);
            let n = 0;
            for (let i = 3; i < id.data.length; i += 4) if (id.data[i] > 0) n++;
            return n;
        }
        // Unrotated: y-extent = ±ry = ±10 → ~20 rows on the center column.
        // Rotated 90°: y-extent = ±rx = ±30 → ~60 rows.
        const unrotated = fillCount(0);
        const rotated = fillCount(Math.PI / 2);
        rotated > unrotated + 20
        ",
    )
    .await;
    assert_eq!(r, "true");
}

/// strokeText must trace glyph outlines (via ttf-parser) and stroke
/// them with the current strokeStyle/lineWidth — NOT alias to fillText.
/// A bot detector that calls both at the same position and compares
/// pixel counts catches a fillText alias trivially. This test renders
/// both and asserts the pixel sets are non-trivially different.
#[tokio::test]
async fn stroke_text_pixels_differ_from_fill_text() {
    let r = evaluate(
        "
        function render(method) {
            const c = document.createElement('canvas');
            c.width = 200; c.height = 50;
            const ctx = c.getContext('2d');
            ctx.font = '32px Arial';
            ctx.fillStyle = '#000';
            ctx.strokeStyle = '#000';
            ctx.lineWidth = 2;
            ctx[method]('Hello', 10, 35);
            const data = ctx.getImageData(0, 0, 200, 50).data;
            let nonzero = 0;
            for (let i = 3; i < data.length; i += 4) if (data[i] > 0) nonzero++;
            return nonzero;
        }
        const filled = render('fillText');
        const stroked = render('strokeText');
        // If aliased, stroked === filled. Real strokeText traces only
        // the contour at lineWidth=2 — for 'Hello' at 32px this is
        // visibly different (typically more outline pixels because the
        // stroke is 2 px wide on both sides of every edge, vs filled
        // interior which has hollow centers in 'l', 'o', 'e'). Assert
        // the absolute difference is at least 20% of the smaller count.
        const diff = Math.abs(stroked - filled);
        const smaller = Math.min(stroked, filled);
        const ratio = diff / Math.max(smaller, 1);
        ratio > 0.2 ? 'differs' : ('similar:filled=' + filled + ',stroked=' + stroked)
        ",
    )
    .await;
    assert_eq!(
        r, "differs",
        "strokeText must produce a visibly different pixel set than fillText"
    );
}

/// strokeText must respond to `lineWidth` — wider stroke produces more
/// pixels. This proves the stroke is genuinely tracing contours with
/// the current paint width, not just rendering filled glyphs.
#[tokio::test]
async fn stroke_text_responds_to_line_width() {
    let r = evaluate(
        "
        function render(lineWidth) {
            const c = document.createElement('canvas');
            c.width = 200; c.height = 50;
            const ctx = c.getContext('2d');
            ctx.font = '32px Arial';
            ctx.strokeStyle = '#000';
            ctx.lineWidth = lineWidth;
            ctx.strokeText('Hello', 10, 35);
            const data = ctx.getImageData(0, 0, 200, 50).data;
            let nonzero = 0;
            for (let i = 3; i < data.length; i += 4) if (data[i] > 0) nonzero++;
            return nonzero;
        }
        const thin = render(0.5);
        const thick = render(4);
        // Wider stroke must produce more covered pixels.
        thick > thin * 1.3 ? 'thicker' : ('not-thicker:thin=' + thin + ',thick=' + thick)
        ",
    )
    .await;
    assert_eq!(r, "thicker");
}

/// Composite test: full CreepJS-style scene with paths + text. Asserts
/// `toDataURL()` produces a non-trivial PNG (length > 1000 bytes).
#[tokio::test]
async fn complex_path_scene_produces_pixels() {
    let r = evaluate(
        "
        const c = document.createElement('canvas');
        c.width = 220; c.height = 30;
        const ctx = c.getContext('2d');
        ctx.textBaseline = 'top';
        ctx.font = \"14px 'Arial'\";
        ctx.textBaseline = 'alphabetic';
        ctx.fillStyle = '#f60';
        ctx.fillRect(125, 1, 62, 20);
        ctx.fillStyle = '#069';
        ctx.fillText('Cwm fjordbank glyphs vext quiz', 2, 15);
        ctx.beginPath();
        ctx.arc(50, 15, 10, 0, Math.PI * 2);
        ctx.fillStyle = 'rgba(102, 204, 0, 0.7)';
        ctx.fill();
        const url = c.toDataURL();
        url.length > 100 && url.startsWith('data:image/png')
        ",
    )
    .await;
    assert_eq!(r, "true");
}