1 files changed, 48 insertions, 0 deletions
diff --git a/tests/drivers/stream_host_test.js b/tests/drivers/stream_host_test.js
new file mode 100644
index 0000000..99213e2
--- /dev/null
+++ b/tests/drivers/stream_host_test.js
@@ -0,0 +1,48 @@
+// the extension's two in-process servers (wasm and the javascript vm) stream partial diagnostics and drop a
+// check when the next message is already written. a step of either host is synchronous, so the server
+// suspends at its poll and the host lets the event loop deliver input before it goes on.
+// usage: node tests/drivers/stream_host_test.js path/to/lsp.wasm path/to/vmserver-dir
+const assert = require('assert');
+const path = require('path');
+const client = path.join(__dirname, '..', '..', 'editors', 'vscode', 'client');
+const { wasmProcess } = require(path.join(client, 'wasmproc.js'));
+const { vmProcess } = require(path.join(client, 'vmproc.js'));
+const frame = m => { const b = Buffer.from(JSON.stringify(m)); return Buffer.concat([Buffer.from('Content-Length: ' + b.length + '\r\n\r\n'), b]); };
+const doc = (n, tail) => { let t = ''; for (let i = 0; i < n; i++) t += `int f${i}(int a) { return a + ${i}; }\n`; return t + tail; };
+function run(make, steps) {
+    return new Promise(resolve => {
+        const p = make();
+        const got = [];
+        let inbox = Buffer.alloc(0);
+        p.stdout.on('data', d => {
+            inbox = Buffer.concat([inbox, d]);
+            for (;;) {
+                const e = inbox.indexOf('\r\n\r\n'); if (e < 0) return;
+                const n = parseInt(/Content-Length: (\d+)/.exec(inbox.slice(0, e).toString())[1], 10);
+                if (inbox.length < e + 4 + n) return;
+                got.push(JSON.parse(inbox.slice(e + 4, e + 4 + n).toString('utf8')));
+                inbox = inbox.slice(e + 4 + n);
+            }
+        });
+        for (const m of steps) p.stdin.write(frame(m));
+        setTimeout(() => { p.stdin.write(frame({ jsonrpc: '2.0', method: 'exit' })); setTimeout(() => resolve(got), 200); }, 4000);
+    });
+}
+const init = { jsonrpc: '2.0', id: 1, method: 'initialize', params: {} };
+const open = (uri, version, text) => ({ jsonrpc: '2.0', method: 'textDocument/didOpen', params: { textDocument: { uri, version, languageId: 'zc', text } } });
+const change = (uri, version, text) => ({ jsonrpc: '2.0', method: 'textDocument/didChange', params: { textDocument: { uri, version }, contentChanges: [{ text }] } });
+const diags = (got, uri) => got.filter(m => m.method === 'textDocument/publishDiagnostics' && m.params.uri === uri);
+(async () => {
+    const A = 'file:///host-stream.zc';
+    const ok = doc(300, 'fn main() { return f0(1); }\n');
+    const hosts = [['wasm', () => wasmProcess(path.resolve(process.argv[2]), { log: () => {} })], ['vm', () => vmProcess(path.resolve(process.argv[3]), { log: () => {} })]];
+    for (const [name, make] of hosts) {
+        let got = await run(make, [init, open(A, 1, 'int broken( { }\n' + ok)]);
+        let d = diags(got, A);
+        assert.ok(d.length >= 2 && d[0].params.diagnostics.some(x => x.severity === 1), name + ': a large check streams: ' + d.length);
+        got = await run(make, [init, open(A, 1, ok), change(A, 2, 'fn main() { return 0; }\n')]);
+        d = diags(got, A);
+        assert.ok(d.length >= 1 && d.every(m => m.params.version === 2), name + ': the stale check is dropped: ' + JSON.stringify(d.map(m => m.params.version)));
+        console.log('ok   ' + name + ' server streams and drops stale checks');
+    }
+})();