Add Servo scroll snapshots

crates/ely_servo_host/tests/sidecar.rs

@@ -20,6 +20,10 @@ const PRD_SITE_COMPATIBILITY_SIZES: &[FrameSize] = &[
     FrameSize { width: 934, height: 657 },
     FrameSize { width: 1614, height: 980 },
 ];
+const SERVO_SCROLL_SITE: PrdSiteCompatibilityCase =
+    PrdSiteCompatibilityCase { url: "https://servo.org", title_fragment: "Servo" };
+const SERVO_SCROLL_SIZE: FrameSize = FrameSize { width: 934, height: 657 };
+const SERVO_SCROLL_OFFSET: ScrollOffset = ScrollOffset { x: 0, y: 480 };
 
 struct PrdSiteCompatibilityCase {
     url: &'static str,
@@ -32,38 +36,81 @@ struct FrameSize {
     height: u64,
 }
 
+#[derive(Clone, Copy)]
+struct ScrollOffset {
+    x: i64,
+    y: i64,
+}
+
+impl ScrollOffset {
+    const ZERO: Self = Self { x: 0, y: 0 };
+}
+
 #[test]
 fn sidecar_snapshots_prd_sites_to_rgba_files() -> Result<(), Box<dyn Error>> {
     for case in PRD_SITE_COMPATIBILITY_CASES {
         for size in PRD_SITE_COMPATIBILITY_SIZES {
-            snapshot_prd_site(case, *size)?;
+            snapshot_prd_site(case, *size, ScrollOffset::ZERO)?;
         }
     }
 
     Ok(())
 }
 
+#[test]
+fn sidecar_scrolls_prd_site_with_servo_input() -> Result<(), Box<dyn Error>> {
+    let initial_report =
+        snapshot_prd_site(&SERVO_SCROLL_SITE, SERVO_SCROLL_SIZE, ScrollOffset::ZERO)?;
+    let scrolled_report =
+        snapshot_prd_site(&SERVO_SCROLL_SITE, SERVO_SCROLL_SIZE, SERVO_SCROLL_OFFSET)?;
+
+    assert_eq!(report_field_as_i64(&scrolled_report, "scroll_x")?, SERVO_SCROLL_OFFSET.x);
+    assert_eq!(report_field_as_i64(&scrolled_report, "scroll_y")?, SERVO_SCROLL_OFFSET.y);
+    assert_eq!(
+        report_field_as_u64(&scrolled_report, "width")?,
+        SERVO_SCROLL_SIZE.width,
+        "{}",
+        SERVO_SCROLL_SITE.url
+    );
+    assert!(
+        report_field_as_bool(&scrolled_report, "scroll_changed_frame")?,
+        "{}",
+        SERVO_SCROLL_SITE.url
+    );
+    assert_ne!(
+        report_field_as_u64(&initial_report, "sample_hash")?,
+        report_field_as_u64(&scrolled_report, "sample_hash")?,
+        "{}",
+        SERVO_SCROLL_SITE.url
+    );
+
+    Ok(())
+}
+
 fn snapshot_prd_site(
     case: &PrdSiteCompatibilityCase,
     size: FrameSize,
-) -> Result<(), Box<dyn Error>> {
+    scroll_offset: ScrollOffset,
+) -> Result<serde_json::Value, Box<dyn Error>> {
     let site_name = case
         .url
         .chars()
         .map(|character| if character.is_ascii_alphanumeric() { character } else { '-' })
         .collect::<String>();
     let output_path = std::env::temp_dir().join(format!(
-        "ely-servo-sidecar-{}-{site_name}-{}x{}.rgba",
+        "ely-servo-sidecar-{}-{site_name}-{}x{}-{}-{}.rgba",
         std::process::id(),
         size.width,
-        size.height
+        size.height,
+        scroll_offset.x,
+        scroll_offset.y
     ));
 
     if output_path.exists() {
         std::fs::remove_file(&output_path)?;
     }
 
-    let output = run_sidecar_snapshot(case.url, &output_path, size)?;
+    let output = run_sidecar_snapshot(case.url, &output_path, size, scroll_offset)?;
 
     assert!(
         output.status.success(),
@@ -97,15 +144,17 @@ fn snapshot_prd_site(
     assert_eq!(std::fs::metadata(&output_path)?.len(), size.width * size.height * 4);
 
     std::fs::remove_file(&output_path)?;
-    Ok(())
+    Ok(report)
 }
 
 fn run_sidecar_snapshot(
     site_url: &str,
     output_path: &std::path::Path,
     size: FrameSize,
+    scroll_offset: ScrollOffset,
 ) -> Result<Output, Box<dyn Error>> {
-    let mut child = Command::new(env!("CARGO_BIN_EXE_ely_servo_sidecar"))
+    let mut command = Command::new(env!("CARGO_BIN_EXE_ely_servo_sidecar"));
+    command
         .arg("snapshot")
         .arg("--url")
         .arg(site_url)
@@ -114,10 +163,15 @@ fn run_sidecar_snapshot(
         .arg("--width")
         .arg(size.width.to_string())
         .arg("--height")
-        .arg(size.height.to_string())
-        .stdout(Stdio::piped())
-        .stderr(Stdio::piped())
-        .spawn()?;
+        .arg(size.height.to_string());
+    if scroll_offset.x != 0 {
+        command.arg("--scroll-x").arg(scroll_offset.x.to_string());
+    }
+    if scroll_offset.y != 0 {
+        command.arg("--scroll-y").arg(scroll_offset.y.to_string());
+    }
+
+    let mut child = command.stdout(Stdio::piped()).stderr(Stdio::piped()).spawn()?;
 
     let started_at = Instant::now();
     loop {
@@ -162,6 +216,26 @@ fn assert_report_text_contains(
     Ok(())
 }
 
+fn report_field_as_bool(
+    report: &serde_json::Value,
+    field: &'static str,
+) -> Result<bool, Box<dyn Error>> {
+    report
+        .get(field)
+        .and_then(serde_json::Value::as_bool)
+        .ok_or_else(|| format!("missing boolean report field: {field}").into())
+}
+
+fn report_field_as_i64(
+    report: &serde_json::Value,
+    field: &'static str,
+) -> Result<i64, Box<dyn Error>> {
+    report
+        .get(field)
+        .and_then(serde_json::Value::as_i64)
+        .ok_or_else(|| format!("missing signed report field: {field}").into())
+}
+
 fn report_field_as_u64(
     report: &serde_json::Value,
     field: &'static str,