Improve modern layout and viewport rendering

crates/obscura-cli/tests/screenshot_after_eval.rs

@@ -0,0 +1,73 @@
+#![cfg(feature = "render")]
+
+use std::process::Command;
+
+fn output_directory() -> std::path::PathBuf {
+    let unique = std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .expect("clock")
+        .as_nanos();
+    std::env::temp_dir().join(format!(
+        "obscura-screenshot-after-eval-{}-{unique}",
+        std::process::id()
+    ))
+}
+
+#[test]
+fn screenshot_is_captured_after_eval_scrolls_the_live_page() {
+    let directory = output_directory();
+    std::fs::create_dir_all(&directory).expect("temporary output directory");
+    let top = directory.join("top.png");
+    let scrolled = directory.join("scrolled.png");
+    let url = concat!(
+        "data:text/html,<html style=\"margin:0\"><body style=\"margin:0\">",
+        "<div style=\"height:80px;background:red\"></div>",
+        "<div style=\"height:80px;background:blue\"></div>",
+        "</body></html>"
+    );
+
+    let run = |path: &std::path::Path, eval: Option<&str>| {
+        let mut command = Command::new(env!("CARGO_BIN_EXE_obscura"));
+        command
+            .args(["fetch", url, "--screenshot"])
+            .arg(path)
+            .args(["--wait", "0", "--timeout", "5", "--quiet"])
+            .env("OBSCURA_SHOT_W", "100")
+            .env("OBSCURA_SHOT_H", "80");
+        if let Some(expression) = eval {
+            command.args(["--eval", expression]);
+        }
+        command.output().expect("run obscura fetch")
+    };
+
+    let top_output = run(&top, None);
+    assert!(
+        top_output.status.success(),
+        "top capture failed: {}",
+        String::from_utf8_lossy(&top_output.stderr)
+    );
+
+    let scrolled_output = run(
+        &scrolled,
+        Some(
+            "(()=>{window.scrollTo(0,80);return JSON.stringify({y:window.scrollY})})()",
+        ),
+    );
+    assert!(
+        scrolled_output.status.success(),
+        "scrolled capture failed: {}",
+        String::from_utf8_lossy(&scrolled_output.stderr)
+    );
+    let state: serde_json::Value =
+        serde_json::from_slice(&scrolled_output.stdout).expect("evaluation state JSON");
+    assert_eq!(state["captureState"]["scrollY"].as_f64(), Some(80.0));
+
+    let top_bytes = std::fs::read(&top).expect("top PNG");
+    let scrolled_bytes = std::fs::read(&scrolled).expect("scrolled PNG");
+    assert_ne!(
+        top_bytes, scrolled_bytes,
+        "the post-eval screenshot must paint the scrolled viewport"
+    );
+
+    std::fs::remove_dir_all(directory).expect("remove temporary output directory");
+}