Build and test wasm on CI

lib/web/test/parser-test.js

@@ -0,0 +1,31 @@
+const assert = require('assert');
+const Parser = require('../../../target/release/tree-sitter.js');
+let JavaScript, Python;
+
+before(async () => {
+  await Parser.init();
+  JavaScript = await Parser.Language.load('../../target/scratch/tree-sitter-javascript.wasm');
+  Python = await Parser.Language.load('../../target/scratch/tree-sitter-python.wasm');
+});
+
+describe("Parser", () => {
+  let parser;
+
+  beforeEach(() => {
+    parser = new Parser();
+  });
+
+  afterEach(() => {
+    parser.delete();
+  });
+
+  it("parses strings", () => {
+    const tree = parser
+      .setLanguage(JavaScript)
+      .parse("a('hi')\n");
+    assert.equal(
+      tree.rootNode.toString(),
+      "(program (expression_statement (call_expression (identifier) (arguments (string)))))"
+    );
+  });
+});