Start work on wasm binding to query API

lib/binding_web/test/query-test.js

@@ -0,0 +1,51 @@
+const {assert} = require('chai');
+let Parser, JavaScript;
+
+describe("Query", () => {
+  let parser, tree, query;
+
+  before(async () =>
+    ({Parser, JavaScript} = await require('./helper'))
+  );
+
+  beforeEach(() => {
+    parser = new Parser().setLanguage(JavaScript);
+  });
+
+  afterEach(() => {
+    parser.delete();
+    if (tree) tree.delete();
+    if (query) query.delete();
+  });
+
+  it('throws an error on invalid syntax', () => {
+    assert.throws(() => {
+      JavaScript.query("(function_declaration wat)")
+    }, "Bad syntax at offset 22: \'wat)\'...");
+    assert.throws(() => {
+      JavaScript.query("(non_existent)")
+    }, "Bad node name 'non_existent'");
+    assert.throws(() => {
+      JavaScript.query("(function_declaration non_existent:(identifier))")
+    }, "Bad field name 'non_existent'");
+  });
+
+  it('matches simple queries',  () => {
+    tree = parser.parse("function one() { two(); function three() {} }");
+    const query = JavaScript.query(`
+      (function_declaration name:(identifier) @the-name)
+    `);
+    const matches = query.exec(tree.rootNode);
+    assert.deepEqual(
+      matches.map(({pattern, captures}) => ({
+        pattern,
+        captures: captures.map(({name, node}) => ({name, text: node.text}))
+      })),
+      [
+        {pattern: 0, captures: [{name: 'the-name', text: 'one'}]},
+        // {pattern: 0, captures: [{name: 'the-function', text: 'two'}]},
+        {pattern: 0, captures: [{name: 'the-name', text: 'three'}]},
+      ]
+    );
+  });
+});