host: the core owns the event loop; every platform becomes a vtable of optional methods

1 files changed, 38 insertions, 18 deletions

diff --git a/test/web_harness.mjs b/test/web_harness.mjs
index 087dd91b..7bfc2d60 100644
--- a/test/web_harness.mjs
+++ b/test/web_harness.mjs
@@ -17,25 +17,47 @@ async function main() {
   const webDir = path.resolve(process.argv[2]);
   const wasmBytes = await fs.readFile(path.join(webDir, "pardes.wasm"));
   const module = await WebAssembly.compile(wasmBytes);
-  assert.deepEqual(WebAssembly.Module.imports(module), [], "the freestanding core must have no JS or libc imports");
-  const { exports: wasm } = await WebAssembly.instantiate(module, {});
+  const { DomRenderer, animationTicks, browserHost } = await import(pathToFileURL(path.join(webDir, "app.mjs")));
+  assert.deepEqual(
+    [...new Set(WebAssembly.Module.imports(module).map((entry) => entry.module))],
+    ["pardes"],
+    "the freestanding core must import nothing but the page's own host",
+  );
+
+  // The page's real import object, with every call recorded: the browser host
+  // is only what a page can actually do, and a replay must ask it for nothing.
+  const host = browserHost();
+  const asked = [];
+  for (const [name, fn] of Object.entries(host.imports.pardes)) {
+    host.imports.pardes[name] = (...args) => {
+      asked.push(name);
+      return fn(...args);
+    };
+  }
+  const { exports: wasm } = await WebAssembly.instantiate(module, host.imports);
+  host.wasm = wasm;
 
   for (const name of [
     "memory", "pardes_init", "pardes_frame", "pardes_frame_ptr", "pardes_key",
-    "pardes_mouse", "pardes_pointer_leave", "pardes_gui_tagline_font_percent", "pardes_output",
-    "pardes_lsp_response", "pardes_pipe_response", "pardes_file_changed",
-    "pardes_effect_next", "pardes_deinit",
+    "pardes_mouse", "pardes_pointer_leave", "pardes_gui_tagline_font_percent",
+    "pardes_paste", "pardes_tick", "pardes_animation_tick", "pardes_animating",
+    "pardes_should_quit", "pardes_deinit",
   ]) assert.ok(wasm[name], `missing wasm export ${name}`);
 
   assert.equal(wasm.pardes_init(80, 24), 0, `wasm init error ${wasm.pardes_last_error()}`);
+  assert.equal(wasm.pardes_frame(), 0, "a frame exists only once the core has presented one");
+  wasm.pardes_tick();
   assert.equal(wasm.pardes_frame(), 80 * 24);
   assert.ok(wasm.pardes_frame_ptr() > 0);
 
-  const { DomRenderer, animationTicks } = await import(pathToFileURL(path.join(webDir, "app.mjs")));
   const document = new FakeDocument();
   const root = document.createElement("main");
   root.ownerDocument = document;
   const renderer = new DomRenderer(root, wasm);
+  const draw = () => {
+    wasm.pardes_tick();
+    return renderer.render();
+  };
   const first = renderer.render();
 
   assert.equal(first.cols, 80);
@@ -69,7 +91,7 @@ async function main() {
   assert.equal(animationTicks(stalled, 60_000), 4, "suspended tab catch-up was not bounded");
 
   const firstCell = renderer.cells[0];
-  const second = renderer.render();
+  const second = draw();
   assert.equal(renderer.cells[0], firstCell, "stable frames should reuse DOM nodes");
   assert.equal(second.cells.length, 80 * 24);
 
@@ -77,7 +99,7 @@ async function main() {
   // over-scroll (the core clamps at row zero) so adding more source files does
   // not silently move the hard-coded build.zig click onto some later path.
   for (let tick = 0; tick < 128; tick += 1) wasm.pardes_mouse(3, 0, 5, 3, 0);
-  const listingTop = renderer.render();
+  const listingTop = draw();
   assert.match(
     listingTop.cells.map((cell) => cell.text).join(""),
     /git ls-files --cached --others --exclude-standard.*build\.zig/,
@@ -85,23 +107,21 @@ async function main() {
   );
   wasm.pardes_mouse(2, 0, 5, 3, 0);
   wasm.pardes_mouse(2, 1, 5, 3, 0);
-  const looked = renderer.render();
-  assert.match(looked.cells.map((cell) => cell.text).join(""), /build\.zig Save New Del/, "right-click LOOK did not open the embedded source");
+  const looked = draw();
+  assert.match(
+    looked.cells.map((cell) => cell.text).join(""),
+    /build\.zig\s+Save New Newtty Del/,
+    "right-click LOOK did not open the embedded source",
+  );
   const sourceRows = Array.from({ length: looked.rows }, (_, row) =>
     looked.cells.slice(row * looked.cols, (row + 1) * looked.cols));
   const codeRows = sourceRows.filter((row) => row.map((cell) => cell.text).join("").match(/^\s*\d+\s/));
   const codeColors = new Set(codeRows.flatMap((row) => row.slice(5).map((cell) => `${cell.fg}:${cell.attrs & 1}`)));
   assert.ok(codeColors.size >= 3, "Tree-sitter did not apply distinct syntax styles to build.zig");
-  let sawWatch = false;
-  for (let index = 0; index < 32; index += 1) {
-    const kind = wasm.pardes_effect_next();
-    if (!kind) break;
-    if (kind === 9) sawWatch = true;
-  }
-  assert.ok(sawWatch, "JS effect drain did not receive the opened file watch request");
+  assert.deepEqual(asked, [], "a plain replay asked the page for host IO");
 
   wasm.pardes_resize(41, 13);
-  const resized = renderer.render();
+  const resized = draw();
   assert.equal(resized.cols, 41);
   assert.equal(resized.rows, 13);
   assert.equal(root.children.length, 13);